Lower ionospheric resonance caused by Pekeris wave induced by 2022 Tonga volcanic eruption
Hiroyo Ohya, Fuminori Tsuchiya, Tamio Takamura, Hiroyuki Shinagawa, Yukihiro Takahashi, Alfred B. Chen
Scientific Reports, 14, 1, Springer Science and Business Media LLC, 16 Jul. 2024
Scientific journal, Abstract

The submarine volcano Hunga Tonga–Hunga Ha’apai erupted explosively on January 15, 2022, offering a unique opportunity to investigate interactions between the atmosphere and ionosphere caused by Lamb and Pekeris waves. However, the resonance of Pekeris waves has not been previously detected. In this study, we applied a multi-point monitoring approach focusing on the lower ionosphere and atmospheric electric field. Here we show observed oscillations of 100–200 s in manmade transmitter signals and the magnetic and atmospheric electric fields, which were caused by Pekeris waves. However, no corresponding changes with the period of 100–200 s in atmospheric pressure due to Pekeris waves were observed on the ground. A simulation of neutral wind revealed Pekeris waves oscillating near the mesopause, suggesting resonance. Therefore, the oscillation in atmospheric electric field is interpreted that the resonance in the lower ionosphere was projected onto the Earth's surface via a global electric circuit.

4-years lightning hunt in Venus
Yukihiro Takahashi, Masataka Imai, Mitsuteru Sato, Tastuaki Oono
02 May 2024

Estimation of the drift rate and intensity of Neptune's storm by Pirika telescope
Yuki Sato, Yukihiro Takahashi, Mitsuteru Sato, Seiko Takagi, Masataka Imai, Tatsuharu Ono
02 May 2024

Radiometric Calibration for a Multispectral Sensor Onboard RISESAT Microsatellite Based on Lunar Observations
Masataka Imai, Junichi Kurihara, Toru Kouyama, Toshinori Kuwahara, Shinya Fujita, Yuji Sakamoto, Yuji Sato, Sei-Ichi Saitoh, Takafumi Hirata, Hirokazu Yamamoto, Yukihiro Takahashi
Sensors, 21, 7, 2429, 2429, MDPI AG, 01 Apr. 2021
Scientific journal, Radiometric calibration utilizing the Moon as a reference source is termed as lunar calibration. It is a useful method for evaluating the performance of optical sensors onboard satellites orbiting the Earth. Lunar calibration provides sufficient radiometric calibration opportunities without requiring any special equipment, and is suitable for nano/microsatellites. This study applies lunar calibration to a multispectral sensor, Ocean Observation Camera (OOC), on board a microsatellite named Rapid International Scientific Experiment Satellite. Simulating the brightness of the Moon based on the RObotic Lunar Observatory and SELENE/Spectrum Profiler models, sensitivity degradation was proven to be negligible in any of the four spectral bands of the OOC with the sensor temperature correction. A bluing trend in the OOC’s sensor sensitivity was revealed, indicating a shorter observation wavelength shows larger irradiance. Comparing the top-of-atmosphere reflectance of Railroad Valley Playa with the Radiometric Calibration Network dataset revealed that the derived calibration parameter from the lunar calibration was valid for correcting the bluing trend in the visible range. Although the lunar and vicarious calibration parameters for the infrared band were unexpectedly inconsistent, lunar calibration could potentially contribute toward estimating the contaminated background radiance in the Earth observation images.

Road to the first star: Venus orbiter from Japan (46) - LAC detected lightning flash in Venus? -
Takahashi Y., Imai M., Sato M.
Planetary People - The Japanese Society for Planetary Sciences, 30, 2, 72, 73, The Japanese Society for Planetary Sciences, 2021
Japanese,

⾦星に雷放電の有無に決着をつけるべく，世界初の惑星雷放電発光観測装置LACは⾦星周回軌道で観測を継続してきました．観測開始から約4年になる2020年3月1日に，最初にして唯一（2021年4月末日現在）の突発的な発光現象を記録しました．果たして雷はあったのでしょうか？

Estimation of the IC to CG Ratio Using JEM‐GLIMS and Ground‐Based Lightning Network Data
K. Bandholnopparat, M. Sato, T. Adachi, T. Ushio, Y. Takahashi
Journal of Geophysical Research: Atmospheres, 125, 23, American Geophysical Union (AGU), 16 Dec. 2020
Scientific journal

Inflight Radiometric Calibration for a Multi-Band Sensor Onboard Risesat with the Moon
Masataka Imai, Toru Kouyama, Junichi Kurihara, Toshinori Kuwahara, Shinya Fujita, Yuji Sakamoto, Sei Ichi Saitoh, Takafumi Hirata, Yukihiro Takahashi
International Geoscience and Remote Sensing Symposium (IGARSS), 6222, 6225, 26 Sep. 2020
International conference proceedings, Radiometric calibration with the Moon (called the lunar calibration) is a promising method for evaluating the performance of instruments onboard satellites orbiting around the Earth. In particular, the lunar calibration can provide inflight radiometric calibration opportunities for nano/microsatellites whose priorities are technical demonstrations and scientific observations during rather a short lifetime. In this study, we have applied the lunar calibration to a recently launched microsatellite named RISESAT. RISESAT had observed the Moon every month for a half year after the launch with an onboard instrument OOC. By simulating the Moon brightness for each observation based on the ROLO and SELENE/SP Moon models, we succeeded to measure < 2 % of a small degradation in four months. Further comparison of the observation and the simulation irradiance of the Moon revealed the bluing trend in the OOC's inter-band ratio.

HO Generation Above Sprite‐Producing Thunderstorms Derived from Low‐Noise SMILES Observation Spectra
T. Yamada, T. O. Sato, T. Adachi, H. Winkler, K. Kuribayashi, R. Larsson, N. Yoshida, Y. Takahashi, M. Sato, A. B. Chen, R. R. Hsu, Y. Nakano, T. Fujinawa, S. Nara, Y. Uchiyama, Y. Kasai
Geophysical Research Letters, 47, 3, American Geophysical Union (AGU), 16 Feb. 2020
Scientific journal

Commercial Uncooled Microbolometer Camera Applied to 50-kg Class Satellite
Tetsuya Fukuhara, Yuji Sakamoto, Toshinori Kuwahara, Nobuo Sugimura, Kazuya Yoshida, Yukihiro Takahashi
IEEE GEOSCIENCE AND REMOTE SENSING LETTERS, 17, 2, 332, 336, IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, Feb. 2020
English, Scientific journal, The commercial thermal infrared camera mounting the uncooled microbolometer array (UMBA), which detects thermal wavelengths from 8 to 14 mu m , was modified for space use and applied to the small earth-observing satellite called Rising-2. The satellite was launched in 2014, and the camera successfully took 17 of the cloud top and 3 of the land images from the sun-synchronous orbit. Observed brightness temperatures based on the reference data acquired in the laboratory before the launch have been compared with verified products derived from the Japanese meteorological satellite called MTSAT-2, and we confirmed that the UMBA could sense brightness temperature distribution of the target. The demonstration of the commercial thermal infrared camera in orbit would innovate in the development of space instruments as a new approach.

A High Spatial Resolution Multispectral Sensor on the RISESAT Microsatellite
KURIHARA Junichi, IP Wing-Huen, KUWAHARA Toshinori, FUJITA Shinya, SATO Yuji, HANYU Kosuke, SAKAL Morokot, MURATA Yu, TOMIO Hannah, TAKAHASHI Yukihiro
TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN, 18, 5, 186, 191, THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, 2020
English,

Nano/microsatellites play a significant role in Earth observation with the emerging constellation of high spatial resolution satellites. However, there are technological limitations in their spectral resolution. In this paper, we present an overview of a high spatial resolution multispectral sensor, the High-Precision Telescope (HPT), which was developed originally for the RISING-2 microsatellite and subsequently improved for the Rapid International Scientific Experiment Satellite (RISESAT) microsatellite. The HPTs were also installed on the DIWATA-1 and DIWATA-2 microsatellites, but they are different from those in the RISING-2 and RISESAT microsatellites in terms of number of spectral bands. The HPT on the RISESAT has the largest number of spectral bands in a series of the high spatial resolution multispectral sensors. The RISESAT was successfully launched by the Epsilon-4 launch vehicle on 18 January 2019. The preliminary results obtained in the commissioning phase of the operation demonstrate the expected performance of the HPT.

Unmanned Aerial Vehicle (UAV)-Based Hyperspectral Imaging System for Precision Agriculture and Forest Management
Junichi Kurihara, Tetsuro Ishida, Yukihiro Takahashi
Unmanned Aerial Vehicle: Applications in Agriculture and Environment, 25, 38, Springer International Publishing, 2020
In book

Planetary‐Scale Variations in Winds and UV Brightness at the Venusian Cloud Top: Periodicity and Temporal Evolution
Masataka Imai, Toru Kouyama, Yukihiro Takahashi, Atsushi Yamazaki, Shigeto Watanabe, Manabu Yamada, Takeshi Imamura, Takehiko Satoh, Masato Nakamura, Shin‐ya Murakami, Kazunori Ogohara, Takeshi Horinouchi
Journal of Geophysical Research: Planets, American Geophysical Union ({AGU}), 31 Oct. 2019, [Peer-reviewed]
Scientific journal

Constraints on Venus Lightning From Akatsuki's First 3 Years in Orbit
Ralph D. Lorenz, Masataka Imai, Yukihiro Takahashi, Mitsuteru Sato, Atsushi Yamazaki, Takao M. Sato, Takeshi Imamura, Takehiko Satoh, Masato Nakamura
Geophysical Research Letters, 46, 14, 7955, 7961, American Geophysical Union ({AGU}), Jul. 2019, [Peer-reviewed]
Scientific journal

Characteristics Evaluation and Performance Improvement Method of Balloon-Borne Telescope Pointing Control System
Toshihiko NAKANO, Makoto TAGUCHI, Yasuhiro SHOJI, Mao TAKAMURA, Daiki SUNAGUCHI, Masataka IMAI, Makoto WATANABE, Yukihiro TAKAHASHI, Yuji SAKAMOTO, Kazuya YOSHIDA
TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN, 17, 1, 51, 56, Japan Society for Aeronautical and Space Sciences, 2019
Scientific journal

Initiation of a lightning search using the lightning and airglow camera onboard the Venus orbiter Akatsuki
Yukihiro Takahashi, Mitsuteru Sato, Masataka Imai, Ralph Lorenz, Yoav Yair, Karen Aplin, Georg Fischer, Masato Nakamura, Nobuaki Ishii, Takumi Abe, Takehiko Satoh, Takeshi Imamura, Chikako Hirose, Makoto Suzuki, George L. Hashimoto, Naru Hirata, Atsushi Yamazaki, Takao M. Sato, Manabu Yamada, Shin-ya Murakami, Yukio Yamamoto, Tetsuya Fukuhara, Kazunori Ogohara, Hiroki Ando, Ko-ichiro Sugiyama, Hiroki Kashimura, Shoko Ohtsuki
Earth, Planets and Space, 70, 1, Springer Berlin Heidelberg, 01 Dec. 2018, [Peer-reviewed]
English, Scientific journal, The existence of lightning discharges in the Venus atmosphere has been controversial for more than 30 years, with many positive and negative reports published. The lightning and airglow camera (LAC) onboard the Venus orbiter, Akatsuki, was designed to observe the light curve of possible flashes at a sufficiently high sampling rate to discriminate lightning from other sources and can thereby perform a more definitive search for optical emissions. Akatsuki arrived at Venus during December 2016, 5 years following its launch. The initial operations of LAC through November 2016 have included a progressive increase in the high voltage applied to the avalanche photodiode detector. LAC began lightning survey observations in December 2016. It was confirmed that the operational high voltage was achieved and that the triggering system functions correctly. LAC lightning search observations are planned to continue for several years.

Start of lightning hunting by LAC / Akatsuki　　　　　　　　　　　　　　　
Takahashi, Y, M. Sato, M. Imai, R. Lorenz, Y. Yair, K. Aplin, G. Fischer, M. Nakamura, N. Ishii, T. Abe, T. Satoh, T. Imamura, C. Hirose, M. Suzuki, G. L. Hashimoto, N. Hitrata, A. Yamazaki, T. M. Sato, M. Yamada, S. Murakami, Y. Yamamoto, T. Fukuhara, K. Ogohara, H. Ando, K. Sugiyama, H. Kashimura, S. Ohtsuki
Earth, Planets and Space, 70:88, May 2018, [Peer-reviewed]
English, Scientific journal

HPT: A High Spatial Resolution Multispectral Sensor for Microsatellite Remote Sensing
Junichi Kurihara, Yukihiro Takahashi, Yuji Sakamoto, Toshinori Kuwahara, Kazuya Yoshida
Sensors, 18, 2, 619, 619, MDPI AG, 18 Feb. 2018
Scientific journal, Although nano/microsatellites have great potential as remote sensing platforms, the spatial and spectral resolutions of an optical payload instrument are limited. In this study, a high spatial resolution multispectral sensor, the High-Precision Telescope (HPT), was developed for the RISING-2 microsatellite. The HPT has four image sensors: three in the visible region of the spectrum used for the composition of true color images, and a fourth in the near-infrared region, which employs liquid crystal tunable filter (LCTF) technology for wavelength scanning. Band-to-band image registration methods have also been developed for the HPT and implemented in the image processing procedure. The processed images were compared with other satellite images, and proven to be useful in various remote sensing applications. Thus, LCTF technology can be considered an innovative tool that is suitable for future multi/hyperspectral remote sensing by nano/microsatellites.

HPT: A High Spatial Resolution Multispectral Sensor for Microsatellite Remote Sensing　　　　　　　　　　　　　　　
Kurihara Junichi, Takahashi Yukihiro, Sakamoto Yuji, KUWAHARA Toshinori, Kazuya Yoshida
Sensors, 619, 18, 1, 11, Feb. 2018, [Peer-reviewed]
English, Scientific journal

Matching algorithms of ELF-LEMPs and lightning geo-location data
Tsurushima, D, N. Honma, F. Tsuchiya, M. Sato, Y. Takahashi
IEEJ Transactions on Power and Energy, 138, 5, 339, 345, 2018, [Peer-reviewed]
English, Scientific journal

Discrimination of areas infected with coffee leaf rust using a vegetation index
Katsuhama, N, M. Imai, N. Naruse, Y. Takahashi
J. Remote Sensing Letters, 9, 1186, 1194, 2018, [Peer-reviewed]

Detection of Small Wildfire by Thermal Infrared Camera With the Uncooled Microbolometer Array for 50-kg Class Satellite
Tetsuya Fukuhara, Toru Kouyama, Soushi Kato, Ryosuke Nakamura, Yukihiro Takahashi, Hiroaki Akiyama
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, 55, 8, 4314, 4324, IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, Aug. 2017, [Peer-reviewed]
English, Scientific journal, The thermal infrared camera with the uncooled microbolometer array based on commercial products has been developed in a laboratory of a Japanese university and mounted to a 50-kg class small satellite specialized for discovering wildfire. It has been launched in 2014 and successfully detected considerable hotspots not only wildfire but also volcanoes. Brightness temperature derived from observation has been verified, and the scale of observed wildfire has been provisionally presumed; the smallest wildfire ever detected has a flame zone less than similar to 300 m(2) and the fire radiative power = similar to 35.4 mW. It is 1/30th the size of the initial requirement estimated in the design process. Our thermal infrared camera developed in a short time with low cost has attained enough ability to discover small wildfire which is suppressive at initial attack.

Sprites identification and their spatial distributions in JEM-GLIMS nadir observations
Mitsuteru Sato, Toru Adachi, Tomoo Ushio, Takeshi Morimoto, Masayuki Kikuchi, Hiroshi Kikuchi, Makoto Suzuki, Atsushi Yamazaki, Yukihiro Takahashi, Ryohei Ishida, Yuji Sakamoto, Kazuya Yoshida, Yasuhide Hobara
TERRESTRIAL ATMOSPHERIC AND OCEANIC SCIENCES, 28, 4, 545, 561, CHINESE GEOSCIENCE UNION, Aug. 2017, [Peer-reviewed]
English, Scientific journal, The Global Lightning and Sprite Measurements on the Japanese Experiment Module (JEM-GLIMS) started continuous nadir observations of lightning and transient luminous events (TLEs) at the International Space Station (ISS) in November 2012 and completed the observations in August 2015. As JEM-GLIMS uses the nadir observation technique, the JEM-GLIMS optical instruments simultaneously measure both incomparably intense lightning emissions and weak sprite emissions. We adopted combined data analytical methods to distinguish between these two types of emissions: (1) a subtraction of the wideband LSI-1 image from the narrowband LSI-2 image, (2) a calculation of the intensity ratio between different photometer channels, and (3) an estimation of the charge moment change (CMC) of the suspected sprite-producing CG discharge. This report presents as a case study one sprite event detected at 19: 50: 40.30580 UT on 28 September 2013 and identified using the above analytical methods. From the results derived from detailed data analyses, we judged that the optical emission measured by LSI-2 is a sprite emission. We carried out the geometry conversion toward the LSI-1 and subtracted images and found that the sprite emission location shifts by 3.5 km from the peak lightning emission location, which agree with the previous reports. The detailed horizontal distributions of sprites and the relationship between the sprite location and the parent lightning location are quantitatively revealed for the first time.

Identification of sprites in JEM-GLIMS nadir observations and their spatial distributions　　　　　　　　　　　　　　　
Sato, M, T. Adachi, T. Ushio, T. Morimoto, M. Kikuchi, H. Kikuchi, M. Suzuki, A. Yamazaki, Y. Takahashi, R. Ishida, Y. Sakamoto, K. Yoshida, Y. Hobara
Terrestrial, Atmospheric and Oceanic Sciences, 28, 545, 561, Aug. 2017, [Peer-reviewed]
English, Scientific journal

Solar 27-day rotational period detected in wide-area lightning activity in Japan
Hiroko Miyahara, Chika Higuchi, Toshio Terasawa, Ryuho Kataoka, Mitsuteru Sato, Yukihiro Takahashi
ANNALES GEOPHYSICAE, 35, 3, COPERNICUS GESELLSCHAFT MBH, Apr. 2017, [Peer-reviewed]
English, Scientific journal, A signal of the 27-day solar rotational period is often observed in cloud and lightning activities over the globe. Here we provide evidence of the 27-day periodicity of lightning activity in Japan using daily observational records of lightning for AD1989-2015. The 27-day period is detected with 4.2 standard deviations, but only in wide-area lightning activity covering more than a 10(5) km(2). The 27-day signal is more prominent around the maxima of solar decadal cycles.

Multidisciplinary field research in Kabwe, Zambia, towards better understanding of lead contamination of the city - A short report from a field survey
Yoshitaka Uchida, Kawawa Banda, Toru Hamamoto, Yui Yoshii, Kabenuka Munthali, Mukuka Mwansa, Moses Mukuka, Mubanga Mutale, Nobuyasu Naruse, Yukihiro Takahashi
bioRxiv, Jan. 2017
English, Scientific journal

Studies of dust and discharges around a Martian rover with onboard hazard analyses using electromagnetic and acoustic wave measurements　　　　　　　　　　　　　　　
Yamamoto, M, M. Sato, K. Ishisaka, Y. Takahashi, K. Ogohara, M. Kamogawa, H. Miyamoto
Ttansactions of the Japan Society for Aeronatical and Space Sciences, 14, 30, 41, 45, Oct. 2016, [Peer-reviewed]
English, Scientific journal

The Imager for Sprites and Upper Atmospheric Lightning (ISUAL)
H. U. Frey, S. B. Mende, S. E. Harris, H. Heetderks, Y. Takahashi, H. -T. Su, R. -R. Hsu, A. B. Chen, H. Fukunishi, Y. -S. Chang, L. -C. Lee
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 121, 8, 8134, 8145, AMER GEOPHYSICAL UNION, Aug. 2016, [Peer-reviewed]
English, Scientific journal, The Imager for Sprites and Upper Atmospheric Lightning (ISUAL) was the first specifically dedicated instrument to observe lightning-induced transient luminous events (TLE): sprites, elves, halos, and gigantic jets from space. The Imager is an intensified CCD system operating in the visible wavelength region with a filter wheel to select from six positions with filters. The Imager has a 5 degrees x 20 degrees (vertical times horizontal) field of view. The spectrophotometer (SP) is populated with six photometers with individual filters for emissions from the far ultraviolet to the near infrared. An array photometer with two channels operating in the blue and red provides altitude profiles of the emission over 16 altitude bins each. The Associated Electronics Package (AEP) controls instrument functions and interfaces with the spacecraft. ISUAL was launched 21 May 2004 into a Sun-synchronous 890 km orbit on the Formosat-2 satellite and has successfully been collecting data ever since. ISUAL is running on the nightside of the orbit and is pointed to the east of the orbit down toward the limb. The instrument runs continuously and writes data to a circular buffer. Whenever the SP detects a sudden signal increase above a preset threshold, a trigger signal is generated that commands the system to keep the data for about 400 ms starting from similar to 50 ms before the trigger. Over its lifetime of similar to 11 years the system recorded thousands of TLE and also successfully observed aurora and airglow.

Identifying the occurrence of lightning and transient luminous events by nadir spectrophotometric observation
Adachi Toru, Sato Mitsuteru, Ushio Tomoo, Yamazaki Atsushi, Suzuki Makoto, Kikuchi Masayuki, Takahashi Yukihiro, Inan Umran S, Linscott Ivan, Hobara Yasuhide, Frey Harald U, Mende Stephen B, Chen Alfred B, Hsu Rue-Ron, Kusunoki Kenichi
JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS, 145, 85, 97, Jul. 2016, [Peer-reviewed]
Scientific journal, © 2016 Elsevier Ltd. We propose a new technique to identify the occurrence of lightning and transient luminous events (TLEs) using multicolor photometric data obtained by space borne nadir measurements. We estimate the spectral characteristics of lightning and TLEs by converting the optical data obtained by the ISUAL limb experiment to the GLIMS nadir geometry. We find that the estimated spectral shapes of TLE-accompanied lightning are clearly different from those of pure lightning. The obtained results show that (1) the intensity of FUV signals and (2) the ratio of 337/red (609-753 nm) spectral irradiance are useful to identify the occurrence of TLEs. The occurrence probabilities of TLEs are 10%, 40%, 80%, in the case of lightning events having the 337/red spectral irradiance ratio of 0.95, 2.95, 14.79, respectively. By using the 60% criterion of the 337/red ratio and the existence of FUV emissions, we classify the 1039 GLIMS-observed lightning events into 828 pure lightning and 211 TLE-accompanied lightning. Since the GLIMS trigger level is adjusted to observe extremely-bright events, the occurrence probability of TLEs obtained here most probably reflects the characteristics of energetic lightning. The estimated global map is consistent with previously determined distributions: the highest activities of lightning and TLEs are found over the North/South American continents, African continent, and Asian maritime regions. While the absolute occurrence number of pure lightning and TLE-accompanied lightning are found to maximize in the equatorial region, the occurrence probability of TLEs possibly increase somewhat in the mid-latitude region. Since the occurrence probabilities of TLEs are higher over the ocean than over land, it is likely that the GLIMS-observed TLEs are due primarily to elves which tends to occur more frequently over the ocean.

AKATSUKI returns to Venus
Masato Nakamura, Takeshi Imamura, Nobuaki Ishii, Takumi Abe, Yasuhiro Kawakatsu, Chikako Hirose, Takehiko Satoh, Makoto Suzuki, Munetaka Ueno, Atsushi Yamazaki, Naomoto Iwagami, Shigeto Watanabe, Makoto Taguchi, Tetsuya Fukuhara, Yukihiro Takahashi, Manabu Yamada, Masataka Imai, Shoko Ohtsuki, Kazunori Uemizu, George L. Hashimoto, Masahiro Takagi, Yoshihisa Matsuda, Kazunori Ogohara, Naoki Sato, Yasumasa Kasaba, Toru Kouyama, Naru Hirata, Ryosuke Nakamura, Yukio Yamamoto, Takeshi Horinouchi, Masaru Yamamoto, Yoshi-Yuki Hayashi, Hiroki Kashimura, Ko-ichiro Sugiyama, Takeshi Sakanoi, Hiroki Ando, Shin-ya Murakami, Takao M. Sato, Seiko Takagi, Kensuke Nakajima, Javier Peralta, Yeon Joo Lee, Junichi Nakatsuka, Tsutomu Ichikawa, Kozaburo Inoue, Tomoaki Toda, Hiroyuki Toyota, Sumitaka Tachikawa, Shinichiro Narita, Tomoko Hayashiyama, Akiko Hasegawa, Yukio Kamata
Earth, Planets and Space, 68, 1, Springer Science $\mathplus$ Business Media, May 2016, [Peer-reviewed]
English, Scientific journal, AKATSUKI is the Japanese Venus Climate Orbiter that was designed to investigate the climate system of Venus. The orbiter was launched on May 21, 2010, and it reached Venus on December 7, 2010. Thrust was applied by the orbital maneuver engine in an attempt to put AKATSUKI into a westward equatorial orbit around Venus with a 30-h orbital period. However, this operation failed because of a malfunction in the propulsion system. After this failure, the spacecraft orbited the Sun for 5 years. On December 7, 2015, AKATSUKI once again approached Venus and the Venus orbit insertion was successful, whereby a westward equatorial orbit with apoapsis of similar to 440,000 km and orbital period of 14 days was initiated. Now that AKATSUKI's long journey to Venus has ended, it will provide scientific data on the Venusian climate system for two or more years. For the purpose of both decreasing the apoapsis altitude and avoiding a long eclipse during the orbit, a trim maneuver was performed at the first periapsis. The apoapsis altitude is now similar to 360,000 km with a periapsis altitude of 1000-8000 km, and the period is 10 days and 12 h. In this paper, we describe the details of the Venus orbit insertion-revenge 1 (VOI-R1) and the new orbit, the expected scientific information to be obtained at this orbit, and the Venus images captured by the onboard 1-mu m infrared camera, ultraviolet imager, and long-wave infrared camera 2 h after the successful initiation of the VOI-R1.

Horizontal distributions of sprites derived from the JEM-GLIMS nadir observations
M. Sato, M. Mihara, T. Adachi, T. Ushio, T. Morimoto, M. Kikuchi, H. Kikuchi, M. Suzuki, A. Yamazaki, Y. Takahashi, U. Inan, I. Linscott, R. Ishida, Y. Sakamoto, K. Yoshida, Y. Hobara
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 121, 7, 3171, 3194, AMER GEOPHYSICAL UNION, Apr. 2016, [Peer-reviewed]
English, Scientific journal, Global Lightning and Sprite Measurements on Japanese Experiment Module (JEM-GLIMS) started the nadir observations of lightning discharges and transient luminous events (TLEs) from the International Space Station (ISS) since November 2012. In the nadir observations, JEM-GLIMS optical instruments have to simultaneously detect incomparably intense lightning emissions and weak TLE emissions. To distinguish TLEs, especially sprite events, from lightning events, combined data analytical methods are adopted: (1) a subtraction of the wideband camera image from the narrowband camera image, (2) a calculation of the intensity ratio between different photometer channels, and (3) an estimation of the polarization and charge moment changes for the TLE-producing lightning discharges. We succeeded in identifying numbers of sprite events using the combined analytical methods, and here we report three sprite events detected by JEM-GLIMS as a case study. In the subtracted images, sprite emissions are located over the area of the sprite-producing lightning emissions. However, these sprites and sprite-producing lightning discharges did not occur at the nadir point of the ISS. For this reason, the geometry conversion of the sprite and sprite-producing lightning emissions as observed from the point just over the sprite-producing lightning discharges is performed. In the geometry-converted images, the locations of the sprite emissions are clearly displaced by 8-20km from the peak positions of the sprite-producing lightning emissions. Thus, the first quantitative spatial distributions of sprites and sprite-producing lightning discharges from the JEM-GLIMS nadir observations are revealed.

Development of Science Education and Research Activity Program for High-School Students using Information and Communication Technology
Nobuyasu Naruse, Fumihito Ikeda, Kunimasa Yamada, Naohiro Iida, Yukihiro Takahahi, Makoto Suzuki
J. Higher Education and Lifelong Learning, 23, 23, 101, 107, 北海道大学高等教育推進機構, Mar. 2016, [Peer-reviewed]
Japanese, Scientific journal

Micro-Satellite and Spectral Imager with Liquid Crystal Tunable Filter
TAKAHASHI Yukihiro
Journal of The Society of Instrument and Control Engineers, 55, 9, 792, 796, The Society of Instrument and Control Engineers, 2016
Japanese

FUJIN-2:Balloon Borne Telescope for Optical Observation of Planets
Yasuhiro SHOJI, Makoto TAGUCHI, Toshihiko NAKANO, Atsunori MAEDA, Masataka IMAI, Yuya GOUDA, Makoto WATANABE, Yukihiro TAKAHASHI, Yuji SAKAMOTO, Kazuya YOSHIDA
TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN, 14, ists30, Pk_95, Pk_102, Japan Society for Aeronautical and Space Sciences, 2016
Scientific journal

Ground-based observation of the cyclic nature and temporal variability of planetary-scale UV features at the Venus cloud top level
Imai Masataka, Takahashi Yukihiro, Watanabe Makoto, Kouyama Toru, Watanabe Shigeto, Gouda Shuhei, Gouda Yuya
Icarus, 278, 204, 214, ACADEMIC PRESS INC ELSEVIER SCIENCE, 2016, [Peer-reviewed]
English, Scientific journal, A planetary-scale bright and dark UV feature, known as the "Y-feature," rotates around Venus with a period of 4-5 days and has been long-time interpreted as planetary waves. When assuming this, its rotation period and spatial structure might help to understand the propagation of the planetary-scale waves and find out their role in the acceleration-deceleration of the zonal wind speed, which is essential for understanding the super-rotation of the planet. The rotation period of the UV feature varied over the course of observation by the Pioneer Venus orbiter. However, in previous explorations of Venus such as Pioneer Venus and Venus Express, the spacecraft were operated in nearly fixed inertial space. As a result, the periodicity variations on sub-yearly timescales (one Venusian year is 224 Earth days) were obscured by the limitations of continuous dayside observations. We newly conducted six periods of ground -based Venus imaging observations at 365 nm from mid-August 2013 to the end of June 2014. Each observation period spanned over half or one month, enabling long-term monitoring of Venus' atmosphere above the equator region. Distributions of the relative brightness were obtained from the equatorial (EQ) to mid-latitudinal regions in both hemispheres, and from the cyclical variations of these distributions we deduced the rotation periods of the UV features of the cloud tops brightness. The relative brightness exhibited periods of 5.2 and 3.5 days above 90% of significance. The relative intensities of these two significant components also seemed subject to temporal variations. Although the 3.5-day component considered persists throughout the observation periods, its dominance over the longer period varied in a cyclic fashion. The prevailing first significant mode seems to change from 5.2-day waves to 3.5-day waves in about nine months, which is clearly inconsistent with the Venusian year. Clear periodic perturbations, indicating stability of the planetary-scale UV-feature, were observed only in the presence of single longer or shorter periodic waves. During the transition periods of dominant-wave changing, the amplitude of the relative brightness was largely changed. This can be explained by the deformation of the Y-shaped UV feature as observed by Pioneer Venus in 1979. (C) 2016 Elsevier Inc. All rights reserved.

Relation between charge amounts of lightning discharges derived from ELF waveform data and severe weather
Shimizu, C, M. Sato, Y. Hongo, F. Tsuchiya, Y. Takahashi
IEEJ Transactions, 2016, [Peer-reviewed]
Japanese, Scientific journal, in press

Space experiment TUS on board the Lomonosov satellite as pathfinder of JEM-EUSO
J. H. Adams, S. Ahmad, J. -N. Albert, D. Allard, L. Anchordoqui, V. Andreev, A. Anzalone, Y. Arai, K. Asano, M. Ave Pernas, P. Baragatti, P. Barrillon, T. Batsch, J. Bayer, R. Bechini, T. Belenguer, R. Bellotti, K. Belov, A. A. Berlind, M. Bertaina, P. L. Biermann, S. Biktemerova, C. Blaksley, N. Blanc, J. Blecki, S. Blin-Bondil, J. Bluemer, P. Bobik, M. Bogomilov, M. Bonamente, M. S. Briggs, S. Briz, A. Bruno, F. Cafagna, D. Campana, J-N. Capdevielle, R. Caruso, M. Casolino, C. Cassardo, G. Castellini, C. Catalano, O. Catalano, A. Cellino, M. Chikawa, M. J. Christl, D. Cline, V. Connaughton, L. Conti, G. Cordero, H. J. Crawford, R. Cremonini, S. Csorna, S. Dagoret-Campagne, A. J. de Castro, C. De Donato, C. de la Taille, C. De Santis, L. del Peral, A. Dell'Oro, N. De Simone, M. Di Martino, G. Distratis, F. Dulucq, M. Dupieux, A. Ebersoldt, T. Ebisuzaki, R. Engel, S. Falk, K. Fang, F. Fenu, I. Fernandez-Gomez, S. Ferrarese, D. Finco, M. Flamini, C. Fornaro, A. Franceschi, J. Fujimoto, M. Fukushima, P. Galeotti, G. Garipov, J. Geary, G. Gelmini, G. Giraudo, M. Gonchar, C. Gonzalez Alvarado, P. Gorodetzky, F. Guarino, A. Guzman, Y. Hachisu, B. Harlov, A. Haungs, J. Hernandez Carretero, K. Higashide, D. Ikeda, H. Ikeda, N. Inoue, S. Inoue, A. Insolia, F. Isgro, Y. Itow, E. Joven, E. G. Judd, A. Jung, F. Kajino, T. Kajino, I. Kaneko, Y. Karadzhov, J. Karczmarczyk, M. Karus, K. Katahira, K. Kawai, Y. Kawasaki, B. Keilhauer, B. A. Khrenov, Jeong-Sook Kim, Soon-Wook Kim, Sug-Whan Kim, M. Kleifges, P. A. Klimov, D. Kolev, I. Kreykenbohm, K. Kudela, Y. Kurihara, A. Kusenko, E. Kuznetsov, M. Lacombe, C. Lachaud, J. Lee, J. Licandro, H. Lim, F. Lopez, M. C. Maccarone, K. Mannheim, D. Maravilla, L. Marcelli, A. Marini, O. Martinez, G. Masciantonio, K. Mase, R. Matev, G. Medina-Tanco, T. Mernik, H. Miyamoto, Y. Miyazaki, Y. Mizumoto, G. Modestino, A. Monaco, D. Monnier-Ragaigne, J. A. Morales de los Rios, C. Moretto, V. S. Morozenko, B. Mot, T. Murakami, M. Nagano, M. Nagata, S. Nagataki, T. Nakamura, T. Napolitano, D. Naumov, R. Nava, A. Neronov, K. Nomoto, T. Nonaka, T. Ogawa, S. Ogio, H. Ohmori, A. V. Olinto, P. Orleanski, G. Osteria, M. I. Panasyuk, E. Parizot, I. H. Park, H. W. Park, B. Pastircak, T. Patzak, T. Paul, C. Pennypacker, S. Perez Cano, T. Peter, P. Picozza, T. Pierog, L. W. Piotrowski, S. Piraino, Z. Plebaniak, A. Pollini, P. Prat, G. Prevot, H. Prieto, M. Putis, P. Reardon, M. Reyes, M. Ricci, I. Rodriguez, M. D. Rodriguez Frias, F. Ronga, M. Roth, H. Rothkaehl, G. Roudil, I. Rusinov, M. Rybczynski, M. D. Sabau, G. Saez Cano, H. Sagawa, A. Saito, N. Sakaki, M. Sakata, H. Salazar, S. Sanchez, A. Santangelo, L. Santiago Cruz, M. Sanz Palomino, O. Saprykin, F. Sarazin, H. Sato, M. Sato, T. Schanz, H. Schieler, V. Scotti, A. Segreto, S. Selmane, D. Semikoz, M. Serra, S. Sharakin, T. Shibata, H. M. Shimizu, K. Shinozaki, T. Shirahama, G. Siemieniec-Ozieblo, H. H. Silva Lopez, J. Sledd, K. Slominska, A. Sobey, T. Sugiyama, D. Supanitsky, M. Suzuki, B. Szabelska, J. Szabelski, F. Tajima, N. Tajima, T. Tajima, Y. Takahashi, H. Takami, M. Takeda, Y. Takizawa, C. Tenzer, O. Tibolla, L. Tkachev, H. Tokuno, T. Tomida, N. Tone, S. Toscano, F. Trillaud, R. Tsenov, Y. Tsunesada, K. Tsuno, T. Tymieniecka, Y. Uchihori, M. Unger, O. Vaduvescu, J. F. Valdes-Galicia, P. Vallania, L. Valore, G. Vankova, C. Vigorito, L. Villasenor, P. von Ballmoos, S. Wada, J. Watanabe, S. Watanabe, J. Watts, M. Weber, T. J. Weiler, T. Wibig, L. Wiencke, M. Wille, J. Wilms, Z. Wlodarczyk, T. Yamamoto, Y. Yamamoto, J. Yang, H. Yano, I. V. Yashin, D. Yonetoku, K. Yoshida, S. Yoshida, R. Young, M. Yu. Zotov, A. Zuccaro Marchi
EXPERIMENTAL ASTRONOMY, 40, 1, 315, 326, SPRINGER, Nov. 2015, [Peer-reviewed]
English, Scientific journal, Space-based detectors for the study of extreme energy cosmic rays (EECR) are being prepared as a promising new method for detecting highest energy cosmic rays. A pioneering space device - the "tracking ultraviolet set-up" (TUS) - is in the last stage of its construction and testing. The TUS detector will collect preliminary data on EECR in the conditions of a space environment, which will be extremely useful for planning the major JEM-EUSO detector operation.

Calibration aspects of the JEM-EUSO mission
J. H. Adams, S. Ahmad, J. -N. Albert, D. Allard, L. Anchordoqui, V. Andreev, A. Anzalone, Y. Arai, K. Asano, M. Ave Pernas, P. Baragatti, P. Barrillon, T. Batsch, J. Bayer, R. Bechini, T. Belenguer, R. Bellotti, K. Belov, A. A. Berlind, M. Bertaina, P. L. Biermann, S. Biktemerova, C. Blaksley, N. Blanc, J. Blecki, S. Blin-Bondil, J. Bluemer, P. Bobik, M. Bogomilov, M. Bonamente, M. S. Briggs, S. Briz, A. Bruno, F. Cafagna, D. Campana, J-N. Capdevielle, R. Caruso, M. Casolino, C. Cassardo, G. Castellini, C. Catalano, O. Catalano, A. Cellino, M. Chikawa, M. J. Christl, D. Cline, V. Connaughton, L. Conti, G. Cordero, H. J. Crawford, R. Cremonini, S. Csorna, S. Dagoret-Campagne, A. J. de Castro, C. de Donato, C. de la Taille, C. de Santis, L. del Peral, A. Dell'Oro, N. De Simone, M. Di Martino, G. Distratis, F. Dulucq, M. Dupieux, A. Ebersoldt, T. Ebisuzaki, R. Engel, S. Falk, K. Fang, F. Fenu, I. Fernandez-Gomez, S. Ferrarese, D. Finco, M. Flamini, C. Fornaro, A. Franceschi, J. Fujimoto, M. Fukushima, P. Galeotti, G. Garipov, J. Geary, G. Gelmini, G. Giraudo, M. Gonchar, C. Gonzalez Alvarado, P. Gorodetzky, F. Guarino, A. Guzman, Y. Hachisu, B. Harlov, A. Haungs, J. Hernandez Carretero, K. Higashide, D. Ikeda, H. Ikeda, N. Inoue, S. Inoue, A. Insolia, F. Isgro, Y. Itow, E. Joven, E. G. Judd, A. Jung, F. Kajino, T. Kajino, I. Kaneko, Y. Karadzhov, J. Karczmarczyk, M. Karus, K. Katahira, K. Kawai, Y. Kawasaki, B. Keilhauer, B. A. Khrenov, Jeong-Sook Kim, Soon-Wook Kim, Sug-Whan Kim, M. Kleifges, P. A. Klimov, D. Kolev, I. Kreykenbohm, K. Kudela, Y. Kurihara, A. Kusenko, E. Kuznetsov, M. Lacombe, C. Lachaud, J. Lee, J. Licandro, H. Lim, F. Lopez, M. C. Maccarone, K. Mannheim, D. Maravilla, L. Marcelli, A. Marini, O. Martinez, G. Masciantonio, K. Mase, R. Matev, G. Medina-Tanco, T. Mernik, H. Miyamoto, Y. Miyazaki, Y. Mizumoto, G. Modestino, A. Monaco, D. Monnier-Ragaigne, J. A. Morales de los Rios, C. Moretto, V. S. Morozenko, B. Mot, T. Murakami, M. Nagano, M. Nagata, S. Nagataki, T. Nakamura, T. Napolitano, D. Naumov, R. Nava, A. Neronov, K. Nomoto, T. Nonaka, T. Ogawa, S. Ogio, H. Ohmori, A. V. Olinto, P. Orleanski, G. Osteria, M. I. Panasyuk, E. Parizot, I. H. Park, H. W. Park, B. Pastircak, T. Patzak, T. Paul, C. Pennypacker, S. Perez Cano, T. Peter, P. Picozza, T. Pierog, L. W. Piotrowski, S. Piraino, Z. Plebaniak, A. Pollini, P. Prat, G. Prevot, T. Pierog, L. W. Piotrowski, S. Piraino, Z. Plebaniak, A. Pollini, P. Prat, G. Prevot, H. Prieto, M. Putis, P. Reardon, M. Reyes, M. Ricci, I. Rodriguez, M. D. Rodriguez, M. D. Rodriguez Frias, F. Ronga, M. Roth, H. Rothkaehl, G. Roudil, I. Rusinov, M. Rybczynski, M. D. Sabau, G. Saez Cano, H. Sagawa, A. Saito, N. Sakaki, M. Sakata, H. Salazar, S. Sanchez, A. Santangelo, L. Santiago Cruz, M. Sanz Palomino, O. Saprykin, F. Sarazin, H. Sato, M. Sato, T. Schanz, H. Schieler, V. Scotti, A. Segreto, S. Selmane, D. Semikoz, M. Serra, S. Sharakin, T. Shibata, H. M. Shimizu, K. Shinozaki, T. Shirahama, G. Siemieniec-Ozieblo, H. H. Silva Lopez, J. Sledd, K. Slominska, A. Sobey, T. Sugiyama, D. Supanitsky, M. Suzuki, B. Szabelska, J. Szabelski, F. Tajima, N. Tajima, T. Tajima, Y. Takahashi, H. Takami, M. Takeda, Y. Takizawa, C. Tenzer, O. Tibolla, L. Tkachev, H. Tokuno, T. Tomida, N. Tone, S. Toscano, F. Trillaud, R. Tsenov, Y. Tsunesada, K. Tsuno, T. Tymieniecka, Y. Uchihori, M. Unger, O. Vaduvescu, J. F. Valdes-Galicia, P. Vallania, L. Valore, G. Vankova, C. Vigorito, L. Villasenor, P. von Ballmoos, S. Wada, J. Watanabe, S. Watanabe, J. Watts, M. Weber, T. J. Weiler, T. Wibig, L. Wiencke, M. Wille, J. Wilms, Z. Wlodarczyk, T. Yamamoto, Y. Yamamoto, J. Yang, H. Yano, I. V. Yashin, D. Yonetoku, K. Yoshida, S. Yoshida, R. Young, M. Yu. Zotov, A. Zuccaro Marchi
EXPERIMENTAL ASTRONOMY, 40, 1, 91, 116, SPRINGER, Nov. 2015, [Peer-reviewed]
English, Scientific journal, The JEM-EUSO telescope will be, after calibration, a very accurate instrument which yields the number of received photons from the number of measured photo-electrons. The project is in phase A (demonstration of the concept) including already operating prototype instruments, i.e. many parts of the instrument have been constructed and tested. Calibration is a crucial part of the instrument and its use. The focal surface (FS) of the JEM-EUSO telescope will consist of about 5000 photo-multiplier tubes (PMTs), which have to be well calibrated to reach the required accuracy in reconstructing the air-shower parameters. The optics system consists of 3 plastic Fresnel (double-sided) lenses of 2.5 m diameter. The aim of the calibration system is to measure the efficiencies (transmittances) of the optics and absolute efficiencies of the entire focal surface detector. The system consists of 3 main components: (i) Pre-flight calibration devices on ground, where the efficiency and gain of the PMTs will be measured absolutely and also the transmittance of the optics will be. (ii) On-board relative calibration system applying two methods: a) operating during the day when the JEM-EUSO lid will be closed with small light sources on board. b) operating during the night, together with data taking: the monitoring of the background rate over identical sites. (iii) Absolute in-flight calibration, again, applying two methods: a) measurement of the moon light, reflected on high altitude, high albedo clouds. b) measurements of calibrated flashes and tracks produced by the Global Light System (GLS). Some details of each calibration method will be described in this paper.

Performances of JEM-EUSO: energy and X (max) reconstruction
J. H. Adams, S. Ahmad, J. -N. Albert, D. Allard, L. Anchordoqui, V. Andreev, A. Anzalone, Y. Arai, K. Asano, M. Ave Pernas, P. Baragatti, P. Barrillon, T. Batsch, J. Bayer, R. Bechini, T. Belenguer, R. Bellotti, K. Belov, A. A. Berlind, M. Bertaina, P. L. Biermann, S. Biktemerova, C. Blaksley, N. Blanc, J. Blecki, S. Blin-Bondil, J. Bluemer, P. Bobik, M. Bogomilov, M. Bonamente, M. S. Briggs, S. Briz, A. Bruno, F. Cafagna, D. Campana, J-N. Capdevielle, R. Caruso, M. Casolino, C. Cassardo, G. Castellini, C. Catalano, O. Catalano, A. Cellino, M. Chikawa, M. J. Christl, D. Cline, V. Connaughton, L. Conti, G. Cordero, H. J. Crawford, R. Cremonini, S. Csorna, S. Dagoret-Campagne, A. J. de Castro, C. De Donato, C. de la Taille, C. De Santis, L. del Peral, A. Dell'Oro, N. De Simone, M. Di Martino, G. Distratis, F. Dulucq, M. Dupieux, A. Ebersoldt, T. Ebisuzaki, R. Engel, S. Falk, K. Fang, F. Fenu, I. Fernandez-Gomez, S. Ferrarese, D. Finco, M. Flamini, C. Fornaro, A. Franceschi, J. Fujimoto, M. Fukushima, P. Galeotti, G. Garipov, J. Geary, G. Gelmini, G. Giraudo, M. Gonchar, C. Gonzalez Alvarado, P. Gorodetzky, F. Guarino, A. Guzman, Y. Hachisu, B. Harlov, A. Haungs, J. Hernandez Carretero, K. Higashide, D. Ikeda, H. Ikeda, N. Inoue, S. Inoue, A. Insolia, F. Isgro, Y. Itow, E. Joven, E. G. Judd, A. Jung, F. Kajino, T. Kajino, I. Kaneko, Y. Karadzhov, J. Karczmarczyk, M. Karus, K. Katahira, K. Kawai, Y. Kawasaki, B. Keilhauer, B. A. Khrenov, Jeong-Sook Kim, Soon-Wook Kim, Sug-Whan Kim, M. Kleifges, P. A. Klimov, D. Kolev, I. Kreykenbohm, K. Kudela, Y. Kurihara, A. Kusenko, E. Kuznetsov, M. Lacombe, C. Lachaud, J. Lee, J. Licandro, H. Lim, F. Lopez, M. C. Maccarone, K. Mannheim, D. Maravilla, L. Marcelli, A. Marini, O. Martinez, G. Masciantonio, K. Mase, R. Matev, G. Medina-Tanco, T. Mernik, H. Miyamoto, Y. Miyazaki, Y. Mizumoto, G. Modestino, A. Monaco, D. Monnier-Ragaigne, J. A. Morales de Los Rios, C. Moretto, V. S. Morozenko, B. Mot, T. Murakami, M. Nagano, M. Nagata, S. Nagataki, T. Nakamura, T. Napolitano, D. Naumov, R. Nava, A. Neronov, K. Nomoto, T. Nonaka, T. Ogawa, S. Ogio, H. Ohmori, A. V. Olinto, P. Orleanski, G. Osteria, M. I. Panasyuk, E. Parizot, I. H. Park, H. W. Park, B. Pastircak, T. Patzak, T. Paul, C. Pennypacker, S. Perez Cano, T. Peter, P. Picozza, T. Pierog, L. W. Piotrowski, S. Piraino, Z. Plebaniak, A. Pollini, P. Prat, G. Prevot, H. Prieto, M. Putis, P. Reardon, M. Reyes, M. Ricci, I. Rodriguez, M. D. Rodriguez Frias, F. Ronga, M. Roth, H. Rothkaehl, G. Roudil, I. Rusinov, M. Rybczynski, M. D. Sabau, G. Saez Cano, H. Sagawa, A. Saito, N. Sakaki, M. Sakata, H. Salazar, S. Sanchez, A. Santangelo, L. Santiago Cruz, M. Sanz Palomino, O. Saprykin, F. Sarazin, H. Sato, M. Sato, T. Schanz, H. Schieler, V. Scotti, A. Segreto, S. Selmane, D. Semikoz, M. Serra, S. Sharakin, T. Shibata, H. M. Shimizu, K. Shinozaki, T. Shirahama, G. Siemieniec-Ozieblo, H. H. Silva Lopez, J. Sledd, K. Slominska, A. Sobey, T. Sugiyama, D. Supanitsky, M. Suzuki, B. Szabelska, J. Szabelski, F. Tajima, N. Tajima, T. Tajima, Y. Takahashi, H. Takami, M. Takeda, Y. Takizawa, C. Tenzer, O. Tibolla, L. Tkachev, H. Tokuno, T. Tomida, N. Tone, S. Toscano, F. Trillaud, R. Tsenov, Y. Tsunesada, K. Tsuno, T. Tymieniecka, Y. Uchihori, M. Unger, O. Vaduvescu, J. F. Valdes-Galicia, P. Vallania, L. Valore, G. Vankova, C. Vigorito, L. Villasenor, P. von Ballmoos, S. Wada, J. Watanabe, S. Watanabe, J. Watts, M. Weber, T. J. Weiler, T. Wibig, L. Wiencke, M. Wille, J. Wilms, Z. Wlodarczyk, T. Yamamoto, Y. Yamamoto, J. Yang, H. Yano, I. V. Yashin, D. Yonetoku, K. Yoshida, S. Yoshida, R. Young, M. Yu. Zotov
EXPERIMENTAL ASTRONOMY, 40, 1, 183, 214, SPRINGER, Nov. 2015, [Peer-reviewed]
English, Scientific journal, The Extreme Universe Space Observatory (EUSO) on-board the Japanese Experimental Module (JEM) of the International Space Station aims at the detection of ultra high energy cosmic rays from space. The mission consists of a UV telescope which will detect the fluorescence light emitted by cosmic ray showers in the atmosphere. The mission, currently developed by a large international collaboration, is designed to be launched within this decade. In this article, we present the reconstruction of the energy of the observed events and we also address the X (max) reconstruction. After discussing the algorithms developed for the energy and X (max) reconstruction, we present several estimates of the energy resolution, as a function of the incident angle, and energy of the event. Similarly, estimates of the X (max) resolution for various conditions are presented.

The infrared camera onboard JEM-EUSO
J. H. Adams, S. Ahmad, J. -N. Albert, D. Allard, L. Anchordoqui, V. Andreev, A. Anzalone, Y. Arai, K. Asano, M. Ave Pernas, P. Baragatti, P. Barrillon, T. Batsch, J. Bayer, R. Bechini, T. Belenguer, R. Bellotti, K. Belov, A. A. Berlind, M. Bertaina, P. L. Biermann, S. Biktemerova, C. Blaksley, N. Blanc, J. Blecki, S. Blin-Bondil, J. Bluemer, P. Bobik, M. Bogomilov, M. Bonamente, M. S. Briggs, S. Briz, A. Bruno, F. Cafagna, D. Campana, J-N. Capdevielle, R. Caruso, M. Casolino, C. Cassardo, G. Castellini, C. Catalano, O. Catalano, A. Cellino, M. Chikawa, M. J. Christl, D. Cline, V. Connaughton, L. Conti, G. Cordero, H. J. Crawford, R. Cremonini, S. Csorna, S. Dagoret-Campagne, A. J. de Castro, C. De Donato, C. de la Taille, C. De Santis, L. del Peral, A. Dell'Oro, N. De Simone, M. Di Martino, G. Distratis, F. Dulucq, M. Dupieux, A. Ebersoldt, T. Ebisuzaki, R. Engel, S. Falk, K. Fang, F. Fenu, I. Fernandez-Gomez, S. Ferrarese, D. Finco, M. Flamini, C. Fornaro, A. Franceschi, J. Fujimoto, M. Fukushima, P. Galeotti, G. Garipov, J. Geary, G. Gelmini, G. Giraudo, M. Gonchar, C. Gonzalez Alvarado, P. Gorodetzky, F. Guarino, A. Guzman, Y. Hachisu, B. Harlov, A. Haungs, J. Hernandez Carretero, K. Higashide, D. Ikeda, H. Ikeda, N. Inoue, S. Inoue, A. Insolia, F. Isgro, Y. Itow, E. Joven, E. G. Judd, A. Jung, F. Kajino, T. Kajino, I. Kaneko, Y. Karadzhov, J. Karczmarczyk, M. Karus, K. Katahira, K. Kawai, Y. Kawasaki, B. Keilhauer, B. A. Khrenov, Jeong-Sook Kim, Soon-Wook Kim, Sug-Whan Kim, M. Kleifges, P. A. Klimov, D. Kolev, I. Kreykenbohm, K. Kudela, Y. Kurihara, A. Kusenko, E. Kuznetsov, M. Lacombe, C. Lachaud, J. Lee, J. Licandro, H. Lim, F. Lopez, M. C. Maccarone, K. Mannheim, D. Maravilla, L. Marcelli, A. Marini, O. Martinez, G. Masciantonio, K. Mase, R. Matev, G. Medina-Tanco, T. Mernik, H. Miyamoto, Y. Miyazaki, Y. Mizumoto, G. Modestino, A. Monaco, D. Monnier-Ragaigne, J. A. Morales de los Rios, C. Moretto, V. S. Morozenko, B. Mot, T. Murakami, M. Nagano, M. Nagata, S. Nagataki, T. Nakamura, T. Napolitano, D. Naumov, R. Nava, A. Neronov, K. Nomoto, T. Nonaka, T. Ogawa, S. Ogio, H. Ohmori, A. V. Olinto, P. Orleanski, G. Osteria, M. I. Panasyuk, E. Parizot, I. H. Park, H. W. Park, B. Pastircak, T. Patzak, T. Paul, C. Pennypacker, S. Perez Cano, T. Peter, P. Picozza, T. Pierog, L. W. Piotrowski, S. Piraino, Z. Plebaniak, A. Pollini, P. Prat, G. Prevot, H. Prieto, M. Putis, P. Reardon, M. Reyes, M. Ricci, I. Rodriguez, M. D. Rodriguez Frias, F. Ronga, M. Roth, H. Rothkaehl, G. Roudil, I. Rusinov, M. Rybczynski, M. D. Sabau, G. Saez Cano, H. Sagawa, A. Saito, N. Sakaki, M. Sakata, H. Salazar, S. Sanchez, A. Santangelo, L. Santiago Cruz, M. Sanz Palomino, O. Saprykin, F. Sarazin, H. Sato, M. Sato, T. Schanz, H. Schieler, V. Scotti, A. Segreto, S. Selmane, D. Semikoz, M. Serra, S. Sharakin, T. Shibata, H. M. Shimizu, K. Shinozaki, T. Shirahama, G. Siemieniec-Ozieblo, H. H. Silva Lopez, J. Sledd, K. Slominska, A. Sobey, T. Sugiyama, D. Supanitsky, M. Suzuki, B. Szabelska, J. Szabelski, F. Tajima, N. Tajima, T. Tajima, Y. Takahashi, H. Takami, M. Takeda, Y. Takizawa, C. Tenzer, O. Tibolla, L. Tkachev, H. Tokuno, T. Tomida, N. Tone, S. Toscano, F. Trillaud, R. Tsenov, Y. Tsunesada, K. Tsuno, T. Tymieniecka, Y. Uchihori, M. Unger, O. Vaduvescu, J. F. Valdes-Galicia, P. Vallania, L. Valore, G. Vankova, C. Vigorito, L. Villasenor, P. von Ballmoos, S. Wada, J. Watanabe, S. Watanabe, J. Watts, M. Weber, T. J. Weiler, T. Wibig, L. Wiencke, M. Wille, J. Wilms, Z. Wlodarczyk, T. Yamamoto, Y. Yamamoto, J. Yang, H. Yano, I. V. Yashini, D. Yonetoku, K. Yoshida, S. Yoshida, R. Young, M. Yu. Zotovi, A. Zuccaro Marchi
EXPERIMENTAL ASTRONOMY, 40, 1, 61, 89, SPRINGER, Nov. 2015, [Peer-reviewed]
English, Scientific journal, The Extreme Universe Space Observatory on the Japanese Experiment Module (JEM-EUSO) on board the International Space Station (ISS) is the first space-based mission worldwide in the field of Ultra High-Energy Cosmic Rays (UHECR). For UHECR experiments, the atmosphere is not only the showering calorimeter for the primary cosmic rays, it is an essential part of the readout system, as well. Moreover, the atmosphere must be calibrated and has to be considered as input for the analysis of the fluorescence signals. Therefore, the JEM-EUSO Space Observatory is implementing an Atmospheric Monitoring System (AMS) that will include an IR-Camera and a LIDAR. The AMS Infrared Camera is an infrared, wide FoV, imaging system designed to provide the cloud coverage along the JEM-EUSO track and the cloud top height to properly achieve the UHECR reconstruction in cloudy conditions. In this paper, an updated preliminary design status, the results from the calibration tests of the first prototype, the simulation of the instrument, and preliminary cloud top height retrieval algorithms are presented.

The JEM-EUSO observation in cloudy conditions
J. H. Adams, S. Ahmad, J. -N. Albert, D. Allard, L. Anchordoqui, V. Andreev, A. Anzalone, Y. Arai, K. Asano, M. Ave Pernas, P. Baragatti, P. Barrillon, T. Batsch, J. Bayer, R. Bechini, T. Belenguer, R. Bellotti, K. Belov, A. A. Berlind, M. Bertaina, P. L. Biermann, S. Biktemerova, C. Blaksley, N. Blanc, J. Blecki, S. Blin-Bondil, J. Bluemer, P. Bobik, M. Bogomilov, M. Bonamente, M. S. Briggs, S. Briz, A. Bruno, F. Cafagna, D. Campana, J-N. Capdevielle, R. Caruso, M. Casolino, C. Cassardo, G. Castellini, C. Catalano, O. Catalano, A. Cellino, M. Chikawa, M. J. Christl, D. Cline, V. Connaughton, L. Conti, G. Cordero, H. J. Crawford, R. Cremonini, S. Csorna, S. Dagoret-Campagne, A. J. de Castro, C. De Donato, C. de la Taille, C. De Santis, L. del Peral, A. Dell'Oro, N. De Simone, M. Di Martino, G. Distratis, F. Dulucq, M. Dupieux, A. Ebersoldt, T. Ebisuzaki, R. Engel, S. Falk, K. Fang, F. Fenu, I. Fernandez-Gomez, S. Ferrarese, D. Finco, M. Flamini, C. Fornarodo, A. Franceschi, J. Fujimoto, M. Fukushima, P. Galeotti, G. Garipov, J. Geary, G. Gelmini, G. Giraudo, M. Gonchar, C. Gonzalez Alvarado, P. Gorodetzky, F. Guarino, A. Guzman, Y. Hachisu, B. Harlov, A. Haungs, J. Hernandez Carretero, K. Higashide, D. Ikeda, H. Ikeda, N. Inoue, S. Inoue, A. Insolia, F. Isgro, Y. Itow, E. Joven, E. G. Judd, A. Jung, F. Kajino, T. Kajino, I. Kaneko, Y. Karadzhov, J. Karczmarczyk, M. Karus, K. Katahira, K. Kawai, Y. Kawasaki, B. Keilhauer, B. A. Khrenov, Jeong-Sook Kim, Soon-Wook Kim, Sug-Whan Kim, M. Kleifges, P. A. Klimov, D. Kolev, I. Kreykenbohm, K. Kudela, Y. Kurihara, A. Kusenko, E. Kuznetsov, M. Lacombe, C. Lachaud, J. Lee, J. Licandro, H. Lim, F. Lopez, M. C. Maccarone, K. Mannheim, D. Maravilla, L. Marcelli, A. Marini, O. Martinez, G. Masciantonio, K. Mase, R. Matev, G. Medina-Tanco, T. Mernik, H. Miyamoto, Y. Miyazaki, Y. Mizumoto, G. Modestino, A. Monaco, D. Monnier-Ragaigne, J. A. Morales de los Rios, C. Moretto, V. S. Morozenko, B. Mot, T. Murakami, M. Nagano, M. Nagata, S. Nagataki, T. Nakamura, T. Napolitano, D. Naumov, R. Nava, A. Neronov, K. Nomoto, T. Nonaka, T. Ogawa, S. Ogio, H. Ohmori, A. V. Olinto, P. Orleanski, G. Osteria, M. I. Panasyuk, E. Parizot, I. H. Park, H. W. Park, B. Pastircakja, T. Patzak, T. Paul, C. Pennypacker, S. Perez Cano, T. Peter, P. Picozza, T. Pierog, L. W. Piotrowski, S. Piraino, Z. Plebaniak, A. Pollini, P. Prat, G. Prevot, H. Prieto, M. Putis, P. Reardon, M. Reyes, M. Ricci, I. Rodriguez, M. D. Rodriguez Frias, F. Ronga, M. Roth, H. Rothkaehl, G. Roudil, I. Rusinov, M. Rybczynski, M. D. Sabau, G. Saez Cano, H. Sagawa, A. Saito, N. Sakaki, M. Sakata, H. Salazar, S. Sanchez, A. Santangelo, L. Santiago Cruz, M. Sanz Palomino, O. Saprykin, F. Sarazin, H. Sato, M. Sato, T. Schanz, H. Schieler, V. Scotti, A. Segreto, S. Selmane, D. Semikoz, M. Serra, S. Sharakin, T. Shibata, H. M. Shimizu, K. Shinozaki, T. Shirahama, G. Siemieniec-Ozieblo, H. H. Silva Lopez, J. Sledd, K. Slominska, A. Sobey, T. Sugiyama, D. Supanitsky, M. Suzuki, B. Szabelska, J. Szabelski, F. Tajima, N. Tajima, T. Tajima, Y. Takahashi, H. Takami, M. Takeda, Y. Takizawa, C. Tenzer, O. Tibolla, L. Tkachev, H. Tokuno, T. Tomida, N. Tone, S. Toscano, F. Trillaud, R. Tsenov, Y. Tsunesada, K. Tsuno, T. Tymieniecka, Y. Uchihori, M. Unger, O. Vaduvescu, J. F. Valdes-Galicia, P. Vallania, L. Valore, G. Vankova, C. Vigorito, L. Villasenor, P. von Ballmoos, S. Wada, J. Watanabe, S. Watanabe, J. Watts, M. Weber, T. J. Weiler, T. Wibig, L. Wiencke, M. Wille, J. Wilms, Z. Wlodarczyk, T. Yamamoto, Y. Yamamoto, J. Yang, H. Yano, I. V. Yashin, D. Yonetoku, K. Yoshida, S. Yoshida, R. Young, M. Yu. Zotov, A. Zuccaro Marchi
EXPERIMENTAL ASTRONOMY, 40, 1, 135, 152, SPRINGER, Nov. 2015, [Peer-reviewed]
English, Scientific journal, The JEM-EUSO (Extreme Universe Space Observatory on-board the Japanese Experiment Module) mission will conduct extensive air shower (EAS) observations on the International Space Station (ISS). Following the ISS orbit, JEM-EUSO will experience continuous changes in the atmospheric conditions, including cloud presence. The influence of clouds on space-based observation is, therefore, an important topic to investigate from both EAS property and cloud climatology points of view. In the present work, the impact of clouds on the apparent profile of EAS is demonstrated through the simulation studies, taking into account the JEM-EUSO instrument and properties of the clouds. These results show a dependence on the cloud-top altitude and optical depth of the cloud. The analyses of satellite measurements on the cloud distribution indicate that more than 60 % of the cases allow for conventional EAS observation, and an additional similar to 20 % with reduced quality. The combination of the relevant factors results in an effective trigger aperture of EAS observation similar to 72 %, compared to the one in the clear atmosphere condition.

The EUSO-Balloon pathfinder
J. H. Adams, S. Ahmad, J. -N. Albert, D. Allard, L. Anchordoqui, V. Andreev, A. Anzalone, Y. Arai, K. Asano, M. Ave Pernas, P. Barrillon, T. Batsch, J. Bayer, R. Bechini, T. Belenguer, R. Bellotti, K. Belov, A. A. Berlind, M. Bertaina, P. L. Biermann, S. Biktemerova, C. Blaksley, N. Blanc, J. Blecki, S. Blin-Bondil, J. Bluemer, P. Bobik, M. Bogomilov, M. Bonamente, M. S. Briggs, S. Briz, A. Bruno, F. Cafagna, D. Campana, J-N. Capdevielle, R. Caruso, M. Casolino, C. Cassardo, G. Castellini, C. Catalano, O. Catalano, A. Cellino, M. Chikawa, M. J. Christl, D. Cline, V. Connaughton, L. Conti, G. Cordero, H. J. Crawford, R. Cremonini, S. Csorna, S. Dagoret-Campagne, A. J. de Castro, C. De Donato, C. de la Taille, C. De Santis, L. del Peral, A. Dell'Oro, N. De Simone, M. Di Martino, G. Distratis, F. Dulucq, M. Dupieux, A. Ebersoldt, T. Ebisuzaki, R. Engel, S. Falk, K. Fang, F. Fenu, I. Fernandez-Gomez, S. Ferrarese, D. Finco, M. Flamini, C. Fornaro, A. Franceschi, J. Fujimoto, M. Fukushima, P. Galeotti, G. Garipov, J. Geary, G. Gelmini, G. Giraudo, M. Gonchari, C. Gonzalez Alvarado, P. Gorodetzky, F. Guarino, A. Guzman, Y. Hachisu, B. Harlov, A. Haungs, K. Higashide, D. Ikeda, H. Ikeda, N. Inoue, S. Inoue, A. Insolia, F. Isgro, Y. Itowen, E. Joven, E. G. Judd, A. Jung, F. Kajino, T. Kajino, I. Kaneko, Y. Karadzhov, J. Karczmarczyk, M. Karus, K. Katahira, K. Kawai, Y. Kawasaki, B. Keilhauer, B. A. Khrenov, Jeong-Sook Kim, Soon-Wook Kim, Sug-Whan Kim, M. Kleifges, P. A. Klimov, D. Kolev, I. Kreykenbohm, K. Kudela, Y. Kurihara, A. Kusenko, E. Kuznetsov, M. Lacombe, C. Lachaud, J. Lee, J. Licandro, H. Lim, F. Lopez, M. C. Maccarone, K. Mannheim, D. Maravilla, L. Marcelli, A. Marini, O. Martinez, G. Masciantonio, K. Mase, R. Matev, G. Medina-Tanco, T. Mernik, H. Miyamoto, Y. Miyazaki, Y. Mizumoto, G. Modestino, A. Monaco, D. Monnier-Ragaigne, J. A. Morales de los Rios, C. Moretto, V. S. Morozenko, B. Mot, T. Murakami, M. Nagano, M. Nagata, S. Nagataki, T. Nakamura, T. Napolitano, D. Naumov, R. Nava, A. Neronov, K. Nomoto, T. Nonaka, T. Ogawa, S. Ogio, H. Ohmori, A. V. Olinto, P. Orleanski, G. Osteria, M. I. Panasyuk, E. Parizot, I. H. Park, H. W. Park, B. Pastircak, T. Patzak, T. Paul, C. Pennypacker, S. Perez Cano, T. Peter, P. Picozza, T. Pierog, L. W. Piotrowski, S. Piraino, Z. Plebaniak, A. Pollini, P. Prat, G. Prevot, H. Prieto, M. Putis, P. Reardon, M. Reyes, M. Ricci, I. Rodriguez, M. D. Rodriguez Frias, F. Ronga, M. Roth, H. Rothkaehl, G. Roudil, I. Rusinov, M. Rybczynski, M. D. Sabau, G. Saez Cano, H. Sagawa, A. Saito, N. Sakaki, M. Sakata, H. Salazar, S. Sanchez, A. Santangelo, L. Santiago Cruz, M. Sanz Palomino, O. Saprykin, F. Sarazin, H. Sato, M. Sato, T. Schanz, H. Schieler, V. Scotti, A. Segreto, S. Selmane, D. Semikoz, M. Serra, S. Sharakin, T. Shibata, H. M. Shimizu, K. Shinozaki, T. Shirahama, G. Siemieniec-Ozieblo, H. H. Silva Lopez, J. Sledd, K. Slominska, A. Sobey, T. Sugiyama, D. Supanitsky, M. Suzuki, B. Szabelska, J. Szabelski, F. Tajima, N. Tajima, T. Tajima, Y. Takahashi, H. Takami, M. Takeda, Y. Takizawa, C. Tenzer, O. Tibolla, L. Tkachev, H. Tokuno, T. Tomida, N. Tone, S. Toscano, F. Trillaud, R. Tsenov, Y. Tsunesada, K. Tsuno, T. Tymieniecka, Y. Uchihori, M. Unger, O. Vaduvescu, J. F. Valdes-Galicia, P. Vallania, L. Valore, G. Vankova, C. Vigorito, L. Villasenor, P. von Ballmoos, S. Wada, J. Watanabe, S. Watanabe, J. Watts, M. Weber, T. J. Weiler, T. Wibig, L. Wiencke, M. Wille, J. Wilms, Z. Wl Odarczyk, T. Yamamoto, Y. Yamamoto, J. Yang, H. Yano, I. V. Yashin, D. Yonetoku, K. Yoshida, S. Yoshida, R. Young, M. Yu. Zotov, A. Zuccaro Marchi
EXPERIMENTAL ASTRONOMY, 40, 1, 281, 299, SPRINGER, Nov. 2015, [Peer-reviewed]
English, Scientific journal, EUSO-Balloon is a pathfinder for JEM-EUSO, the Extreme Universe Space Observatory which is to be hosted on-board the International Space Station. As JEM-EUSO is designed to observe Ultra-High Energy Cosmic Rays (UHECR)-induced Extensive Air Showers (EAS) by detecting their ultraviolet light tracks "from above", EUSO-Balloon is a nadir-pointing UV telescope too. With its Fresnel Optics and Photo-Detector Module, the instrument monitors a 50 km(2) ground surface area in a wavelength band of 290-430 nm, collecting series of images at a rate of 400,000 frames/sec. The objectives of the balloon demonstrator are threefold: a) perform a full end-to-end test of a JEM-EUSO prototype consisting of all the main subsystems of the space experiment, b) measure the effective terrestrial UV background, with a spatial and temporal resolution relevant for JEM-EUSO. c) detect tracks of ultraviolet light from near space for the first time. The latter is a milestone in the development of UHECR science, paving the way for any future space-based UHECR observatory. On August 25, 2014, EUSO-Balloon was launched from Timmins Stratospheric Balloon Base (Ontario, Canada) by the balloon division of the French Space Agency CNES. From a float altitude of 38 km, the instrument operated during the entire astronomical night, observing UV-light from a variety of ground-covers and from hundreds of simulated EASs, produced by flashers and a laser during a two-hour helicopter under-flight.

The JEM-EUSO mission: An introduction
J. H. Adams, S. Ahmad, J. -N. Albert, D. Allard, L. Anchordoqui, V. Andreev, A. Anzalone, Y. Arai, K. Asano, M. Ave Pernas, P. Baragatti, P. Barrillon, T. Batsch, J. Bayer, R. Bechini, T. Belenguer, R. Bellotti, K. Belov, A. A. Berlind, M. Bertaina, P. L. Biermann, S. Biktemerova, C. Blaksley, N. Blanc, J. Blecki, S. Blin-Bondil, J. Bluemer, P. Bobik, M. Bogomilov, M. Bonamente, M. S. Briggs, S. Briz, A. Bruno, F. Cafagna, D. Campana, J-N. Capdevielle, R. Caruso, M. Casolino, C. Cassardo, G. Castellini, C. Catalano, O. Catalano, A. Cellino, M. Chikawa, M. J. Christl, D. Cline, V. Connaughton, L. Conti, G. Cordero, H. J. Crawford, R. Cremonini, S. Csorna, S. Dagoret-Campagne, A. J. de Castro, C. de Donato, C. de la Taille, C. de Santis, L. del Peral, A. Dell'Oro, N. De Simone, M. Di Martino, G. Distratis, F. Dulucq, M. Dupieux, A. Ebersoldt, T. Ebisuzaki, R. Engel, S. Falk, K. Fang, F. Fenu, I. Fernandez-Gomez, S. Ferrarese, D. Finco, M. Flamini, C. Fornaro, A. Franceschi, J. Fujimoto, M. Fukushima, P. Galeotti, G. Garipov, J. Geary, G. Gelmini, G. Giraudo, M. Gonchar, C. Gonzalez Alvarado, P. Gorodetzky, F. Guarino, A. Guzman, Y. Hachisu, B. Harlov, A. Haungs, J. Hernandez Carretero, K. Higashide, D. Ikeda, H. Ikeda, N. Inoue, S. Inoue, A. Insolia, F. Isgro, Y. Itow, E. Joven, E. G. Judd, A. Jung, F. Kajino, T. Kajino, I. Kaneko, Y. Karadzhov, J. Karczmarczyk, M. Karus, K. Katahira, K. Kawai, Y. Kawasaki, B. Keilhauer, B. A. Khrenov, Jeong-Sook Kim, Soon-Wook Kim, Sug-Whan Kim, M. Kleifges, P. A. Klimov, D. Kolev, I. Kreykenbohm, K. Kudela, Y. Kurihara, A. Kusenko, E. Kuznetsov, M. Lacombe, C. Lachaud, J. Lee, J. Licandro, H. Lim, F. Lopez, M. C. Maccarone, K. Mannheim, D. Maravilla, L. Marcelli, A. Marini, O. Martinez, G. Masciantonio, K. Mase, R. Matev, G. Medina-Tanco, T. Mernik, H. Miyamoto, Y. Miyazaki, Y. Mizumoto, G. Modestino, A. Monaco, D. Monnier-Ragaigne, J. A. Morales de Los Rios, C. Moretto, V. S. Morozenko, B. Mot, T. Murakami, M. Nagano, M. Nagata, S. Nagataki, T. Nakamura, T. Napolitano, D. Naumov, R. Nava, A. Neronov, K. Nomoto, T. Nonaka, T. Ogawa, S. Ogio, H. Ohmori, A. V. Olinto, P. Orleanski, G. Osteria, M. I. Panasyuk, E. Parizot, I. H. Park, H. W. Park, B. Pastircak, T. Patzak, T. Paul, C. Pennypacker, S. Perez Cano, T. Peter, P. Picozza, T. Pierog, L. W. Piotrowski, S. Piraino, Z. Plebaniak, A. Pollini, P. Prat, G. Prevot, H. Prieto, M. Putis, P. Reardon, M. Reyes, M. Ricci, I. Rodriguez, M. D. Rodriguez Frias, F. Ronga, M. Roth, H. Rothkaehl, G. Roudil, I. Rusinov, M. Rybczynski, M. D. Sabau, G. Saez Cano, H. Sagawa, A. Saito, N. Sakaki, M. Sakata, H. Salazar, S. Sanchez, A. Santangelo, L. Santiago Cruz, M. Sanz Palomino, O. Saprykin, F. Sarazin, H. Sato, M. Sato, T. Schanz, H. Schieler, V. Scotti, A. Segreto, S. Selmane, D. Semikoz, M. Serra, S. Sharakin, T. Shibata, H. M. Shimizu, K. Shinozaki, T. Shirahama, G. Siemieniec-Ozieblo, H. H. Silva Lopez, J. Sledd, K. Slominska, A. Sobey, T. Sugiyama, D. Supanitsky, M. Suzuki, B. Szabelska, J. Szabelski, F. Tajima, N. Tajima, T. Tajima, Y. Takahashi, H. Takami, M. Takeda, Y. Takizawa, C. Tenzer, O. Tibolla, L. Tkachev, H. Tokuno, T. Tomida, N. Tone, S. Toscano, F. Trillaud, R. Tsenov, Y. Tsunesada, K. Tsuno, T. Tymieniecka, Y. Uchihori, M. Unger, O. Vaduvescu, J. F. Valdes-Galicia, P. Vallania, L. Valore, G. Vankova, C. Vigorito, L. Villasenor, P. von Ballmoos, S. Wada, J. Watanabe, S. Watanabe, J. Watts, M. Weber, T. J. Weiler, T. Wibig, L. Wiencke, M. Wille, J. Wilms, Z. Wlodarczyk, T. Yamamoto, Y. Yamamoto, J. Yang, H. Yano, I. V. Yashin, D. Yonetoku, K. Yoshida, S. Yoshida, R. Young, M. Yu. Zotov, A. Zuccaro Marchi
EXPERIMENTAL ASTRONOMY, 40, 1, 3, 17, SPRINGER, Nov. 2015, [Peer-reviewed]
English, Scientific journal, The Extreme Universe Space Observatory on board the Japanese Experiment Module of the International Space Station, JEM-EUSO, is being designed to search from space ultra-high energy cosmic rays. These are charged particles with energies from a few 10(19) eV to beyond 10(20) eV, at the very end of the known cosmic ray energy spectrum. JEM-EUSO will also search for extreme energy neutrinos, photons, and exotic particles, providing a unique opportunity to explore largely unknown phenomena in our Universe. The mission, principally based on a wide field of view (60 degrees) near-UV telescope with a diameter of similar to 2.5 m, will monitor the earth's atmosphere at night, pioneering the observation from space of the ultraviolet tracks (290-430 nm) associated with giant extensive air showers produced by ultra-high energy primaries propagating in the earth's atmosphere. Observing from an orbital altitude of similar to 400 km, the mission is expected to reach an instantaneous geometrical aperture of A (g e o) a parts per thousand yen 2 x 10(5) km(2) sr with an estimated duty cycle of similar to 20 %. Such a geometrical aperture allows unprecedented exposures, significantly larger than can be obtained with ground-based experiments. In this paper we briefly review the history of space-based search for ultra-high energy cosmic rays. We then introduce the special issue of Experimental Astronomy devoted to the various aspects of such a challenging enterprise. We also summarise the activities of the on-going JEM-EUSO program.

Performances of JEM-EUSO: angular reconstruction (vol 30, pg 153, 2015)
J. H. Adams, S. Ahmad, J. -N. Albert, D. Allard, L. Anchordoqui, V. Andreev, A. Anzalone, Y. Arai, K. Asano, M. Ave Pernas, P. Baragatti, P. Barrillon, T. Batsch, J. Bayer, R. Bechini, T. Belenguer, R. Bellotti, K. Belov, A. A. Berlind, M. Bertaina, P. L. Biermann, S. Biktemerova, C. Blaksley, N. Blanc, J. Blecki, S. Blin-Bondil, J. Bluemer, P. Bobik, M. Bogomilov, M. Bonamente, M. S. Briggs, S. Briz, A. Bruno, F. Cafagna, D. Campana, J-N. Capdevielle, R. Caruso, M. Casolino, C. Cassardo, G. Castellini, C. Catalano, O. Catalano, A. Cellino, M. Chikawa, M. J. Christl, D. Cline, V. Connaughton, L. Conti, G. Cordero, H. J. Crawford, R. Cremonini, S. Csoma, S. Dagoret-Campagne, A. J. de Castro, C. De Donato, C. de la Taille, C. De Santis, L. del Peral, A. Dell'Oro, N. De Simone, M. Di Martino, G. Distratis, F. Dulucq, M. Dupieux, A. Ebersoldt, T. Ebisuzaki, R. Engel, S. Falk, K. Fang, F. Fenu, I. Fern'andez-G'omez, S. Ferrarese, D. Finco, M. Flamini, C. Fornaro, A. Franceschi, J. Fujimoto, M. Fukushima, P. Galeotti, G. Garipov, J. Geary, G. Gelmini, G. Giraudo, M. Gonchar, C. Gonz'alez Alvarado, P. Gorodetzky, F. Guarino, A. Guzman, Y. Hachisu, B. Harlov, A. Haungs, J. Hern'andez Carretero, K. Higashide, D. Ikeda, H. Ikeda, N. Inoue, S. Inoue, A. Insolia, F. Isgr'o, Y. Itow, E. Joven, E. G. Judd, A. Jung, F. Kajino, T. Kajino, I. Kaneko, Y. Karadzhov, J. Karczmarczyk, M. Karus, K. Katahira, K. Kawai, Y. Kawasaki, B. Keilhauer, B. A. Khrenov, Jeong-Sook Kim, Soon-Wook Kim, Sug-Whan Kim, M. Kleifges, P. A. Klimov, D. Kolev, I. Kreykenbohm, K. Kudela, Y. Kurihara, A. Kusenko, E. Kuznetsov, M. Lacombe, C. Lachaud, J. Lee, J. Licandro, H. Lim, F. L'opez, M. C. Maccarone, K. Mannheim, D. Maravilla, L. Marcelli, A. Marini, O. Martinez, G. Masciantonio, K. Mase, R. Matev, G. Medina-Tanco, T. Mernik, H. Miyamoto, Y. Miyazaki, Y. Mizumoto, G. Modestino, A. Monaco, D. Monnier-Ragaigne, J. A. Morales de los R'ios, C. Moretto, V. S. Morozenko, B. Mot, T. Murakami, M. Nagano, M. Nagata, S. Nagataki, T. Nakamura, T. Napolitano, D. Naumov, R. Nava, A. Neronov, K. Nomoto, T. Nonaka, T. Ogawa, S. Ogio, H. Ohmori, A. V. Olinto, P. Orlea'nski, G. Osteria, M. I. Panasyuk, E. Parizot, I. H. Park, H. W. Park, B. Pastircak, T. Patzak, T. Paul, C. Pennypacker, S. Perez Cano, T. Peter, P. Picozza, T. Pierog, L. W. Piotrowski, S. Piraino, Z. Plebaniak, A. Pollini, P. Prat, G. Pr'evot, H. Prieto, M. Putis, P. Reardon, M. Reyes, M. Ricci, I. Rodr'iguez, M. D. Rodr'iguez Fr'ias, F. Ronga, M. Roth, H. Rothkaehl, G. Roudil, I. Rusinov, M. Rybczy'nski, M. D. Sabau, G. S'aez Cano, H. Sagawa, A. Saito, N. Sakaki, M. Sakata, H. Salazar, S. S'anchez, A. Santangelo, L. Santiago Cr'uz, M. Sanz Palomino, O. Saprykin, F. Sarazin, H. Sato, M. Sato, T. Schanz, H. Schieler, V. Scotti, A. Segreto, S. Selmane, D. Semikoz, M. Serra, S. Sharakin, T. Shibata, H. M. Shimizu, K. Shinozaki, T. Shirahama, G. Siemieniec-Ozieblo, H. H. Silva L'opez, J. Sledd, K. Slomi'nska, A. Sobey, T. Sugiyama, D. Supanitsky, M. Suzuki, B. Szabelska, J. Szabelski, F. Tajima, N. Tajima, T. Tajima, Y. Takahashi, H. Takami, M. Takeda, Y. Takizawa, C. Tenzer, O. Tibolla, L. Tkachev, H. Tokuno, T. Tomida, N. Tone, S. Toscano, F. Trillaud, R. Tsenov, Y. Tsunesada, K. Tsuno, T. Tymieniecka, Y. Uchihori, M. Unger, O. Vaduvescu, J. F. Vald'es-Galicia, P. Vallania, L. Valore, G. Vankova, C. Vigorito, L. Villasenor, P. von Ballmoos, S. Wada, J. Watanabe, S. Watanabe, J. Watts, M. Weber, T. J. Weiler, T. Wibig, L. Wiencke, M. Wille, J. Wilms, Z. Wlodarczyk, T. Yamamoto, Y. Yamamoto, J. Yang, H. Yano, I. V. Yashin, D. Yonetoku, K. Yoshida, S. Yoshida, R. Young, M. Yu. Zotov
EXPERIMENTAL ASTRONOMY, 40, 1, 179, 181, SPRINGER, Nov. 2015, [Peer-reviewed]
English, Scientific journal

Science of atmospheric phenomena with JEM-EUSO
J. H. Adams, S. Ahmad, J. -N. Albert, D. Allard, L. Anchordoqui, V. Andreev, A. Anzalone, Y. Arai, K. Asano, M. Ave Pernas, P. Baragatti, P. Barrillon, T. Batsch, J. Bayer, R. Bechini, T. Belenguer, R. Bellotti, K. Belov, A. A. Berlind, M. Bertaina, P. L. Biermann, S. Biktemerova, C. Blaksley, N. Blanc, J. Blecki, S. Blin-Bondil, J. Bluemer, P. Bobik, M. Bogomilov, M. Bonamente, M. S. Briggs, S. Briz, A. Bruno, F. Cafagna, D. Campana, J-N. Capdevielle, R. Caruso, M. Casolino, C. Cassardo, G. Castellini, C. Catalano, O. Catalano, A. Cellino, M. Chikawa, M. J. Christl, D. Cline, V. Connaughton, L. Conti, G. Cordero, H. J. Crawford, R. Cremonini, S. Csorna, S. Dagoret-Campagne, A. J. de Castro, C. De Donato, C. de la Taille, C. De Santis, L. del Peral, A. Dell'Oro, N. De Simone, M. Di Martino, G. Distratis, F. Dulucq, M. Dupieux, A. Ebersoldt, T. Ebisuzaki, R. Engel, S. Falk, K. Fang, F. Fenu, I. Fernandez-Gomez, S. Ferrarese, D. Finco, M. Flamini, C. Fornaro, A. Franceschi, J. Fujimoto, M. Fukushima, P. Galeotti, G. Garipov, J. Geary, G. Gelmini, G. Giraudo, M. Gonchar, C. Gonzalez Alvarado, P. Gorodetzky, F. Guarino, A. Guzman, Y. Hachisu, B. Harlov, A. Haungs, J. Hernandez Carretero, K. Higashide, D. Ikeda, H. Ikeda, N. Inoue, S. Inoue, A. Insolia, F. Isgro, Y. Itow, E. Joven, E. G. Judd, A. Jung, F. Kajino, T. Kajino, I. Kaneko, Y. Karadzhov, J. Karczmarczyk, M. Karus, K. Katahira, K. Kawai, Y. Kawasaki, B. Keilhauer, B. A. Khrenov, Jeong-Sook Kim, Soon-Wook Kim, Sug-Whan Kim, M. Kleifges, P. A. Klimov, D. Kolev, I. Kreykenbohm, K. Kudela, Y. Kurihara, A. Kusenko, E. Kuznetsov, M. Lacombe, C. Lachaud, J. Lee, J. Licandro, H. Lim, F. Lopez, M. C. Maccarone, K. Mannheim, D. Maravilla, L. Marcelli, A. Marini, O. Martinez, G. Masciantonio, K. Mase, R. Matev, G. Medina-Tanco, T. Mernik, H. Miyamoto, Y. Miyazaki, Y. Mizumoto, G. Modestino, A. Monaco, D. Monnier-Ragaigne, J. A. Morales de los Rios, C. Moretto, V. S. Morozenko, B. Mot, T. Murakami, M. Nagano, M. Nagata, S. Nagataki, T. Nakamura, T. Napolitano, D. Naumov, R. Nava, A. Neronov, K. Nomoto, T. Nonaka, T. Ogawa, S. Ogio, H. Ohmori, A. V. Olinto, P. Orleanski, G. Osteria, M. I. Panasyuk, E. Parizot, I. H. Park, H. W. Park, B. Pastircak, T. Patzak, T. Paul, C. Pennypacker, S. Perez Cano, T. Peter, P. Picozza, T. Pierog, L. W. Piotrowski, S. Piraino, Z. Plebaniak, A. Pollini, P. Prat, G. Prevot, H. Prieto, M. Putis, P. Reardon, M. Reyes, M. Ricci, I. Rodriguez, M. D. Rodriguez Frias, F. Ronga, M. Roth, H. Rothkaehl, G. Roudil, I. Rusinov, M. Rybczynski, M. D. Sabau, G. Saez Cano, H. Sagawa, A. Saito, N. Sakaki, M. Sakata, H. Salazar, S. Sanchez, A. Santangelo, L. Santiago Cruz, M. Sanz Palomino, O. Saprykin, F. Sarazin, H. Sato, M. Sato, T. Schanz, H. Schieler, V. Scotti, A. Segreto, S. Selmane, D. Semikoz, M. Serra, S. Sharakin, T. Shibata, H. M. Shimizu, K. Shinozaki, T. Shirahama, G. Siemieniec-Ozieblo, H. H. Silva Lopez, J. Sledd, K. Slominska, A. Sobey, T. Sugiyama, D. Supanitsky, M. Suzuki, B. Szabelska, J. Szabelski, F. Tajima, N. Tajima, T. Tajima, Y. Takahashi, H. Takami, M. Takeda, Y. Takizawa, C. Tenzer, O. Tibolla, L. Tkachev, H. Tokuno, T. Tomida, N. Tone, S. Toscano, F. Trillaud, R. Tsenov, Y. Tsunesada, K. Tsuno, T. Tymieniecka, Y. Uchihori, M. Unger, O. Vaduvescu, J. F. Valdes-Galiciaga, P. Vallania, L. Valore, G. Vankova, C. Vigorito, L. Villasenor, P. von Ballmoos, S. Wada, J. Watanabe, S. Watanabe, J. Watts, M. Weber, T. J. Weiler, T. Wibig, L. Wiencke, M. Wille, J. Wilms, Z. Wlodarczyk, T. Yamamoto, Y. Yamamoto, J. Yang, H. Yano, I. V. Yashin, D. Yonetoku, K. Yoshida, S. Yoshida, R. Young, M. Yu. Zotov, A. Zuccaro Marchi
EXPERIMENTAL ASTRONOMY, 40, 1, 239, 251, SPRINGER, Nov. 2015, [Peer-reviewed]
English, Scientific journal, The main goal of the JEM-EUSO experiment is the study of Ultra High Energy Cosmic Rays (UHECR, 10(19)-10(21) e V), but the method which will be used (detection of the secondary light emissions induced by cosmic rays in the atmosphere) allows to study other luminous phenomena. The UHECRs will be detected through the measurement of the emission in the range between 290 and 430 m, where some part of Transient Luminous Events (TLEs) emission also appears. This work discusses the possibility of using the JEM-EUSO Telescope to get new scientific results on TLEs. The high time resolution of this instrument allows to observe the evolution of TLEs with great precision just at the moment of their origin. The paper consists of four parts: review of the present knowledge on the TLE, presentation of the results of the simulations of the TLE images in the JEM-EUSO telescope, results of the Russian experiment Tatiana-2 and discussion of the possible progress achievable in this field with JEM-EUSO as well as possible cooperation with other space projects devoted to the study of TLE - TARANIS and ASIM. In atmospheric physics, the study of TLEs became one of the main physical subjects of interest after their discovery in 1989. In the years 1992 - 1994 detection was performed from satellite, aircraft and space shuttle and recently from the International Space Station. These events have short duration (milliseconds) and small scales (km to tens of km) and appear at altitudes 50 - 100 km. Their nature is still not clear and each new experimental data can be useful for a better understanding of these mysterious phenomena.

The atmospheric monitoring system of the JEM-EUSO instrument
J. H. Adams, S. Ahmad, J. -N. Albert, D. Allard, L. Anchordoqui, V. Andreev, A. Anzalone, Y. Arai, K. Asano, M. Ave Pernas, P. Baragatti, P. Barrillon, T. Batsch, J. Bayer, R. Bechini, T. Belenguer, R. Bellotti, K. Belov, A. A. Berlind, M. Bertaina, P. L. Biermann, S. Biktemerova, C. Blaksley, N. Blanc, J. Blecki, S. Blin-Bondil, J. Bluemer, P. Bobik, M. Bogomilov, M. Bonamente, M. S. Briggs, S. Briz, A. Bruno, F. Cafagna, D. Campana, J-N. Capdevielle, R. Caruso, M. Casolino, C. Cassardo, G. Castellini, C. Catalano, O. Catalano, A. Cellino, M. Chikawa, M. J. Christl, D. Cline, V. Connaughton, L. Conti, G. Cordero, H. J. Crawford, R. Cremonini, S. Csorna, S. Dagoret-Campagne, A. J. de Castro, C. De Donato, C. de la Taille, C. De Santis, L. del Peral, A. Dell'Oro, N. De Simone, M. Di Martino, G. Distratis, F. Dulucq, M. Dupieux, A. Ebersoldt, T. Ebisuzaki, R. Engel, S. Falk, K. Fang, F. Fenu, I. Fernandez-Gomez, S. Ferrarese, D. Finco, M. Flamini, C. Fornaro, A. Franceschi, J. Fujimoto, M. Fukushima, P. Galeotti, G. Garipov, J. Geary, G. Gelmini, G. Giraudo, M. Gonchar, C. Gonzalez Alvarado, P. Gorodetzky, F. Guarino, A. Guzman, Y. Hachisu, B. Harlov, A. Haungs, J. Hernandez Carretero, K. Higashide, D. Ikeda, H. Ikeda, N. Inoue, S. Inoue, A. Insolia, F. Isgro, Y. Itow, E. Joven, E. G. Judd, A. Jung, F. Kajino, T. Kajino, I. Kaneko, Y. Karadzhov, J. Karczmarczyk, M. Karus, K. Katahira, K. Kawai, Y. Kawasaki, B. Keilhauer, B. A. Khrenov, Jeong-Sook Kim, Soon-Wook Kim, Sug-Whan Kim, M. Kleifges, P. A. Klimov, D. Kolev, I. Kreykenbohm, K. Kudela, Y. Kurihara, A. Kusenko, E. Kuznetsov, M. Lacombe, C. Lachaud, J. Lee, J. Licandro, H. Lim, F. Lopez, M. C. Maccarone, K. Mannheim, D. Maravilla, L. Marcelli, A. Marini, O. Martinez, G. Masciantonio, K. Mase, R. Matev, G. Medina-Tanco, T. Mernik, H. Miyamoto, Y. Miyazaki, Y. Mizumoto, G. Modestino, A. Monaco, D. Monnier-Ragaigne, J. A. Morales de los Rios, C. Moretto, V. S. Morozenko, B. Mot, T. Murakami, M. Nagano, M. Nagata, S. Nagataki, T. Nakamura, T. Napolitano, D. Naumov, R. Nava, A. Neronov, K. Nomoto, T. Nonaka, T. Ogawa, S. Ogio, H. Ohmori, A. V. Olinto, P. Orleanski, G. Osteria, M. I. Panasyuk, E. Parizot, I. H. Park, H. W. Park, B. Pastircak, T. Patzak, T. Paul, C. Pennypacker, S. Perez Cano, T. Peter, P. Picozza, T. Pierog, L. W. Piotrowski, S. Piraino, Z. Plebaniak, A. Pollini, P. Prat, G. Prevot, H. Prieto, M. Putis, P. Reardon, M. Reyes, M. Ricci, I. Rodriguez, M. D. Rodriguez Frias, F. Ronga, M. Roth, H. Rothkaehl, G. Roudil, I. Rusinov, M. Rybczynski, M. D. Sabau, G. Saez Cano, H. Sagawa, A. Saito, N. Sakaki, M. Sakata, H. Salazar, S. Sanchez, A. Santangelo, L. Santiago Cruz, M. Sanz Palomino, O. Saprykin, F. Sarazin, H. Sato, M. Sato, T. Schanz, H. Schieler, V. Scotti, A. Segreto, S. Selmane, D. Semikoz, M. Serra, S. Sharakin, T. Shibata, H. M. Shimizu, K. Shinozaki, T. Shirahama, G. Siemieniec-Ozieblo, H. H. Silva Lopez, J. Sledd, K. Slominska, A. Sobey, T. Sugiyama, D. Supanitsky, M. Suzuki, B. Szabelska, J. Szabelski, F. Tajima, N. Tajima, T. Tajima, Y. Takahashi, H. Takami, M. Takeda, Y. Takizawa, C. Tenzer, O. Tibolla, L. Tkachev, H. Tokuno, T. Tomida, N. Tone, S. Toscano, F. Trillaud, R. Tsenov, Y. Tsunesada, K. Tsuno, T. Tymieniecka, Y. Uchihori, M. Unger, O. Vaduvescu, J. F. Valdes-Galicia, P. Vallania, L. Valore, G. Vankova, C. Vigorito, L. Villasenor, P. von Ballmoos, S. Wada, J. Watanabe, S. Watanabe, J. Watts, M. Weber, J. Weiler, T. Wibig, L. Wiencke, M. Wille, J. Wilms, Z. Wlodarczyk, T. Yamamoto, Y. Yamamoto, J. Yang, H. Yano, I. V. Yashin, D. Yonetoku, K. Yoshida, S. Yoshida, R. Young, M. Yu. Zotov, A. Zuccaro Marchi
EXPERIMENTAL ASTRONOMY, 40, 1, 45, 60, SPRINGER, Nov. 2015, [Peer-reviewed]
English, Scientific journal, The JEM-EUSO telescope will detect Ultra-High Energy Cosmic Rays (UHECRs) from space, detecting the UV Fluorescence Light produced by Extensive Air Showers (EAS) induced by the interaction of the cosmic rays with the earth's atmosphere. The capability to reconstruct the properties of the primary cosmic ray depends on the accurate measurement of the atmospheric conditions in the region of EAS development. The Atmospheric Monitoring (AM) system of JEM-EUSO will host a LIDAR, operating in the UV band, and an Infrared camera to monitor the cloud cover in the JEM-EUSO Field of View, in order to be sensitive to clouds with an optical depth tau a parts per thousand yen 0.15 and to measure the cloud top altitude with an accuracy of 500 m and an altitude resolution of 500 m.

Ground-based measurements of the change in the propagation period of Y-feature on Venus
Imai, M, Takahashi, Y, Watanabe, S, Watanabe, M. an
European Planetary Science Congress, EPSC2015, 523, Oct. 2015
English, International conference proceedings

Overview and early results of the Global Lightning and Sprite Measurements mission
M. Sato, T. Ushio, T. Morimoto, M. Kikuchi, H. Kikuchi, T. Adachi, M. Suzuki, A. Yamazaki, Y. Takahashi, U. Inan, I. Linscott, R. Ishida, Y. Sakamoto, K. Yoshida, Y. Hobara, T. Sano, T. Abe, M. Nakamura, H. Oda, Z. -I. Kawasaki
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 120, 9, 3822, 3851, AMER GEOPHYSICAL UNION, May 2015, [Peer-reviewed]
English, Scientific journal, Global Lightning and Sprite Measurements on Japanese Experiment Module (JEM-GLIMS) is a space mission to conduct the nadir observations of lightning discharges and transient luminous events (TLEs). The main objectives of this mission are to identify the horizontal distribution of TLEs and to solve the occurrence conditions determining the spatial distribution. JEM-GLIMS was successfully launched and started continuous nadir observations in 2012. The global distribution of the detected lightning events shows that most of the events occurred over continental regions in the local summer hemisphere. In some events, strong far-ultraviolet emissions have been simultaneously detected with N-2 1P and 2P emissions by the spectrophotometers, which strongly suggest the occurrence of TLEs. Especially, in some of these events, no significant optical emission was measured by the narrowband filter camera, which suggests the occurrence of elves, not sprites. The VLF receiver also succeeded in detecting lightning whistlers, which show clear falling-tone frequency dispersion. Based on the optical data, the time delay from the detected lightning emission to the whistlers was identified as approximate to 10ms, which can be reasonably explained by the wave propagation with the group velocity of whistlers. The VHF interferometer conducted the spaceborne interferometric observations and succeeded in detecting VHF pulses. We observed that the VHF pulses are likely to be excited by the lightning discharge possibly related with in-cloud discharges and measured with the JEM-GLIMS optical instruments. Thus, JEM-GLIMS provides the first full set of optical and electromagnetic data of lightning and TLEs obtained by nadir observations from space.

Overview and early results of the global lightning and sprite measurements mission
M. Sato, T. Ushio, T. Morimoto, M. Kikuchi, H. Kikuchi, T. Adachi, M. Suzuki, A. Yamazaki, Y. Takahashi, U. Inan, I. Linscott, R. Ishida, Y. Sakamoto, K. Yoshida, Y. Hobara, T. Sano, T. Abe, M. Nakamura, H. Oda, Z. I. Kawasaki
Journal of Geophysical Research, 120, 9, 3822, 3851, 2015, [Peer-reviewed]
Scientific journal, © 2015. American Geophysical Union. All Rights Reserved. Global Lightning and Sprite Measurements on Japanese Experiment Module (JEM-GLIMS) is a space mission to conduct the nadir observations of lightning discharges and transient luminous events (TLEs). The main objectives of this mission are to identify the horizontal distribution of TLEs and to solve the occurrence conditions determining the spatial distribution. JEM-GLIMS was successfully launched and started continuous nadir observations in 2012. The global distribution of the detected lightning events shows that most of the events occurred over continental regions in the local summer hemisphere. In some events, strong far-ultraviolet emissions have been simultaneously detected with N2 1P and 2P emissions by the spectrophotometers, which strongly suggest the occurrence of TLEs. Especially, in some of these events, no significant optical emission was measured by the narrowband filter camera, which suggests the occurrence of elves, not sprites. The VLF receiver also succeeded in detecting lightning whistlers, which show clear falling-tone frequency dispersion. Based on the optical data, the time delay from the detected lightning emission to the whistlers was identified as ~10 ms, which can be reasonably explained by the wave propagation with the group velocity of whistlers. The VHF interferometer conducted the spaceborne interferometric observations and succeeded in detecting VHF pulses. We observed that the VHF pulses are likely to be excited by the lightning discharge possibly related with in-cloud discharges and measured with the JEM-GLIMS optical instruments. Thus, JEM-GLIMS provides the first full set of optical and electromagnetic data of lightning and TLEs obtained by nadir observations from space.

Return to venus of the Japanese venus climate orbiter AKATSUKI
Masato Nakamura, Yasuhiro Kawakatsu, Chikako Hirose, Takeshi Imamura, Nobuaki Ishii, Takumi Abe, Atsushi Yamazaki, Manabu Yamada, Kazunori Ogohara, Kazunori Uemizu, Tetsuya Fukuhara, Shoko Ohtsuki, Takehiko Satoh, Makoto Suzuki, Munetaka Ueno, Junichi Nakatsuka, Naomoto Iwagami, Makoto Taguchi, Shigeto Watanabe, Yukihiro Takahashi, George L. Hashimoto, Hiroki Yamamoto
Acta Astronautica, 93, 384, 389, 2014
Scientific journal, Japanese Venus Climate Orbiter/AKATSUKI was proposed in 2001 with strong support by international Venus science community and approved as an ISAS (The Institute of Space and Astronautical Science) mission soon after the proposal. The mission life we expected was more than two Earth years in Venus orbit. AKATSUKI was successfully launched at 06:58:22JST on May 21, 2010, by H-IIA F17. After the separation from H-IIA, the telemetry from AKATSUKI was normally detected by DSN Goldstone station (10:00JST) and the solar cell paddles' deployment was confirmed. After a successful cruise, the malfunction happened on the propulsion system during the Venus orbit insertion (VOI) on Dec. 7, 2010. The engine shut down before the planned reduction in speed to achieve. The spacecraft did not enter the Venus orbit but entered an orbit around the Sun with a period of 203 days. Most of the fuel still had remained, but the orbital maneuvering engine was found to be broken and unusable. However, we have found an alternate way of achieving orbit by using only the reaction control system (RSC). We had adopted the alternate way for orbital maneuver and three minor maneuvers in Nov. 2011 were successfully done so that AKATSUKI would meet Venus in 2015. We are considering several scenarios for VOI using only RCS. © 2013 IAA.

Global lightning and sprite measurements from international space station
Tomoo Ushio, Mitsuteru Sato, Takeshi Morimoto, Makoto Suzuki, Atsushi Yamazaki, Yasuhide Hobara, Masayuki Kikuchi, Umran Inan, Ivan Linscott, Hiroshi Kikuchi, Ryohei Ishida, Yukihiro Takahashi, Toru Adachi, Yuji Sakamoto, Zen Ichiro Kawasaki
International Conference on Atmospheric Electricity, ICAE 2014, 2014, [Peer-reviewed]
International conference proceedings, © International Conference on Atmospheric Electricity, ICAE 2014 The Global Lightning and sprIte MeasurementS (GLIMS) on the International Space Station (ISS) is a mission to detect and locate optical transient luminous events (TLEs) and its associated lightning simultaneously from the non-sun synchronous orbit, and was launched successfully in July, 2012 as part of the multi-mission consolidated equipment on Japanese Exposure Module (JEM). Our mission goals are to identify temporal and spatial evolutions of lightning and TLEs and to clarify the occurrence conditions of TLEs and global occurrence locations and rates of TLEs from the nadir observation. To achieve these goals, two CMOS cameras, six Photometers, VLF receiver, and VHF interferometer with two antennas, are installed at the bottom of the module to observe the TLEs as well as causative lighting discharges at nadir direction during day and night time. Though the luminous events so-called sprite, elves and jets have been investigated by numerous researchers all over the world based mainly on the ground observations, some important problems have not been fully understood yet such as generation mechanisms of columniform fine structure and horizontal offset of some sprites from the parent lightning discharges. In the JEM-GLIMS mission, observations from our synchronized sensors are going to shed light on above-mentioned unsolved problems regarding TLEs as well as causative lighting discharges. JEM-GIMS was successfully launched and transported to the ISS by the H-II Transfer Vehicle (HTV) No.3 cargo transporter at the end of July 2012, and started its operation from December 2012. So far, more than one thousand events were recorded. In this paper, we present on the mission overview, examples of the observation results, and several initial analysis for the observed events such as on the identification of the intra-cloud and ground flashes from optical measurements and lightning location from the broad band interferometry at VHF band.

One-month periodicity in lightning activity and tropical cloud variations
Yukihiro Takahashi, Mitsuteru Sato, Kozo Yamashita
2014 XXXITH URSI GENERAL ASSEMBLY AND SCIENTIFIC SYMPOSIUM (URSI GASS), IEEE, 2014, [Peer-reviewed]
English, International conference proceedings

An ELF Signal Associated with a Positive GC Lightning Event in Winter　　　　　　　　　　　　　　　
Honma. N, Y. Hongo, D. Tsurushima, F. Tsuchiya, M. Sato, Y. Takahashi
Proc. 23nd International Lightning Detection Conf., 2014
English, Scientific journal

An evaluation of the exposure in nadir observation of the JEM-EUSO mission
J. H. Adams, S. Ahmad, J. -N. Albert, D. Allard, M. Ambrosio, L. Anchordoqui, A. Anzalone, Y. Arai, C. Aramo, K. Asano, M. Ave, P. Barrillon, T. Batsch, J. Bayer, T. Belenguer, R. Bellotti, A. A. Berlind, M. Bertaina, P. L. Biermann, S. Biktemerova, C. Blaksley, J. Biccki, S. Blin-Bondil, J. Bluemer, P. Bobik, M. Bogomilov, M. Bonamente, M. S. Briggs, S. Briz, A. Bruno, F. Cafagna, D. Campana, J. -N. Capdevielle, R. Caruso, M. Casolino, C. Cassardo, G. Castellini, O. Catalano, A. Cellino, M. Chikawa, M. J. Christi, V. Connaughton, J. F. Cortes, H. J. Crawford, R. Cremonini, S. Csorna, J. C. D'Olivo, S. Dagoret-Campagne, A. J. de Castro, C. De Donato, C. de la Taille, L. del Peral, A. Dell'Oro, M. P. De Pascale, M. Di Martino, G. Distratis, M. Dupieux, A. Ebersoldt, T. Ebisuzaki, R. Engel, S. Falk, K. Fang, F. Fenu, I. Fernandez-Gomez, S. Ferrarese, A. Franceschi, J. Fujimoto, P. Galeotti, G. Garipov, J. Geary, U. G. Giaccari, G. Giraudo, M. Gonchar, C. Gonzalez Alvarado, P. Gorodetzky, F. Guarino, A. Guzman, Y. Hachisu, B. Harlov, A. Haungs, J. Hernandez Carretero, K. Higashide, T. Iguchi, H. Ikeda, N. Inoue, S. Inoue, A. Insolia, F. Isgro, Y. Itow, E. Joven, E. G. Judd, A. Jung, F. Kajino, T. Kajino, I. Kaneko, Y. Karadzhov, J. Karczmarczyk, K. Katahira, K. Kawai, Y. Kawasaki, B. Keilhauer, B. A. Khrenov, Jeong-Sook Kim, Soon-Wook Kim, Sug-Whan Kim, M. Kleifges, P. A. Klimov, S. H. Ko, D. Kolev, I. Kreykenbohm, K. Kudela, Y. Kurihara, E. Kuznetsov, G. La Rosa, J. Lee, J. Licandro, H. Lim, F. Lopez, M. C. Maccarone, K. Mannheim, L. Marcelli, A. Marini, G. Martin-Chassard, O. Martinez, G. Masciantonio, K. Mase, R. Matev, A. Maurissen, G. Medina-Tanco, T. Mernik, H. Miyamoto, Y. Miyazaki, Y. Mizumoto, G. Modestino, D. Monnier-Ragaigne, J. A. Morales de los Rios, B. Mot, T. Murakami, M. Nagano, M. Nagata, S. Nagataki, T. Nakamura, J. W. Nam, S. Nam, K. Nam, T. Napolitano, D. Naumov, A. Neronov, K. Nomoto, T. Ogawa, H. Ohmori, A. V. Olinto, P. Orleanski, G. Osteria, N. Pacheco, M. I. Panasyuk, E. Parizot, I. H. Park, B. Pastircak, T. Patzak, T. Paul, C. Pennypacker, T. Peter, P. Picozza, A. Pollini, H. Prieto, P. Reardon, M. Reinabi, M. Reyes, M. Ricci, I. Rodriguez, M. D. Rodriguez Frias, F. Ronga, H. Rothkaehl, G. Roudil, I. Rusinov, M. Rybczynski, M. D. Sabau, G. Saez Cano, A. Saito, N. Sakaki, M. Sakata, H. Salazar, S. Sanchez, A. Santangelo, L. Santiago Cruz, M. Sanz Palomino, O. Saprykin, F. Sarazin, H. Sato, M. Sato, T. Schanz, H. Schieler, V. Scotti, M. Scuderi, A. Segreto, S. Selmane, D. Semikoz, M. Serra, S. Sharakin, T. Shibata, H. M. Shimizu, K. Shinozaki, T. Shirahama, G. Siemieniec-Ozigbio, H. H. Silva Lopez, J. Sledd, K. Slomiriska, A. Sobey, T. Sugiyama, D. Supanitsky, M. Suzuki, B. Szabelska, J. Szabelski, F. Tajima, N. Tajima, T. Tajima, Y. Takahashi, H. Takami, M. Takeda, Y. Takizawa, C. Tenzer, O. Tibolla, L. Tkachev, T. Tomida, N. Tone, F. Trillaud, R. Tsenov, K. Tsuno, T. Tymieniecka, Y. Uchihori, O. Vaduvescu, J. F. Valdes-Galicia, P. Vallania, L. Valore, G. Vankova, C. Vigorito, L. Villasenor, P. von Ballmoos, S. Wada, J. Watanabe, S. Watanabe, J. Watts, M. Weber, T. J. Weiler, T. Wibig, L. Wiencke, M. Wille, J. Wilms, Z. Wlodarczyk, T. Yamamoto, Y. Yamamoto, J. Yang, H. Yano, I. V. Yashin, D. Yonetoku, K. Yoshida, S. Yoshida, R. Young, A. Zamora, A. Zuccaro Marchi
ASTROPARTICLE PHYSICS, 44, 76, 90, ELSEVIER SCIENCE BV, Apr. 2013, [Peer-reviewed]
English, Scientific journal, We evaluate the exposure during nadir observations with JEM-EUSO, the Extreme Universe Space Observatory, on-board the Japanese Experiment Module of the International Space Station. Designed as a mission to explore the extreme energy Universe from space, JEM-EUSO will monitor the Earth's nighttime atmosphere to record the ultraviolet light from tracks generated by extensive air showers initiated by ultra-high energy cosmic rays. In the present work, we discuss the particularities of space-based observation and we compute the annual exposure in nadir observation. The results are based on studies of the expected trigger aperture and observational duty cycle, as well as, on the investigations of the effects of clouds and different types of background light. We show that the annual exposure is about one order of magnitude higher than those of the presently operating ground-based observatories. (C) 2013 Elsevier B.V. All rights reserved.

Nadir Observations of Lightning and TLEs by JEM-GLIMS　　　　　　　　　　　　　　　
M. Sato, T. Ushio, T. Morimoto, M. Suzuki, A. Yamazaki, M. Kikuchi, Y. Takahashi, I. Umran, L. Ivan, Y. Hobara
EGU General Assembly 2013, --, Apr. 2013, [Peer-reviewed]
English, International conference proceedings

PERFORMANCE EVALUATION FOR POINTING CONTROL SYSTEM OF THE BALLOON-BORNE TELESCOPE
T. Nakano, R. Fujimura, Y. Sakamoto, K. Yoshida, T. Kuwahara, Y. Shoji, M. Taguchi, M. Yamamoto, Y. Takahashi
SPACE FOR OUR FUTURE, 146, 381, 391, UNIVELT INC, 2013, [Peer-reviewed]
English, International conference proceedings, The balloon-borne telescope is a planetary observation method launching a telescope to the altitude of more than 30 km by a stratospheric balloon. To conduct the long duration observation, the flight gondola has to equip with a pointing control system in order to catch and keep the target star in the field of view of the telescope during the flight. This research aims to develop the high accuracy pointing control system and conduct the technology demonstration flight. The goal of the pointing control is set as 0.1 arcsec. This paper introduces the results of the ground test and simulation study to evaluate the performance of the pointing control system.

Down link optical communication experiment using micro satellite body pointing and collaboration with co-located science instrument
Hiroo Kunimori, Toshihiro Kubooka, Tetsuharu Fuse, Hideki Takenaka, Morio Toyoshima, Toshinori Kuwahara, Kazuya Yoshida, Yoshihiro Tomioka, Kazufumi Fukuda, Junichi Kurihara, Yukihiro Takahashi
Proceedings of the International Astronautical Congress, IAC, 4, 3132, 3136, 2013
International conference proceedings, The laser communication terminal called VSOTA and a 5m GSD multi-spectral high-resolution Cassegrain telescope called HPT will be equipped on a 50kg-class micro satellite RISESAT. VSOTA aims to demonstrate satellite-to-ground laser communication by means of accurate attitude control of the satellite body itself. The HPT is designed to be able to send the coordinate information of the light spot from laser on ground to the attitude control system with a frequency of 10 Hz. RISESAT also carries a single retro-reflector which serves to make sure to keep acquisition and pointing for ground station. Link analysis between HPT and ground station as well as laser ranging laser as a pilot signal in initial acquisition scenario is discussed. ©2013 by the International Astronautical Federation. All rights reserved.

Reflection height of daytime tweek atmospherics during the solar eclipse of 22 July 2009
Hiroyo Ohya, Fuminori Tsuchiya, Hiroyuki Nakata, Kazuo Shiokawa, Yoshizumi Miyoshi, Kozo Yamashita, Yukihiro Takahashi
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 117, AMER GEOPHYSICAL UNION, Nov. 2012, [Peer-reviewed]
English, Scientific journal, We report multipoint observations of daytime tweek atmospherics during the solar eclipse of 22 July 2009. Sixteen and sixty-three tweek atmospherics were observed at Moshiri and Kagoshima, Japan, where the magnitudes of the solar eclipse were 0.458 and 0.966, respectively. This was the first observation of tweek atmospherics during a low-magnitude eclipse (0.458). The average and standard deviation of the reflection height were 94.9 +/- 13.7 km at Moshiri and 87.2 +/- 12.9 km at Kagoshima. The reflection height at Moshiri was almost the same as that for normal nighttime conditions in July (96.7 +/- 12.6 km) in spite of the low magnitude of the eclipse. The reflection height at Kagoshima seems be divided into two parts: propagation across the total solar eclipse path and propagation in the partial solar eclipse path. During the eclipse, we also observed the phase variation in the LF transmitter signals. The average change in the phase delay of the LF signals was 109 degrees for the paths that crossed the eclipse path and 27 degrees for the paths that did not cross the eclipse path. Assuming a normal daytime height for LF waves of 65 km, a ray tracing analysis indicates that the variations in phase correspond to a height increase of 5-6 km for the paths across the eclipse and 1-2 km for partial eclipse paths. The wide range of estimated tweek reflection heights at Kagoshima also suggests a difference in electron density in the lower ionosphere between total and partial solar eclipses.

Ground Test of Attitude Control System for Micro Satellite RISING-2
Nobuo Sugimura, Kazufumi Fukuda, Yoshihiro Tomioka, Masato Fukuyama, Yuji Sakamoto, Toshinori Kuwahara, Tetuya Fukuhara, Kazuya Yoshida, Yukihiro Takahashi
2012 IEEE/SICE INTERNATIONAL SYMPOSIUM ON SYSTEM INTEGRATION (SII), 301, 306, IEEE, 2012, [Peer-reviewed]
English, International conference proceedings, This paper summarizes the attitude control system and evaluation system of the 50kg class micro satellite RISING-2, which has developed by Hokkaido University and Tohoku University from 2010. In 2011, the flight models of each component were completed and now the software of RISING-2 is adjusted in order to put into an orbit in 2013. The missions of RISING-2 are observation of the earth surface, cumulonimbus clouds and planets with a telescope, measurement of the earth surface and ocean temperature distribution using a bolometer array and photography of sprite luminescence phenomenon using thunder observation camera and fish eye camera. To accomplish these scientific missions, the attitude control system needs to satisfy the requirements of observation equipments. This satellite attitude is controlled by the 3-axis reaction wheels in order to point to an arbitrary target direction. Especially, in the case of bolometer array observation, the target direction needs to be changed from deep space direction to the Earth-Center or the earth surface direction. We tried this observation sequence using the static closed loop test system which is constructed by the pre-flight model. Then, the test results illustrate that the attitude control system satisfy the requirements.

The Evaluation Tests of the Attitude Control System of the 50-kg Micro Satellite RISING-2
FUKUDA Kazufumi, SUGIMURA Nobuo, SAKAMOTO Yuji, KUWAHARA Toshinori, YOSHIDA Kazuya, TAKAHASHI Yukihiro
TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, SPACE TECHNOLOGY JAPAN, 10, 28, Td_11, Td_16, THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, 2012
English, The 50-kg class micro satellite RISING-2 is now under development by Tohoku University and Hokkaido University. The development is at Flight Model phase and some components are tested to evaluate its specifications. In this paper, the endurance tests using vacuum chamber and thermal test chamber in Tohoku University are described. There was no problem in those tests. In addition, the attitude control accuracy of the RISING-2 was analyzed in the simulation. This simulation based on component specifications and also included noise data. The results show the pointing error angle was less than required error angle.

Return to venus of the Japanese venus climate orbiter akatsuki
Masato Nakamura, Yasuhiro Kawakatsu, Chikako Hirose, Takeshi Imamura, Nobuaki Ishii, Takumi Abe, Atsushi Yamazaki, Manabu Yamada, Kazunori Ogohara, Kazunori Uemizu, Tetsuya Fukuhara, Shoko Ohtsuki, Takehiko Satoh, Makoto Suzuki, Munetaka Ueno, Naomoto Iwagami, Makoto Taguchi, Shigeto Watanabe, Yukihiro Takahashi, George L. Hashimoto, Hiroki Yamamoto
Proceedings of the International Astronautical Congress, IAC, 3, 1727, 1732, 2012
International conference proceedings, Japanese Venus Climate Orbiter/AKATSUKI was proposed in 2001 with strong support by international Venus science community and approved as an ISAS (Institute of Space and Astronautical Science) mission soon after the proposal. The mission life we expected was more than two Earth years in Venus orbit. AKATSUKI was successfully launched at 06:58:22JST on May 21, 2010, by H-IIA F17. After the separation from H-IIA, the telemetry from AKATSUKI was normally detected by DSN Goldstone station (10:00JST) and the solar cell paddles' expansion was confirmed. The malfunction happened on the propulsion system during the Venus orbit insertion (VOI) on Dec 7, 2010. We failed to make the spacecraft become a Venus orbiter, and the spacecraft entered an orbit around the Sun with a period of 203 days. Most of the fuel still had remained, but the orbital maneuvering engine was found to be broken. We decided to use only the reaction control system (RCS) for orbital maneuver and three minor maneuvers in Nov 2011 were successfully done so that AKATSUKI will meet Venus in 2015. We are considering several scenarios for VOI using only RCS. Copyright © (2012) by the International Astronautical Federation.

MSI: a visible multi-spectral imager for 1.6-m telescope of Hokkaido University
Makoto Watanabe, Yukihiro Takahashi, Mitsuteru Sato, Shigeto Watanabe, Tetsuya Fukuhara, Ko Hamamoto, Akihito Ozaki
GROUND-BASED AND AIRBORNE INSTRUMENTATION FOR ASTRONOMY IV, 8446, 84462O, SPIE-INT SOC OPTICAL ENGINEERING, 2012
English, International conference proceedings, We have built a visible multi-spectral imager (MSI) for the 1.6-m Pirka telescope of the Hokkaido University in Hokkaido, Japan. The instrument is equipped with two liquid crystal tunable filters and a 512 x 512 pixel EMCCD camera. One of the major purposes of this instrument is to obtain multi-spectral images (series of narrow-band images at many different wavelengths) of the solar planets rapidly. These tunable filters are a Lyot filter with liquid crystal variable retarders and thus can tune the transmitting wavelength rapidly without moving parts. Their spectral ranges are 400-720 nm and 650-1100 nm and the bandwidth is typically 10 nm on both filters. The EMCCD camera can obtain images at a frame rate of about 32 Hz, which also enables us to improve the spatial resolution with the shift-and-add or the Lucky imaging techniques. The field of view is 3.3 x 3.3 arcmin with a pixel scale of 0.39 arcsec pixel(-1). The instrument also has UBV RI-band broad-band filters and several narrow-band filters. MSI is mounted at the f/12 Cassegrain focus of the telescope. It had the first light on February 2011, and then have been used for several astronomical and planetary science programs as a major facility instrument at this telescope. We describe the design, construction, integration, and performance of this multi-spectral imager.

The Pointing Control Method of Balloon-Borne Telescope Compensating the Motion of Flexible Base
Nakano Toshihiko, Shoji Yasuhiro, Yamamoto Mutsumi, Hamamoto Ko, Nakamoto Jumpei, Imai Masataka, Sakamoto Yuji, Kuwahara Toshinori, Watanabe Makoto, Takahashi Yukihiro, Yoshida Kazuya, Taguchi Makoto, IEEE
2012 Ieee/sice International Symposium on System Integration (Sii), 313, 318, IEEE, 2012, [Peer-reviewed]
International conference proceedings

The Global Lightning and Sprite Measurement (GLIMS) Mission of the International Space Station - Concept and Overview -
Ushio, T, M. Sato, T. Morimoto, M. Suzuki, H. Kikuchi, A. Yamazaki, Y. Takahashi, Y. Hobara, U. Inan, I. Linscott, Y. Sakamoto, R. Ishida, M. Kikuchi, K. Yoshida, Z. Kawasaki
IEEJ Transactions on Fundamentals and Materials, 131, 12, 971, 976, The Institute of Electrical Engineers of Japan, Dec. 2011, [Peer-reviewed]
English, Scientific journal, Global Lightning and sprIte MeasurementS (GLIMS) is a mission on the International Space Station (ISS) to detect and locate optical transient luminous events (TLEs) and associated lightning simultaneously from the non-sun-synchronous orbit. It is scheduled to be launched from Japan in January, 2012 as part of the multi-mission consolidated equipment on the Japanese Exposure Module (JEM). Our mission's goals are (1) to detect and locate lightning and sprites within storm scale resolution over a large region of the Earth's surface along the orbital track of the ISS without any bias, (2) to clarify the mechanism by which sprites are generated, and (3) to identify the conditions under which TLEs occur. To achieve these goals, two CMOS cameras, six Photometers, a VLF receiver and VHF interferometer with two antennas are installed at the bottom of the module to observe the TLEs, as well as causative lightning discharges at nadir direction during day and night time. Though the luminous events' so-called sprites, elves and jets have been investigated by numerous researchers all over the world based mainly on ground observations, some important problems have not been fully understood yet. These include the generation mechanisms of columniform fine structures and horizontal offset of some sprites from the parent lightning discharges. In the JEM-GLIMS mission, observations from our synchronized sensors will shed light on the unsolved problems mentioned above regarding TLEs and causative lightning discharges. In this presentation scientific background, instrumentation, and project summaries are given.

Development Status and Operation Plan of 50-kg Microsatellite RISING-2 for Earth Observations by Multi-Spectrum Instruments　　　　　　　　　　　　　　　
Yuji Sakamoto, Toshinori Kuwahara, Yoshihiro Tomioka, Kazufumi Fukuda, Steve Battazzo, Kazuya Yoshida, Tetsuya Fukuhara, Junichi Kurihara, Yukihiro Takahashi
The 28th International Symposium on Space Technology and Science (ISTS), Naha, Japan, June 2011, No.2011-f-25., Jun. 2011
English, International conference proceedings

Detection of transient ELF emission caused by the extremely intense cosmic gamma-ray flare of 27 December 2004
Y. T. Tanaka, M. Hayakawa, Y. Hobara, A. P. Nickolaenko, K. Yamashita, M. Sato, Y. Takahashi, T. Terasawa, T. Takahashi
GEOPHYSICAL RESEARCH LETTERS, 38, L08805, AMER GEOPHYSICAL UNION, Apr. 2011, [Peer-reviewed]
English, Scientific journal, We report on the first clear detection of transient Extremely-Low-Frequency (ELF) signal caused by an extremely intense cosmic gamma-ray flare. On 2004 December 27, the brightest gamma-ray flare ever recorded was observed by numerous satellites. A transient ELF emission observed at Moshiri and Onagawa in Japan exactly coincided with the peak time of the flare, and its wide pulse width of similar to 40 ms disfavors the possibility of lightning origin. Furthermore, the two horizontal components of ELF magnetic field data recorded at Esrange in Sweden showed clear transient Schumann resonance waveforms. The source direction determined by the Lissajous method roughly corresponds to the subflare point. The chance probability that a sprite occurs within 30 ms of the peak flare time is similar to 0.025%, which again clearly excludes the sprite origin. Thus, a bright cosmic gamma-ray flare is a new source of transient ELF radio signals observed on the Earth, although the emission mechanism needs to be clarified in future. Citation: Tanaka, Y. T., M. Hayakawa, Y. Hobara, A. P. Nickolaenko, K. Yamashita, M. Sato, Y. Takahashi, T. Terasawa, and T. Takahashi (2011), Detection of transient ELF emission caused by the extremely intense cosmic gamma-ray flare of 27 December 2004, Geophys. Res. Lett., 38, L08805, doi: 10.1029/2011GL047008.

Implications for the low latitude cloud formations from solar activity and the quasi-biennial oscillation
Hong Peng K, Miyahara Hiroko, Yokoyama Yusuke, Takahashi Yukihiro, Sato Mitsuteru
JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS, 73, 5月6日, 587, 591, Apr. 2011, [Peer-reviewed]

Improvement in lightning geolocation by time-of-arrival method using global ELF network data
Kozo Yamashita, Yukihiro Takahashi, Mitsuteru Sato, Hiromi Kase
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 116, AMER GEOPHYSICAL UNION, Feb. 2011, [Peer-reviewed]
English, Scientific journal, The global observation of cloud-to-ground (CG) discharges based on ELF measurements provides essential information, including vertical charge moment (Qdl) for investigations of global-scale thunderstorm activity. However, the geolocating method by direction finding of sferics in the frequency range of 1-100 Hz has a rather large error, on the order of 1000 km, even for the CGs with relatively large Qdl (>1000 C-km). Here we improve the methods for geolocation and estimation of Qdl, which are applicable to smaller CGs with Qdl down to 470 C-km, making use of the time-of-arrival method and the high correlation between Qdl and the peak amplitude of ELF sferics. The evaluated average error in geolocation, comparing with World Wide Lightning Location Network data, is 680 km. By this improved method, CGs with Qdl of <470 C-km can be detected at any location in the world. In the preliminary analysis for the year of 2004, the number of CGs whose location and Qdl are determined is about a million events per month, roughly 10-30 times compared to previous studies by ELF measurement, enabling an investigation of the day-to-day variations of the global CG distribution with transferred charge amount. The combination of accurate geolocation and the uniformity of detection show active regions in the three main areas: Africa, South America, and the Maritime Continent. In addition, minor thunderstorm areas in Japan, the Mediterranean Sea, and the Pacific Ocean can be monitored.

Static closed loop test system for attitude control system of micro satellite RISING-2
Kazufumi Fukuda, Yuji Sakamoto, Toshinori Kuwahara, Kazuya Yoshida, Yukihiro Takahashi
2011 IEEE/SICE International Symposium on System Integration, SII 2011, 890, 895, 2011, [Peer-reviewed]
English, International conference proceedings, 50-kg class micro satellite RISING-2 is now under development by Tohoku University and Hokkaido University. The development is at Flight Model phase. The main mission of the RISING-2 is Earth surface observations with 5-m resolution using a Cassegrain telescope with 10-cm diameter and 1-m focal length. Accurate attitude control capability with less than 0.1 deg direction errors and less than 0.02 deg/s angular velocity errors is required to realize this observation. The attitude control system realizes 3-axis stabilization for the observation by means of star sensors, gyro sensors, sun attitude sensors and reaction wheels. In this paper the static closed loop test system for the attitude control system of the RISING-2 is described. This test system is the simulation including the hardware of the attitude control system of the RISING-2. The results of the tests show that the pointing error is very larger than the results of software simulation. © 2011 IEEE.

A Japanese microsatellite bus system for international scientific missions
Toshinori Kuwahara, Kazuya Yoshida, Yuji Sakamoto, Yukihiro Takahashi, Junichi Kurihara, Hiroshi Yamakawa, Atsushi Takada
62nd International Astronautical Congress 2011, IAC 2011, 5, 3699, 3706, 2011
International conference proceedings, Professor Shinichi Nakasuka of University of Tokyo is now leading a small satellite development activity within the scope of a Japanese FIRST (Funding Program for World-Leading Innovative R&D on Science and Technology) program. In this program several 50-kg class micro-satellites are going to be developed and launched by the end of Japanese fiscal year of 2013, including one scientific micro-satellite under international cooperation. This program as whole shall contribute to enhance the activities of world's small satellite research societies and industries, and to build the basis of new paradigm for the future, where cost-effective and reliable small satellites are widely utilized for both research and business purposes. Tohoku University has been assigned as the project leader of the above mentioned international scientific micro-satellite, named as RISESAT (Rapid International Scientific Experiment Satellite), and is developing the bus system as well as organizing scientific payload instruments from all over the world together with Hokkaido University and Kyoto University. This satellite shall demonstrate the performance of its bus system which is supposed to be offered as a common bus system for international scientific missions in the future. The selection of scientific instruments is almost finished. The orbit of me RISESAT is planned to be a sun-synchronous orbit with an altitude of between 500km and 800km. In order to accommodate as many payload instruments as possible, the satellite is equipped with two deployable side solar panels enabling a maximum power consumption of up to about 100 W. Many of the attitude determination and control components are going to be developed by the Space Robotics Laboratory of the Tohoku University achieving an attitude control accuracy of better than 0.1 deg. It is also equipped with an X-band transmitter for mission data downlink. The electrical interface between the payload instruments and the bus system is based on a space plug and play avionics standard. The development of engineering model of the RISESAT will be completed by March 2012. This paper summarizes the system design of the satellite and progress report of the development activities, as well as the brief description of selected scientific instruments. Copyright ©2011 by the International Astronautical Federation. All rights reserved.

Improvement in lightning geolocation by time-of-arrival method using global ELF network data
Kozo Yamashita, Yukihiro Takahashi, Mitsuteru Sato, Hiromi Kase
Journal of Geophysical Research: Space Physics, 116, 2, Blackwell Publishing Ltd, 2011, [Peer-reviewed]
English, Scientific journal, The global observation of cloud-to-ground (CG) discharges based on ELF measurements provides essential information, including vertical charge moment (Qdl) for investigations of global-scale thunderstorm activity. However, the geolocating method by direction finding of sferics in the frequency range of 1-100 Hz has a rather large error, on the order of 1000 km, even for the CGs with relatively large Qdl (>
1000 C-km). Here we improve the methods for geolocation and estimation of Qdl, which are applicable to smaller CGs with Qdl down to 470 C-km, making use of the time-of-arrival method and the high correlation between Qdl and the peak amplitude of ELF sferics. The evaluated average error in geolocation, comparing with World Wide Lightning Location Network data, is 680 km. By this improved method, CGs with Qdl of <
470 C-km can be detected at any location in the world. In the preliminary analysis for the year of 2004, the number of CGs whose location and Qdl are determined is about a million events per month, roughly 10-30 times compared to previous studies by ELF measurement, enabling an investigation of the day-to-day variations of the global CG distribution with transferred charge amount. The combination of accurate geolocation and the uniformity of detection show active regions in the three main areas: Africa, South America, and the Maritime Continent. In addition, minor thunderstorm areas in Japan, the Mediterranean Sea, and the Pacific Ocean can be monitored. Copyright 2011 by the American Geophysical Union.

「月惑星探査の来たる10年」検討・第一段階報告　　　　　　　　　　　　　　　
大谷栄治, 倉本圭, 今村剛, 寺田直樹, 渡部重十, 荒川政彦, 伊藤孝士, 圦本尚義, 渡部潤一, 木村淳, 高橋幸弘, 中島健介, 中本泰史, 三好由純, 小林憲正, 山岸明彦, 並木則行, 小林直樹, 出村裕英, 大槻圭史
日本惑星科学会誌, 20, 350, 366, 2011, [Peer-reviewed]
Japanese, Scientific journal

Absolute optical energy of sprites and its relationship to charge moment of parent lightning discharge based on measurement by ISUAL/AP
Y. Takahashi, A. Yoshida, M. Sato, T. Adachi, S. Kondo, R. -R. Hsu, H. -T. Su, A. B. Chen, S. B. Mende, H. U. Frey, L. -C. Lee
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 115, AMER GEOPHYSICAL UNION, Sep. 2010, [Peer-reviewed]
English, Scientific journal, Although the Quasi-electrostatic (QE) model has been considered a basic mechanism for describing sprite generation, the relationship between sprite luminosity and the charge moment change (CMC) value, caused by the sprites' parent lightning has not been examined quantitatively. CMC value represents the energy of cloud-to-ground discharge (CG) and the electric field intensity above the thunderstorm. We focused on the data obtained in 2004, in which both ISUAL on board the FORMOSAT-2 satellite and the Tohoku ELF network were operated throughout one year. We could estimate the absolute luminous intensity of sprites free from atmospheric influence with the ISUAL/Array Photometer (AP) and investigated its relationship to the charge moment of parent lightning. Absolute optical energies emitted from sprites were estimated for 14 streamer-type sprites for the first time. The averages of the time-integrated optical energies are 176 kJ and 119 kJ for the N2 1PG and N2 2PG bands, respectively. Furthermore, the optical energies and the charge moments of their parent lightning estimated with ELF data show a high correlation (correlation coefficient = 0.93), that is consistent, qualitatively, with the QE model. This relationship predicts that the 50% occurrence probability is located at similar to 600 C km, which coincides with previous statistical studies.

ISUAL far-ultraviolet events, elves, and lightning current
S. C. Chang, C. L. Kuo, L. J. Lee, A. B. Chen, H. T. Su, R. R. Hsu, H. U. Frey, S. B. Mende, Y. Takahashi, L. C. Lee
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 115, AMER GEOPHYSICAL UNION, Jul. 2010, [Peer-reviewed]
English, Scientific journal, The Imager of Sprites and Upper Atmospheric Lightnings (ISUAL) often recorded events that have significant far-ultraviolet (FUV) emissions in the spectrophotometer but have no discernible transient luminous events (TLEs) in the imager. These FUV events likely are dim TLEs. To confirm the conjecture, lightning emissions were simulated and proved to be completely absorbed by the atmosphere. The FUV emission of the FUV events follows the lightning OI emission within 1 ms, similar to the characteristics of elves. After analyzing the imager-N(2)1P brightness of the elves and their FUV intensity, a linear correlation was found, which is consistent with the work of Kuo et al. (2007). The intensity of the FUV events ranks among the dimmest elves and is less than 1 x 10(4) photons/cm(2). Combining all the information, the FUV events are identified as dim elves that eluded the detection of the ISUAL imager. Also from the detection limits of the ISUAL spectrophotometer (SP) and the imager, for the before-the-limb elves the detection number of SP is found to be nearly 16 times higher than that of the imager. This result is consistent with a related factor of similar to 13 that was inferred from the U. S. National Lightning Detection Network (NLDN) peak current distribution for the negative cloud-to-ground lightning. Hence the ISUAL spectrophotometer can be used to perform elve survey, to infer the peak current of the elve-producing lightning, and possibly to be used to deduce other lightning parameters. Evidence is also found for the existence of multielves, which are FUV events from the M-components or the multiple strokes in lightning flashes.

Attitude control system of micro satellite RISING-2
Kazufumi Fukuda, Toshihiko Nakano, Yuji Sakamoto, Toshinori Kuwahara, Kazuya Yoshida, Yukihiro Takahashi
2010 IEEE/SICE International Symposium on System Integration: SI International 2010 - The 3rd Symposium on System Integration, SII 2010, Proceedings, 373, 378, 2010, [Peer-reviewed]
English, International conference proceedings, This paper summarizes the attitude control system of the 50-kg micro satellite RISING-2, which is now under development by the Tohoku University and Hokkaido University. The main mission of the RISING-2 is Earth surface observations with 5-m resolution using a Cassegrain telescope with 10-cm diameter and 1-m focal length. Accurate attitude control capability with less than 0.1 deg direction errors and less than 0.02 deg/s angular velocity errors is required to realize this observation. In addition, because of the larger power consumption of the science units than expected, actuators must be operated with sufficiently low power. The attitude control system realizes 3-axis stabilization for the observation by means of star sensors, gyro sensors, sun attitude sensors and reaction wheels. In this paper the attitude control law of the RISING-2 is analyzed to keep the power of reaction wheels under the limit. This simulation is based on component specifications and also includes noise data of the components which are under development. The simulation results show that the pointing error is less than 0.1 deg in most time with the RISING-2 attitude control system. ©2010 IEEE.

The balloon-borne telescope system for optical observation of planets
Toshihiko Nakano, Yuji Sakamoto, Kazuya Yoshida, Toshinori Kuwahara, Yasuhiro Shoji, Makoto Taguchi, Mutumi Yamamoto, Yukihiro Takahashi
2010 IEEE/SICE International Symposium on System Integration: SI International 2010 - The 3rd Symposium on System Integration, SII 2010, Proceedings, 236, 241, 2010, [Peer-reviewed]
English, International conference proceedings, Our team is carrying out the project of Planet observation with high precision using balloon-borne telescope. The first model, BBT-1 was equipped with a three stage pointing system and an optical system to observe the detailed structure of the atmospheric motion of Venus. The first flight test was conducted in 2009, and the performance of the system was verified. However, because of a trouble of onboard computer, the flight operation could not been finished as planned. The second model "BBT-2" is now being developed and the next flight test is planned in 2011.The BBT-2 has a bus system including FPGAs and CPU,and it is expected to be more stable than the BBT-1. ©2010 IEEE.

SPRITE-SAT: A University Small Satellite for Observation of High-Altitude Luminous Events
Yukihiro Takahashi, Kazuya Yoshida, Yuji Sakamoto, Takeshi Sakamoi
SMALL SATELLITE MISSIONS FOR EARTH OBSERVATION, 197, +, SPRINGER-VERLAG BERLIN, 2010, [Peer-reviewed]
English, International conference proceedings, SPRITE-SAT is a micro satellite in the size of 50 cm cube and weighing 45-kg, designed and developed by Tohoku University. Its mission objective is to conduct scientific observation of atmospheric luminous emissions called "sprites" and terrestrial Gamma-ray flushes. Both are recently discovered phenomena and their mechanisms are still under the veil. SPRITE-SAT was developed to achieve significant observations to determine clear models of these mysterious phenomena. On January 23rd, 2009, SPRITE-SAT was successfully launched by JAXA's H-IIA rocket as a piggyback payload of Greenhouse Gas Observation Satellite (GOSAT). The spacecraft is now in a sun-synchronous polar orbit with 670 km altitude form the Earth's surface.

Development of the microsatellite rising-2 by Tohoku University and Hokkaido University
Yuji Sakamoto, Yukihiro Takahashi, Kazuya Yoshida, Kazufumi Fukuda, Toshihiko Nakano, Steve Battazzo, Tetsuya Fukuhara, Junichi Kurihara
61st International Astronautical Congress 2010, IAC 2010, 1, 469, 473, 2010
International conference proceedings, Tohoku University and Hokkaido University started the development of a new 41-kg microsatellite RISING-2 at July 2009. This satellite inherits the development technique of RISING (SPRITE-SAT) launched on January 2009. The progress of RISING-2 project is shown in this paper. Using a Cassegrain telescope with 10-cm diameter and 1-m focal length, earth surface is observed with 5-m resolution from 700-km-alt sun synchronous orbit. By 3-axis attitude stabilization using reaction wheels and star sensors, the designated area on earth surface can be observed. In addition to color images, multi-spectrum images of cumulonimbus are observed by using a liquid crystal tunable filter. As a secondary mission, transient luminous events such as sprite are observed, which is same mission as SPRITE-SAT. Copyright ©2010 by the International Astronautical Federation. All rights reserved.

S1901-2-1 Development of the microsatellite RISING-2 by Tohoku University and Hokkaido University
SAKAMOTO Yuji, YOSHIDA Kazuya, TAKAHASHI Yukihiro
The proceedings of the JSME annual meeting, 2010, 371, 372, The Japan Society of Mechanical Engineers, 2010
Japanese, Tohoku University and Hokkaido University started the development of a new 50-kg microsatellite RISING-2 at July 2009. This satellite inherits the development technique of RISING (SPRITE-SAT) launched on January 2009. The progress is shown in this paper. Using a Cassegrain telescope with 10-cm diameter and 1-m focal length, earth surface is observed with 5-m resolution from 700-km-alt sun synchronous orbit. By 3-axis attitude stabilization using reaction wheels and star sensors, the designated area on earth surface can be observed. In addition to color images, multi-spectrum images of cumulonimbus are observed by using a liquid crystal tunable filter. As a secondary mission, transient luminous events such as sprite are observed, which is same mission as SPRITE-SAT.

Highly Precise Pointing Control System on a Balloon-Borne Telescope for Optical Observations of Planets
SHOJI Yasuhiro, ONISHI Tomoya, BATTAZZO Steve, TERAGUCHI Tomoko, YOSHIMURA Atsushi, SAKAMOTO Yuji, TAKAHASHI Yukihiro, YOSHIDA Kazuya, TAGUCHI Makoto
TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, SPACE TECHNOLOGY JAPAN, 8, 27, Pm_15, Pm_20, THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, 2010
English, A balloon borne telescope is one of the space observation methods by carrying a telescope to the stratosphere with a huge balloon in order to be free from the atmospheric influences on observations. The authors have been developing a balloon borne telescope system for optical observations of other planets in the solar system. The observation aimed to achieve finer images of the planets than those taken by ground telescopes, which required the balloon borne telescope to hold the target star with subarcsec precision during the exposure of the camera. To meet the requirement, the system is equipped three stage pointing system. This article introduces the overview of the flight campaign and the flight system, and reports the pointing performance verified in ground experiments.

Pre-Flight Analysis, Test Evaluation and Flight Verification of the Thermal System of Tohoku University SPRITE-SAT
SAKAMOTO Yuji, NAKAZATO Yasuhiro, SAWAKAMI Tomoki, YOSHIDA Kazuya, TAKAHASHI Yukihiro
TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, SPACE TECHNOLOGY JAPAN, 8, 27, Tf_1, Tf_6, THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, 2010
English, The microsatellite SPRITE-SAT developed by Tohoku University was launched in January 2009. Regarding the thermal system of SPRITE-SAT, the mathematical model, the parameter determination for the heat transfer coefficients, and the comparison between the estimate and real temperature in flight mode are shown in this paper. The precision of thermal analysis using the simple 7-node model was solved. The estimate error of temperature in orbit is less than 5 degrees Celsius in panels with most of instruments.

27-day variation in cloud amount in the Western Pacific warm pool region and relationship to the solar cycle
Y. Takahashi, Y. Okazaki, M. Sato, H. Miyahara, K. Sakanoi, P. K. Hong, N. Hoshino
ATMOSPHERIC CHEMISTRY AND PHYSICS, 10, 4, 1577, 1584, COPERNICUS GESELLSCHAFT MBH, 2010, [Peer-reviewed]
English, Scientific journal, Although linkages between solar activity and the earth's climate have been suggested and the 11-year cycle in solar activity evident in sunspot numbers is the most examined example of periodicity in previous studies, no quantitative evidence indicating a relationship for tropospheric phenomena has been found for a short period. Based on FFT analysis for OLR (Outgoing Longwave Radiation) compared with the F10.7 index, we clearly demonstrate a 27-day variation in the cloud amount in the region of the Western Pacific warm pool, which is only seen in the maximum years of 11-year solar activity. The average spectrum in such years also shows an enhancement in the range of the MJO (Madden-Julian Oscillation) period. Although there exist some explanations for possible mechanisms, the exact cause is unknown. Therefore, the proposed connection between 27-day cloud variation and solar cycle in the WPWP region is still a hypothesis and various kinds of varification based on other meteorological and solar parameters are strongly required.

Ground-based detection of sprites and their parent lightning flashes over Africa during the 2006 AMMA campaign
Williams, E, W.A. Lyons, Y. Hobara, V. Mushtak, N. Asencio, R. Boldi, J. Bo r, S. Cummer, E. Greenberg, M. Hayakawa, R. Holzworth, V. Kotroni, J. Li, C. Morales, T. Nelson, C. Price, B. Russell, M. Sato, G. Satori, K. Shirahata, Y. Takahashi, K. Yamashita
Q. J. R. Meteorol. Soc., 136, 257, 271, Dec. 2009, [Peer-reviewed]
English, Scientific journal

Present Status and Scope of TLE and TGF Studies
TAKAHASHI Yukihiro
IEEJ Transactions on Fundamentals and Materials, 129, 4, 163, 167, The Institute of Electrical Engineers of Japan, 01 Apr. 2009
Japanese, Lightning is discharge phenomenon between thunderclouds and the ground, or inside/between thunderclouds. However, a new type of atmospheric discharge was found in 1989 by chance: a discharge between thundercloud and ionosphere, named "sprites". After this discovery, similar types of transient luminous events in the middle and upper atmosphere, called TLEs, have been reported. On the other hand, gamma-ray flash radiated from the thundercloud, called TGF, was found in 1994 by satellite observation. Detail characteristics, mechanisms and effects on the atmosphere are not well understood both for TLE and TGF, although the extensive investigations have been carried out experimentally and theoretically for more than a decade. Here we review these phenomena and introduce the latest projects to solve the fundamental scientific problems.

Development of a Multi-Spectrum Imager for the S-520 Sounding Rocket
SHOJI Yasuhiro, YOSHIKAWA Takashi, SAKAMOTO Yuji, TAKAHASHI Yukihiro, YOSHIDA Kazuya
TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN, 7, 26, Tn_7, Tn_12, THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, 2009
English, An S-520 sounding rocket was launched in the summer of 2007 in order to observe magneto electric phenomena in high sky and to verify a new spectroscopic observation method. A Multi-Spectrum Imager (MSI) was developed for the latter aim. The observation device is equipped a spectroscopic camera with a liquid crystal tunable filter and a pointing system to control the pointing direction to take spectroscopic images of a target against the spin of the rocket body. With the successful flight of the sounding rocket, the MSI succeeded in taking and sending approximately 30 pictures and the house keeping data.

Dynamic Modeling and Experimental Verification of the Pointing Technology in Balloon-Borne Telescope System for Optical Remote Sensing of Planets
SAKAMOTO Yuji, KANAZAWA Tomoaki, SHOUJI Yasuhiro, TAKAHASHI Yukihiro, YOSHIDA Kazuya, TAGUCHI Makoto
TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN, 7, 26, Pd_23, Pd_28, THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, 2009
English, Tohoku University and Rikkyo University are carrying out the project of Venus observation with high precision using a balloon-borne telescope. In this paper, the outline of Balloon-Borne Telescope for the optical remote sensing of Venus is introduced, and the simulation model of three-stage control method is constructed. For this observation, the pointing technology with high precision to restrain the slight moving of image is necessary. The target precision is only 0.1 arc seconds. The dynamics and control model is defined firstly, and the model parameters are determined by the experimental verification. By developing the numerical simulation tool, the motion can be estimated in the simulator, and the control strategy can be more easily optimized compared to the gain adjustment only based on experiments.

S1901-1-2 Development and Flight Operation of Tohoku University SPRITE-SAT
SAKAMOTO Yuji, YOSHIDA Kazuya, SAWAKAMI Tomoki, SAKANOI Takeshi, TAKAHASHI Yukihiro
The proceedings of the JSME annual meeting, 2009, 245, 246, The Japan Society of Mechanical Engineers, 2009
Japanese, The microsatellite SPRITE-SAT developed by Tohoku University was launched in January 2009. The mission is the observation of Sprite phenomena and Terrestrial Gamma-ray Flashes incidental on lightning discharges. In the 12 days after launch, the satellite is normally operated. But because it is damaged by a serious trouble at February 4, 2009, the data communication including uplink and downlink is not successful now. This paper shows the outlines of satellite system, flight operation results, and the reason of trouble.

Electric fields and electron energies in sprites and temporal evolutions of lightning charge moment
T. Adachi, Y. Hiraki, K. Yamamoto, Y. Takahashi, H. Fukunishi, R-R Hsu, H-T Su, A. B. Chen, S. B. Mende, H. U. Frey, L. C. Lee
JOURNAL OF PHYSICS D-APPLIED PHYSICS, 41, 23, IOP PUBLISHING LTD, Dec. 2008, [Peer-reviewed]
English, Scientific journal, The fundamental electrodynamical coupling processes between lightning and sprites are investigated. By combining the observed spectral data with the Monte Carlo swarm experiments, reduced electric fields and electron energies in sprite streamers and halos are estimated. The obtained fields inside sprite halos (70-97 Td with an analysis error of +/- 5 Td) are lower than the conventional breakdown field, E-k similar to 128 Td, indicating a significant reduction of electrons associated with halos while those in sprite streamers (98-380 Td with an error of +/- 50 Td) are higher than Ek, suggesting that a significant ionization process drives their formation and development. A combined analysis of photometric and electromagnetic data makes it possible to estimate temporal evolutions of lightning charge moment. It is found that lightning discharges with a short time scale (similar to 1 ms) and a moderate amount of charge moment (similar to 400 C km) produce discernible halos. On the other hand, lightning discharges with a large amount of charge moment (similar to 1300 C km) produce streamers regardless of their time scale. The results obtained are comprehensively interpreted with both the conventional breakdown field necessary for the formation of streamers and the electric field necessary for the production of optical emissions of halo which is sensitive to the time scale of the thundercloud field due to the significant reduction of electrons.

Lightning detection by LAC onboard the Japanese Venus climate orbiter, planet-C
Y. Takahashi, J. Yoshida, Y. Yair, T. Imamura, M. Nakamura
SPACE SCIENCE REVIEWS, 137, 1-4, 317, 334, SPRINGER, Jun. 2008, [Peer-reviewed]
English, Lightning activity in Venus has been a mystery for a long period, although many studies based on observations both by spacecraft and by ground-based telescope have been carried out. This situation may be attributed to the ambiguity of these evidential measurements. In order to conclude this controversial subject, we are developing a new type of lightning detector, LAC (Lightning and Airglow Camera), which will be onboard Planet-C (Venus Climate Orbiter: VCO). Planet-C will be launched in 2010 by JAXA. To distinguish an optical lightning flash from other pulsing noises, high-speed sampling at 50 kHz for each pixel, that enables us to investigate the time variation of each lightning flash phenomenon, is adopted. On the other hand, spatial resolution is not the first priority. For this purpose we developed a new type of APD (avalanche photo diode) array with a format of 8x8. A narrow band interference filter at wavelength of 777.4 nm (OI), which is the expected lightning color based on laboratory discharge experiment, is chosen for lightning measurement. LAC detects lightning flash with an optical intensity of average of Earth's lightning or less at a distance of 3 Rv. In this paper, firstly we describe the background of the Venus lightning study to locate our spacecraft project, and then introduce the mission details.

Development of the attitude control system for Tohoku University SPRITE-SAT using a new-model deployable mast　　　　　　　　　　　　　　　
Yuji Sakamoto, Kazuya Yoshida, Yukihiro Takahashi, Takeshi Sakanoi, Kei Takiuchi, Tomoki Sawakami, Yasuhiro Nakazayo, Satoshi Kondo
International Astronautical Federation - 59th International Astronautical Congress 2008, IAC 2008, 8, 5223, 5230, 2008
English, International conference proceedings, Tohoku University is now developing the 50-kg micro satellite named SPRITE-SAT. The SPRITE-SAT has the deployable mast, which length is 86 cm and the tip-mass weight is 3.68 kg. The deployable mast was newly developed for SPRITE-SAT. In this paper, the hardware mechanism and evaluation method are described. In addition, the control algorithm of magnetic torquers and the numerical simulation in typical control sequence were explained. As results, the validation of hardware and software of attitude control system for SPRITE-SAT was confirmed.

気球搭載望遠鏡による金星観測　　　　　　　　　　　　　　　
田口 真, 吉田 和哉, 坂本 祐二, 荘司 泰弘, 高橋 幸弘, 坂野井 健
平成20年度大気球シンポジウム集録, 2008
Japanese, Research society

Development of the sprite and lightning imaging system onboard the SPRITE-SAT　　　　　　　　　　　　　　　
Sato, M, Y. Takahashi, T. Sakanoi, S. Ueda, S. Kondo, K. Yoshida, Y. Sakamoto, T. Takashima
EOS Trans, AGU, 88, 52, 2008
English, International conference proceedings

Balloon-borne telescope system for optical remote sensing of planetary atmospheres and plasmas
Makoto Taguchi, Kazuya Yoshida, Hiroki Nakanishi, Yasuhiro Shoji, Kohei Kawasaki, Junichi Shimasaki, Yukihiro Takahashi, Jun Yoshida, Daisuke Tamura, Takeshi Sakanoi
Advances in Geosciences: Volume 7: Planetary Science (PS), 169, 179, World Scientific Publishing Co., 01 Jan. 2007, [Peer-reviewed]
English, In book, This paper reports on the ongoing development of a balloon-borne telescope system for remote sensing of planetary atmospheres and plasmas. In this system, a Schmidt-Cassegrain telescope with a 300-mm clear aperture is mounted on a gondola whose attitude is controlled by control moment gyros, an active decoupling motor, and a Sun sensor. The gondola can float in the stratosphere for periods in excess of 1 week. A pointing stability of 10 arcsec/s will be achieved via the cooperative operation of the following three-stage pointing devices: a gondola-attitude control system, two-axis telescope gimbals for coarse guiding, and a tip/tilt mirror mount for guiding error correction. The first target for the system is Venus. Wind vectors in the Venusian upper atmosphere will be derived from the tracking of cloud patterns observed in the ultraviolet and near-infrared regions. An experiment designed to test the system performance is scheduled to take place in Japan during June 2007, and a long-duration flight in the Arctic is scheduled for 2008.

Balloon-borne measurement of UV nightglow and clouds for the JEM-EUSO mission
N. Sakaki, Y. Takizawa, Y. Kawasaki, M. Sato, T. Sawabe, M. Nagano, T. Tsunoda, T. Kamioka, K. Hayasaka, M. Kamimura, A. K. Yoshida, T. Shibata, T. Ebisuzaki, K. Inoue, F. Kajino, Y. Takahashi, Y. Saito, K. Yamada, T. Kawasaki
Proceedings of the 30th International Cosmic Ray Conference, ICRC 2007, 5, HE PART 2, 965, 968, 2007, [Peer-reviewed]
International conference proceedings, Ultra-high energy cosmic rays (UHECRs) above 100 EeV have been observed with several experiments. Their origin and propagation mechanism are still in mystery mainly due to the low statistics. In order to observe UHECRs with sufficient statistics, the JEM-EUSO mission is going on. In the JEMEUSO mission, fluorescence and ̌Cerenkov light from the extensive air showers induced by UHECRs are observed with a telescope attached to the International Space Station. It is important to study the background (BG) intensity in near UV region (300-400nm) seen from the JEM-EUSO telescope. We launched a balloon at Sanriku Balloon Center of JAXA to investigate the nightglow and the clouds on August 29, 2005. The upward and downward nightglow were measured in the eight near UV bands and the cloud images were recorded with an infrared thermography. In this paper, the detail of the experiment and the results will be reported.

Planet-C: Venus Climate Orbiter mission of Japan
Nakamura, M, Imamura, T, Ueno, M, Iwagami, N, Satoh, T, Watanabe, S, Taguchi, M, Takahashi, Y, Suzuki, M, Abe, T, Hashimoto, G. L, Sakanoi, T, Okano, S, Kasaba, Y, Yoshida, J, Yamada, M, Ishii, N, Yamada, T, Uemizu, K, Fukuhara, T, Oyama, K
Planet. Space Sci., 55, 12, 1831, 1842, PERGAMON-ELSEVIER SCIENCE LTD, 01 Jan. 2007, [Peer-reviewed]
English, Scientific journal, The Venus Climate Orbiter mission (PLANET-C), one of the future planetary missions of Japan, aims at understanding the atmospheric circulation of Venus. Meteorological information will be obtained by globally mapping clouds and minor constituents successively with four cameras at ultraviolet and infrared wavelengths, detecting lightning with a high-speed imager, and observing the vertical structure of the atmosphere with radio science technique. The equatorial elongated orbit with westward revolution fits the observation of the movement and temporal variation of the atmosphere which as a whole rotates westward. The systematic, continuous imaging observations will provide us with an unprecedented large data set of the Venusian atmospheric dynamics. Additional targets of the mission are the exploration of the ground surface and the observation of zodiacal light. The mission will complement the ESA's Venus Express, which also explores the Venusian environment with different approaches. (C) 2007 Elsevier Ltd. All rights reserved.

The focal surface of the EUSO telescope
Y Kawasaki, M Bertaina, T Ebisuzaki, F Kajino, Y Miyazaki, M Nagano, N Sakaki, M Sato, HM Shimizu, Y Takizawa, M Ameri, O Catalano, S Cuneo, F Fontanelli, Gracco, V, P Musico, M Pallavicini, A Petrolini, R Pratolongo, M Sannino, N Bleurvacq, F Cadoux, C Chapron, P Gorodetzky, P Nedelec, T Patzak, E Plagnol, Y Takahashi
INTERNATIONAL JOURNAL OF MODERN PHYSICS A, 20, 29, 6890, 6893, WORLD SCIENTIFIC PUBL CO PTE LTD, Nov. 2005, [Peer-reviewed]
English, Scientific journal, The Extreme Universe Space Observatory (EUSO) is a space mission to study extremely high-energy cosmic rays. The EUSO instrument is a wide-angle refractive telescope in near-ultraviolet wavelength region to observe time-resolved atmospheric fluorescence images of the extensive air showers from the International Space Station. The Focal surface is an aspherical curved surface, and its area amounts to about 4.5 m(2). The focal surface detector is designed as a mosaic of multianode photomultipliers (MAPMT) for the single photoelectron counting capability. The strongest requirement for the focal surface detector is the maximization of the photon detection efficiency together with the uniformity over the focal surface. We have developed a new type of MAPMT. It is modified from the ordinary one and has a grid between the photocathode and the first dynode to electrostatically demagnify the photoelectron image on the dynode. We are also developing the HV supply system for a great number of MAPMTs. EUSO experiments the day-time and night-time every 90 minutes. The heat flow must be considered to stabilize the PMT characteristics, in parallel with the heat dissipation of the electronics attached on the focal surface supporting structure.

Electric fields and electron energies inferred from the ISUAL recorded sprites
Cheng-Ling Kuo, R. R. Hsu, A. B. Chen, H. T. Su, L. C. Lee, S. B. Mende, H. U. Frey, H. Fukunishi, Y. Takahashi
Geophysical Research Letters, 32, 19, 1, 4, 16 Oct. 2005, [Peer-reviewed]
English, Scientific journal, Electron energies and the strenght of electric fields in sprites are deduced for five selected events, which were recorded by the space-borne instrument called ISUAL (Imager of Sprites and Upper Atmospheric Lightning
a payload on the FORMOSAT-2 satellite). From the derived peak intensity ratios of spectrophotometer channel 2 (centered at 337 nm) and channel 3 (centered at 391.4 nm) of these sprites, the average and characteristic electron energies were found to be in the range of 6.2-9.2 eV and 4.5-6.5 eV, respectively. The estimated E/N at 40-60 km is 243-443 Td and the strength of the electric field is 2.1 - 3.7 times that of the atmosphere breakdown E-field at these altitudes. The inferred electron energies and the strength of electric fields are about two times higher than those inferred from ground campaigns. However, they are consistent with the prediction of the sprite streamer model. Copyright 2005 by the American Geophysical Union.

Beta-type stepped leader of elve-producing lightning
H. U. Frey, S. B. Mende, S. A. Cummer, A. B. Chen, R. R. Hsu, H. T. Su, Y. S. Chang, T. Adachi, H. Fukunishi, Y. Takahashi
Geophysical Research Letters, 32, 13, 1, 4, 16 Jul. 2005
English, Scientific journal, The Imager for Sprites and Upper Atmospheric Lightning (ISUAL) on the Taiwanese FORMOSAT-2 (formerly ROCSAT-2) spacecraft is the first global observatory of transient luminous events (TLEs). During the first 4 months of operation a large number of elves were observed. Elves are obvious with their far ultraviolet (FUV) signature that is less attenuated by atmospheric O2 at their emission altitude compared to emission from sprites or lightning at lower altitude. About half of all elves were produced by lightning that shows a three-step signature in the photometer signal: (1) An initial brightening in all except the FUV channels, (2) a slow brightness decrease for the next 2-5 milliseconds, and (3) an impulsive increase of signal in all channels. We interpret this specific signature as the initial breakdown with a beta-type stepped leader followed by the bright return stroke of a negative cloud to ground (-CG) lightning. In contrast, sprites follow positive cloud to ground lightning (+CG) without a signature of initial breakdown and stepped leader. Many sprites are associated with the continuing current and can be delayed up to 100 ms after the lightning. Copyright 2005 by the American Geophysical Union.

Lyman alpha imaging of solar activity on the interplanetary hydrogen screen for space weather forecasting
Y Okazaki, H Fukunishi, Y Takahashi, M Taguchi, S Watanabe
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 110, A3, AMER GEOPHYSICAL UNION, Mar. 2005, [Peer-reviewed]
English, Scientific journal, [1] Interplanetary hydrogen atoms that penetrate into the heliosphere are illuminated by enhanced hydrogen Lyman alpha emission from solar active regions. Using the data obtained by the Solar Wind Anisotropies ( SWAN) instrument on board the Solar and Heliospheric Observatory (SOHO), Bertaux et al. ( 2000) proposed a new method for earlier detection and monitoring of solar active regions on the far-side hemisphere. However, a quantitative relationship between the sky map of interplanetary Lyman alpha intensity and the enhanced emission from a solar active region was not discussed. Here, we analyze the interplanetary Lyman alpha intensity data obtained by the Ultraviolet Imaging Spectrometer (UVS) on board the Nozomi spacecraft. We develop a method to map the distribution of interplanetary Lyman alpha intensity into the Carrington coordinate system by assuming an interplanetary hydrogen screen at the location of maximum volume emission rate. Analysis period is from January 2000 to March 2000 near solar maximum. The solar activity during this analysis period is much higher as compared with the case study by Bertaux et al. ( 2000). The sky map of the Lyman alpha emission obtained by the UVS is shown to exhibit a high correlation with the solar extreme ultraviolet (EUV) intensity map obtained by the EUV Imaging Telescope (EIT) on board the SOHO satellite. The highest value of two-dimensional correlation coefficient is 0.80. An observed change in the periodicity of interplanetary Lyman alpha intensity is in good agreement with the growth of an active region on the Sun. It has been also confirmed that the far-side observations of UVS detected the growth of an active region in advance. This case study demonstrates that the location and intensity variation of activity on the far side of the Sun can be detected by far-side measurements of interplanetary Lyman alpha emission intensity. It is thus concluded that the developed method contributes to space weather forecasting on a scale of 2 weeks.

ELF sferic evidence for in-cloud discharge activity producing sprites
A Ohkubo, H Fukunishi, Y Takahashi, T Adachi
GEOPHYSICAL RESEARCH LETTERS, 32, 4, AMER GEOPHYSICAL UNION, Feb. 2005, [Peer-reviewed]
English, Scientific journal, Sprite luminosities produced by winter lightning in Japan were found to be associated with simultaneous occurrences of clusters of radio atmospherics as observed in the VLF range, suggesting an in- cloud discharge activity. Concurrent ELF data show transient perturbations, indicating continuous charge transfer in causative lightning. These data provide the first evidence that an incloud discharge activity plays an important role in the generation mechanism of sprites. Citation: Ohkubo, A., H. Fukunishi, Y. Takahashi, and T. Adachi ( 2005), VLF/ ELF sferic evidence for in- cloud discharge activity producing sprites.

Global measurement of lightning-associated transient luminous events (TLEs) from space
Sato, M, T. Ebisuzaki, Y. Takizawa, Y. Kawasaki, N. Sakaki, M. Bertaina, H.M. Shimizu, Y. Takahashi, T. Adachi
International Journal of Modern Physics A, 20, 29, 6903, 6905, 2005, [Peer-reviewed]
English, Scientific journal

Roles of the EMP and QE field in the generation of columniform sprites
Adachi, T, H. Fukunishi, Y. Takahashi, M. Sato
Geophys. Res. Lett., 31, 4, L04107, Feb. 2004, [Peer-reviewed]
English, Scientific journal

Energy estimation of electrons producing sprite halos using array photometer data
R Miyasato, H Fukunishi, Y Takahashi, MJ Taylor
JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS, 65, 5, 573, 581, PERGAMON-ELSEVIER SCIENCE LTD, Mar. 2003, [Peer-reviewed]
English, Scientific journal, Sprite halos are brief diffuse glows with an average duration of similar to1 ms occurring at altitudes from 70 to 85 km preceding the development of sprite streamers. Their horizontal scale is similar to50-100 km and they move downward as if focusing into the center. To investigate the energies of electrons producing sprite halos and their spatial and temporal variations, we analyzed photometric and CCD imaging data recorded at Yucca Ridge Field Station, Colorado, USA, during the Sprites'99 campaign. We estimated the electron energies from the intensity ratios of blue (350-500 nm) to red (560-800 nm) emissions captured separately by two array photometers on the assumption that the electron energy distribution is given by the Maxwell-Boltzmann or Druyvesteyn distribution. It is found that the electron energies reach their peaks preceding the luminosity peaks of the red emission (mostly due to the N-2 first positive and the N-2(+) Meinel band systems), exhibiting energy increases in the lower part of the sprite halo. The estimated peak electron energies are in the range 6-23 and 7-16 cV for the assumed Maxwell-Boltzmann and Druyvesteyn distribution, respectively. These results suggest that more energetic processes occur at the initiation of the sprite halo, particularly in its lower part. Nevertheless, the estimated values of electron energies Should be interpreted as a measure of the energetic processes producing sprite halos, represented by the equilibrium temperatures, since the real electron energy distributions would be undoubtedly deviated from the equilibrium states due to additional high-energy tails produced by the thermal runaway electron mechanism. (C) 2003 Elsevier Science Ltd. All rights reserved.

Activities of sprites and elves in the winter season, Japan
Y Takahashi, R Miyasato, T Adachi, K Adachi, M Sera, A Uchida, H Fukunishi
JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS, 65, 5, 551, 560, PERGAMON-ELSEVIER SCIENCE LTD, Mar. 2003, [Peer-reviewed]
English, Scientific journal, Sprites and elves observation has been carried out in three winter seasons in Japan since December 1998. Thirtyfive sprites' features have been imaged with CCD cameras and 95 optical emission from elves have been captured with hi-speed array photometers. The number of events observed on a night is dependent on the occurrence of intense cloud to ground lightning activity and cloud condition above the observation site. Most of the sprites/elves are directly associated with storms produced by a cold front passing over Japan. It is found that sprites/elves appear not only in the west coast of Japan but also above the Pacific Ocean. The average vertical length of winter sprites in the west cost is shorter than that of summer sprites in the US by about a factor of 2. The altitude of the causative thunderstorm for winter sprites and elves is comparatively lower than that of the summer events in the US and the horizontal width of the cloud is sometimes smaller than 30 km. The sprites' detection in winter in Japan suggests the possibility of winter sprite occurrence in Scandinavia and/or Israel where the climate condition is similar to Japan. (C) 2003 Elsevier Science Ltd. All rights reserved.

Effects of maturational age of porcine oocytes on the induction of activation and development in vitro following somatic cell nuclear transfer(Theriogenology)
IKEDA K., TAKAHASHI Y.
The journal of veterinary medical science, 63, 9, 1003, 1008, Japanese Society of Veterinary Science, 25 Aug. 2001
Japanese, To determine the effect of maturational age of porcine oocytes on the induction of activation and development following nuclear transfer, we investigated maturation rate and efficacy of oocyte activation treatment with an electrical stimulus(ES)and cycloheximide(CHX)at various timing of maturation culture. Most oocytes developed to the metaphase II(MII)stage after 32 hr of maturation culture. Both in newly matured(32 and 36 hr of age)and MII-arrested(42 and 48 hr of age)oocytes, ES followed by exposure to CHX for 6 hr caused higher rates of pronuclear formation than ES alone. Effect of maturational age of oocytes on the development of parthenotes activated with ES and CHX was then examined. The highest percentage of parthenotes developed to blastocysts was obtained when ES was added at 42 hr of culture. Finally, newly matured(33 hr of age)and MII-arrested oocytes(44 hr of age)were enucleated, fused with serum-starved pig fetal fibroblasts and activated with ES and CHX around suitable timing(39 to 40 hr of age)or later(50 to 51 hr of age), respectively. The frequencies of cleavage(58.8%)and blastocyst formation(13.6%)of newly matured oocytes were significantly(P<0.05)higher than those of MII-arrested oocytes(38.9 and 1.8%, respectively). These results demonstrated that the development of porcine nuclear transfer embryos can be improved by using complete matured oocytes as cytoplasts and activation treatment with ES followed by CHX treatment.

The dynamics of the proton aurora in auroral breakup events　　　　　　　　　　　　　　　
Takahashi, Y, H. Fukunishi
J. Geophys. Res., 106, 45, 63, 2001, [Peer-reviewed]

Global lightning acquisition system installed
Füllekrug, M, S. Constable, G. Heinson, M. Sato, Y. Takahashi, C. Price, E. Williams
EOS, 81, 333, Jul. 2000, [Peer-reviewed]
English, Scientific journal

Ultraviolet imaging spectrometer (UVS) experiment on board the NOZOMI spacecraft:Instrumentation and initial results
Taguchi M., Fukunishi H., Watanabe S., Okano S., Takahashi Y., Kawahara T. D.
Journal of geomagnetism and geoelectricity, 52, 1, 49, 60, The Seismological Society of Japan, Society of Geomagnetism and Earth, Planetary and Space Sciences, The Volcanological Society of Japan , The Geodetic Society of Japan , The Japanese Society for Planetary Sciences, 2000
English, An ultraviolet imaging spectrometer (UVS) on board the PLANET-B (NOZOMI) spacecraft has been developed. The UVS instrument consists of a grating spectrometer (UVS-G), an absorption cell photometer (UVS-P) and an electronics unit (UVS-E). The UVS-G features a flat-field type spectrometer measuring emissions in the FUV and MUV range between 110 nm and 310 nm with a spectral resolution of 2-3 nm. The UVS-P is a photometer separately detecting hydrogen (H) and deuterium (D) Lyman α emissions by the absorption cell technique. They take images using the spin and orbital motion of the spacecraft. The major scientific objectives of the UVS experiment at Mars and the characteristics of the UVS are described. The MUV spectra of geocoronal and interplanetary Lyman α emissions and lunar images taken at wavelength of hydrogen Lyman α and the background at 170 nm are presented as representative examples of the UVS observations during the Earth orbiting phase and the Mars transfer phase.

Ground-based observation of ULF transients excited by strong lightning discharges producing elves and sprites
Fukunishi, H, Y. Takahashi, M. Sato, A. Shono, M. Fujito, Y. Watanabe
Geophys. Res. Lett., 23, 2973, 2976, Dec. 1997, [Peer-reviewed]
English, Scientific journal

Elves: Lightning-induced transient luminous events in the lower ionosphere
H Fukunishi, Y Takahashi, M Kubota, K Sakanoi, US Inan, WA Lyons
GEOPHYSICAL RESEARCH LETTERS, 23, 16, 2157, 2160, AMER GEOPHYSICAL UNION, Aug. 1996, [Peer-reviewed]
English, Scientific journal, Observations of optical phenomena at high altitude above thunderstorms using a multichannel high-speed photometer and image intensified CCD cameras were carried out at Yucca. Ridge Field Station (40 degrees 40' N, 104 degrees 56' W), Colorado as part of the SPRITES'95 campaign from 15 June to August 6, 1995. These new measurements indicate that diffuse optical flashes with a duration of < 1 ms and a horizontal scale of similar to 100-300 km occur al 75-105 km altitude in the lower ionosphere just after the onset of cloud-to-ground lightning discharges, but preceding the onset of sprites. Here we designate these events as elves to distinguish them from red sprites''. This finding is consistent with the production of diffuse optical emissions due to the heating of the lower ionosphere by electromagnetic pulses generated by lightning discharges as suggested by several authors.

Machine Learning Prediction of Precipitation in Metro Manila, Philippines
野田明羅, 高橋幸弘, 久保田尚之, 福井健一, 佐藤光輝, 日本地球惑星科学連合大会予稿集(Web), 2022, 2022

Machine Learning Prediction of Precipitation in Metro Manila, Philippines
野田明羅, 高橋幸弘, 久保田尚之, 福井健一, 佐藤光輝, 日本地球惑星科学連合大会予稿集(Web), 2021, 2021

VLF/LF帯標準電波を用いた太陽フレアによる下部電離圏変動に関する研究
山野辺晃大, 大矢浩代, 土屋史紀, 山下幸三, 高橋幸弘, 野崎憲朗, 塩川和夫, 中田裕之, 大気電気学会誌(Web), 15, 1, 2021

フィリピン・マニラ首都圏における多地点静電場観測よる雷放電の3次元位置と電荷量の推定
菅野将史, 高橋幸弘, 大矢浩代, 中田裕之, 佐藤光輝, 久保田尚之, Purwadi, 大気電気学会誌(Web), 15, 1, 2021

火山噴火に伴うLF/VLF帯標準電波の強度変動
丸山慶, 庄子聖人, 大野夏樹, 大矢浩代, 土屋史紀, 津川卓也, 西岡未知, 山下幸三, 高橋幸弘, 中田裕之, 鷹野敏明, 大気電気学会誌, 13, 1, 2020

Optical properties of intracloud and cloud-to-ground discharges derived from JEM-GLIMS lightning observations
K. Bandholnopparat, M. Sato, T. Adachi, T. Ushio, Y. Takahashi, Journal of Atmospheric and Solar-Terrestrial Physics, 189, 87, 97, 01 Aug. 2019
© 2019 Elsevier Ltd We developed a new method to distinguish the lightning discharge type using lightning data obtained by JEM-GLIMS spaced-based mission and ground-based lightning network that are JLDN, NLDN, WWLLN, and GEON. As a first step, we selected 1057 lightning events detected by the JEM-GLIMS cameras (LSI) and spectrophotometers (PH) in 2014. Then, we compared the JEM-GLIMS optical data to the ground-based lightning data in order to check the simultaneous detection of JEM-GLIMS lightning events by the ground-based lightning networks, and finally we identified the discharge type of the JEM-GLIMS lightning events. We succeed in identifying 941 simultaneous lightning events and found that 582, 93, and 266 lightning events were IC, +CG, and -CG discharges, respectively. As a next step, we calculated intensity ratios between blue and red PH channels, i.e., 337nm/762 nm, 316nm/762 nm, 392nm/762 nm, 337nm/(599–900 nm), 316nm/(599–900 nm), and 392nm/(599–900 nm) for the 941 lightning events in order to specify the optical characteristics of IC, +CG, and -CG discharges. It is found that the PH intensity ratio of +CG discharges is the highest and that the PH intensity ratio of IC and -CG discharges is smaller than that of +CG discharge. We also found that the characteristics of the LSI intensity ratio are almost comparable to those of the PH intensity ratio. As the differences of the 337nm/762 nm, 337nm/(599–900 nm), and 392nm/(599–900 nm) ratio of IC, +CG, and -CG discharges are relatively large, these three ratios are a useful proxy for classifying the discharge types for additional 7349 lightning events detected by JEM-GLIMS in order to estimate the global ratio between IC and CG discharges (Z ratio).

Global distributions of lightning electrical energy estimated by optical observations from International Space Station
R. Kitamura, Y. Hobara, M. Sato, Y. Takahashi, T. Adachi, T. Ushio, M. Suzuki, 2019 URSI Asia-Pacific Radio Science Conference, AP-RASC 2019, 01 Mar. 2019
© 2019 URSI. All rights reserved. Recent study by [1] demonstrates the remarkable similarity between the time series of lightning optical irradiance observed by high speed photometric observations in GLIMS (Global LIghtning and sprite MeasurementS on JEMEF) mission installed in the International Space Station (ISS) and current moment change estimated by groundbased ELF magnetic field measurement based on 169 lightning strokes around Japan, which also indicates the high correlation between integrated irradiance and charge moment change (Qds).

Initial In-orbit Results of MicroDragon
平松崇, 山浦秀作, 戸梶歩, 白坂成功, 鶴田佳宏, 青柳賢英, 松本健, 中須賀真一, 栗原純一, 高橋幸弘, 桑原聡文, 坂本祐二, 吉田和哉, 増井博一, KIM Sang-kyun, 奥山圭一, CHO Mengu, ANH Tuan Pham, 宇宙科学技術連合講演会講演集(CD-ROM), 63rd, 2019

超小型衛星RISESAT搭載の海洋観測カメラによる沿岸域観測
齊藤誠一, 平田貴文, ALABIA Irene, 平譯享, 平譯享, 栗原純一, 高橋幸弘, 坂本祐二, 桑原聡文, 藤田伸哉, 羽生浩介, 村田悠, SAKAL Morokot, 冨尾蓮花, 佐藤悠司, LEE Ming-An, 望月貫一郎, 高橋文宏, 村上浩, 日本海洋学会大会講演要旨集, 2019, 2019

Road to the first star : Venus orbiter from Japan(33)Lightning hunt in Venus, to be continued
高橋 幸弘, 今井 正尭, 佐藤 光輝, 遊・星・人 = Planetary people : 日本惑星科学会誌, 27, 1, 43, 45, Mar. 2018
日本惑星科学会, Japanese

ドローンの現在地点 ドローンを活用したリモートセンシングによる営農支援技術~「精密農業」の最前線~
栗原純一, 石田哲朗, 高橋幸弘, 電波技術協会報FORN, 323, 2018

Operation results and international collaborations on 50-kg microsatellite DIWATA-1 using satellite deployment service of International Space Station
坂本祐二, 桑原聡文, 吉田和哉, 石田哲朗, 栗原純一, 高橋幸弘, 宇宙科学技術連合講演会講演集(CD-ROM), 62nd, 2018

Rice growth monitoring using UAV-based hyperspectral remote sensing
栗原純一, 石田哲朗, 高橋幸弘, 長田亨, 日本リモートセンシング学会学術講演会論文集(CD-ROM), 65th, 2018

惑星大気対流構造の解明にむけた雷放電探査観測計画
佐藤光輝, 高橋幸弘, 春山純一, 今井正尭, 日本気象学会大会講演予稿集, 114, 2018

関東圏VLF帯電界計測網による雷監視の性能評価
山下幸三, 岩崎博之, 大矢浩代, 高橋幸弘, 大気電気学会誌, 12, 1, 2018

火山噴火後のLF/VLF帯標準電波強度変動
丸山慶, 大矢浩代, 土屋史紀, 山下幸三, 高橋幸弘, 中田裕之, 鷹野敏明, 地球電磁気・地球惑星圏学会総会及び講演会(Web), 144th, 2018

ELF帯電波観測による雷放電の電荷量推定とダウンバーストの予測可能性について
清水千春, 佐藤光輝, 高橋幸弘, 本郷保二, 土屋史紀, 阿部修司, 吉川顕正, 大気電気学会誌, 11, 1, 59‐60, 15 Nov. 2017
Japanese

国際宇宙ステーションGLIMSミッションにより観測された雷発光強度を用いた雷の電気的特性導出に関する研究
鈴木克徳, 柿沼遠方, 芳原容英, 佐藤光輝, 高橋幸弘, 足立透, 牛尾知雄, 河崎善一郎, 森本健志, 山崎敦, 鈴木睦, LINSCOTT I. R, INAN U. S, 大気電気学会誌, 11, 1, 102‐103, 15 Nov. 2017
Japanese

Vegetation classification using UAV-based hyperspectral imaging
石田哲朗, 栗原純一, 高橋幸弘, 日本リモートセンシング学会学術講演会論文集(CD-ROM), 63rd, 2017

国際宇宙ステーションから観測された雷発光放射照度を用いた雷の電気的特性導出に関する研究
芳原容英, 鈴木克徳, 柿沼遠方, 佐藤光輝, 高橋幸弘, 足立透, 牛尾知雄, 河崎善一郎, 森本健志, 山崎敦, 鈴木睦, LINSCOTT Ivan, INAN Umran, 日本地球惑星科学連合大会予稿集(Web), 2017, ROMBUNNO.MIS05‐06 (WEB ONLY), 2017
Japanese

Latitudinal and Regional dependences of IC/CG ratio derived from JEM-GLIMS lightning observations
BANDHOLNOPPARAT Kittanapat, SATO Mitsuteru, TAKAHASHI Yukihiro, ADACHI Toru, USHIO Tomoo, 日本地球惑星科学連合大会予稿集(Web), 2017, ROMBUNNO.MIS05‐P03 (WEB ONLY), 2017
English

Initial Observations of Venus by Akatsuki
今村 剛, 中村 正人, 田口 真, 佐藤 毅彦, 岩上 直幹, 高橋 幸弘, 渡部 重十, 山崎 敦, 宇宙科学技術連合講演会講演集, 60, 4p, 06 Sep. 2016
日本航空宇宙学会, Japanese

Microsatellite constellation for the Earth and space environment
石田 哲朗, 高橋 幸弘, 栗原 純一, 長妻 努, 宇宙科学技術連合講演会講演集, 60, 3p, 06 Sep. 2016
日本航空宇宙学会, Japanese

High-Spatial Resolution Multi-Spectral Imaging with the HPT on the RISESAT Micro-Satellite
栗原 純一, 高橋 幸弘, 宇宙科学技術連合講演会講演集, 60, 3p, 06 Sep. 2016
日本航空宇宙学会, Japanese

Road to the first star : Venus orbiter from Japan(26)Arrival at Venus
Nakamura M., Yamazaki A., Taguchi M., Iwagami N., Satoh T., Planetary People, 25, 1, 4, 7, Mar. 2016
金星探査機「あかつき」は2015年12月に金星周回軌道に入った.日本初の惑星周回機の誕生である.観測機器の初期チェックは順調に進んでいる.中村プロジェクトマネージャーと観測機器担当者が所感を記す., The Japanese Society for Planetary Sciences, Japanese

The first Japan's planetary orbiter AKATSUKI and its scientific results
Masato Nakamura, Nobuaki Ishii, Takeshi Imamura, Takehiko Satoh, Takumi Abe, Chikako Hirose, Atsushi Yamazaki, Junichi Nakatsuka, Tsutomu Ichikawa, Tomoaki Toda, Hiroyuki Toyoda, Sumitaka Tachikawa, Yukio Kamata, Makoto Suzuki, Takao M. Sato, Shin Ya Murakami, Yukio Yamamoto, Naomoto Iwagami, Makoto Taguchi, Tesuya Fukuhara, Shigeto Watanabe, Yukihiro Takahashi, Munetaka Ueno, Manabu Yamada, George L. Hashimoto, Naru Hirata, Toru Kouyama, Kazunori Ogohara, Hiroki Ando, Koichiro Sugiyama, Hiroki Kashimura, Shoko Ohtsuki, Proceedings of the International Astronautical Congress, IAC, 01 Jan. 2016
Copyright © 2016 by the International Astronautical Federation (IAF). All rights reserved. Japan's Venus Climate Orbiter Akatsuki was proposed to ISAS (Institute of Space and Astronautical Science) in 2001 as an interplanetary mission. We made 5 cameras with narrow-band filters to image Venus at different wavelengths to track the cloud and minor components distribution at different heights to study the Venusian atmospheric dynamics in 3 dimension. It was launched on May 21st, 2010 and reached Venus on December 7th, 2010. With the thrust by the orbital maneuver engine, Akatsuki tried to go into the westward equatorial orbit around Venus with the 30 hours' orbital period, however it failed by the malfunction of the propulsion system. Later the spacecraft has been orbiting the sun for 5 years. On December 7th, 2015 Akatsuki met Venus again after the orbit control and Akatsuki was put into the westward equatorial orbit whose apoapsis is about 0.44 million km and orbital period of 14 days. Its main target is to shed light on the mechanism of the fast atmospheric circulation of Venus. The systematic imaging sequence by Akatsuki is advantageous for detecting meteorological phenomena with various temporal and spatial scales. We have five photometric sensors as mission instruments for imaging, which are 1 m-infrared camera (IR1), 2 m-infrared camera (IR2), ultra-violet imager (UVI), long-wave infrared camera (LIR), and lightning and airglow camera (LAC). These photometers except LIR have changeable filters in the optics to image in certain wavelengths. Akatsuki's long elliptical orbit around Venus is suitable for obtaining cloud-tracked wind vectors over a wide area continuously from high altitudes. With the observation, the characterizations of the meridional circulation, mid-latitude jets, and various wave activities are anticipated. The technical issues of Venus orbit insertion in 2015 and the scientific new results will be given in this paper.

スプライトを誘起した雷放電による上空電子密度擾乱の再現
佐藤光輝, 平木康隆, 足立透, 牛尾知雄, 森本健志, 菊池博史, 鈴木睦, 山崎敦, 高橋幸弘, 地球電磁気・地球惑星圏学会総会及び講演会(Web), 140th, ROMBUNNO.R005‐P18 (WEB ONLY), 2016
Japanese

JEM‐GLIMS直下視観測から同定したスプライトの水平空間分布と親雷放電との関係
佐藤光輝, 足立透, 佐藤剛志, 牛尾知雄, 森本健志, 鈴木睦, 山崎敦, 高橋幸弘, 日本地球惑星科学連合大会予稿集(Web), 2016, ROMBUNNO.PEM16‐12 (WEB ONLY), 2016
Japanese

雷放電・TLEsの全球発生分布および発生頻度と地方時間依存性
佐藤剛志, 佐藤光輝, 牛尾知雄, 森本健志, 足立透, 鈴木睦, 山崎敦, 高橋幸弘, 日本地球惑星科学連合大会予稿集(Web), 2016, ROMBUNNO.PEM16‐P04 (WEB ONLY), 2016
Japanese

Predictability of the downburst phenomena using the charge amounts of lightning discharges derived from ELF observation
SHIMIZU Chiharu, SATO Mitsuteru, TAKAHASHI Yukihiro, TSUCHIYA Fuminori, HONGO Yasuji, ABE Shuji, YOSHIKAWA Akimasa, 地球電磁気・地球惑星圏学会総会及び講演会(Web), 140th, ROMBUNNO.R005‐P02 (WEB ONLY), 2016
English

Horizontal distributions of sprites derived fromthe JEM-GLIMS nadir observations
M. Sato, M. Mihara, T. Adachi, T. Ushio, T. Morimoto, M. Kikuchi, H. Kikuchi, M. Suzuki, A. Yamazaki, Y. Takahashi, U. Inan, I. Linscott, R. Ishida, Y. Sakamoto, K. Yoshida, Y. Hobara, Journal of Geophysical Research, 121, 7, 3171, 3194, 01 Jan. 2016
© 2016. American Geophysical Union. All Rights Reserved. Global Lightning and Sprite Measurements on Japanese Experiment Module (JEM-GLIMS) started the nadir observations of lightning discharges and transient luminous events (TLEs) from the International Space Station (ISS) since November 2012. In the nadir observations, JEM-GLIMS optical instruments have to simultaneously detect incomparably intense lightning emissions and weak TLE emissions. To distinguish TLEs, especially sprite events, from lightning events, combined data analytical methods are adopted: (1) a subtraction of the wideband camera image from the narrowband camera image, (2) a calculation of the intensity ratio between different photometer channels, and (3) an estimation of the polarization and charge moment changes for the TLE-producing lightning discharges. We succeeded in identifying numbers of sprite events using the combined analytical methods, and here we report three sprite events detected by JEM-GLIMS as a case study. In the subtracted images, sprite emissions are located over the area of the sprite-producing lightning emissions. However, these sprites and sprite-producing lightning discharges did not occur at the nadir point of the ISS. For this reason, the geometry conversion of the sprite and sprite-producing lightning emissions as observed from the point just over the sprite-producing lightning discharges is performed. In the geometry-converted images, the locations of the sprite emissions are clearly displaced by 8-20 km from the peak positions of the sprite-producing lightning emissions. Thus, the first quantitative spatial distributions of sprites and sprite-producing lightning discharges from the JEM-GLIMS nadir observations are revealed.

Development of low-cost meteorological measurement system for hyper-dense observation of poor-visibility occurred by snowstorm
Kobayashi Yui, Watanabe Kyoya, Imai Masataka, Watanabe Kensuke, Naruse Nobuyasu, Takahashi Yukihiro, Nemoto Masaki, Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research, 2016, 0, 2016
The Japanese Society of Snow and Ice / Japan Society for Snow Engineering, Japanese

B-4-16 Initial Results of Lightning Observation in the Kanto region Based on Electromagnetic Measurement in ELF and VLF range
Yamashita Kozo, Takahashi Yukihiro, Proceedings of the Society Conference of IEICE, 2015, 1, 229, 229, 25 Aug. 2015
The Institute of Electronics, Information and Communication Engineers, Japanese

Application of infrasound observation to the future exploration project on the Martian surface
山本 真行, 高橋 幸弘, 佐藤 光輝, 月刊地球, 37, 8, 334, 339, Aug. 2015
海洋出版, Japanese

若手研究者を中心とした研究・技術開発の取り組み 高品位分光イメージングを実現可能にする液晶波長可変フィルタ
若生 一広, 栗原 純一, 高橋 幸弘, 電気評論, 100, 8, 73, 76, Aug. 2015
電気評論社, Japanese

国際宇宙ステーションGLIMSミッションにより観測されたホイスラを用いた電離層F層の電子密度推定
鈴木克徳, 柿沼遠方, 芳原容英, LINSCOTT I.R, INAN U.S, 佐藤光輝, 高橋幸弘, 牛尾知雄, 河崎善一郎, 森本健志, 山崎敦, 鈴木睦, 大気電気学会誌, 9, 1, 92, 93, 20 Apr. 2015
Japanese

JUICE搭載多バンド分光カメラ「JANUS」ミッションII
春山純一, 高橋幸弘, 佐藤光輝, 日本惑星科学会秋季講演会予稿集(Web), 2015, 2015

D311 国際宇宙ステーションからの雷放電と高高度発光現象の観測(降水システムIII,一般口頭発表)
牛尾 知雄, 佐藤 光輝, 鈴木 睦, 森本 健志, 菊池 博史, 菊池 雅行, 足立 透, 山崎 敦, 高橋 幸弘, Inan U., Lhscott I., 石田 良平, 坂本 祐二, 吉田 和哉, 芳原 容英, 阿部 琢己, 中村 正人, 織田 裕久, 大会講演予講集, 108, 380, 380, 2015
日本気象学会, Japanese

C307 Toward lightning observation in Venus with LAC on Akatsuki spacecraft
Takahashi Yukihiro, 大会講演予講集, 108, 360, 360, 2015
日本気象学会, English

惑星観測を目指した極周回成層圏テレスコープFUJINの開発
前田惇徳, 田口真, 荘司泰弘, 中野壽彦, 今井正尭, 合田雄哉, 高橋幸弘, 渡辺誠, 吉田和哉, 坂本祐二, 地球電磁気・地球惑星圏学会総会及び講演会予稿集(CD-ROM), 138th, 2015

ELF帯・VLF帯電磁界計測に基づいた東南アジア落雷分布の導出
山下幸三, 高橋幸弘, 大矢浩代, 土屋史紀, 電子情報通信学会大会講演論文集(CD-ROM), 2015, 2015

国際宇宙ステーションGLIMSミッションにより観測された雷発光とホイスラを用いた電離層F層の電子密度推定
鈴木克徳, 柿沼遠方, 芳原容英, LINSCOTT Ivan, INAN Umran, 佐藤光輝, 高橋幸弘, 牛尾知雄, 河崎善一郎, 森本健志, 山崎敦, 鈴木睦, 日本地球惑星科学連合大会予稿集(Web), 2015, ROMBUNNO.PEM11‐12 (WEB ONLY), 2015
Japanese

O13-03 流星観測衛星S-CUBEのミッション紹介と開発進捗報告(口頭発表セッション13 ダスト・探査I,口頭発表)
石丸 亮, 坂本 祐二, 小林 正規, 郷内 稔也, 藤田 伸哉, 千秋 博紀, 和田 浩二, 石橋 高, 黒澤 耕介, 山田 学, 阿部 新助, 吉田 和哉, 佐藤 光輝, 高橋 幸弘, 松井 孝典, 日本惑星科学会秋期講演会予稿集, 2014, "O13, 03", 10 Sep. 2014
日本惑星科学会, Japanese

P1-04 ピリカ望遠鏡およびVMC/VEXを用いた紫外撮像による金星スーパーローテーション周期とその時間発展の観測(ポスターセッション1,ポスター発表)
今井 正尭, 高橋 幸弘, 渡部 重十, 渡邊 誠, 日本惑星科学会秋期講演会予稿集, 2014, "P1, 04", 10 Sep. 2014
日本惑星科学会, Japanese

P2-31 JUICE搭載多バンド分光カメラ「JANUS」ミッション(ポスターセッション2,ポスター発表)
春山 純一, 高橋 幸弘, 佐藤 光輝, 日本惑星科学会秋期講演会予稿集, 2014, "P2, 31", 10 Sep. 2014
日本惑星科学会, Japanese

Observation of Jovian atmosphere and satellites with JANUS onboard JUICE
Takahashi Yukihiro, Haruyama Jun-ichi, Sato Mitsuteru, Proceedings of the ISAS Lunar and Planetary Symposium, 46, 3p, 05 Aug. 2014
Institute of Space and Astronautical Science, JAXA ; [2006]-, Japanese

Observations of discharge phenomena in the Martian atmosphere using electromagnetic and acoustic wave detectors
Sato Mitsuteru, Yamamoto Masayuki, Ishisaka Keigo, Takahashi Yukihiro, Ogohara Kazunori, Kamogawa Masashi, Miyamoto Hideaki, Abe Takumi, 第47回月・惑星シンポジウム = Proceedings of the 47th ISAS Lunar and Planetary Symposium, Aug. 2014
47th ISAS Lunar and Planetary Symposium (August 4-6, 2014. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS), Japanese

JEM‐GLIMSによるTLEsの光学観測―スプライト,エルブス観測例
佐藤光輝, 三原正大, 高橋幸弘, 足立透, 牛尾知尾, 森本健志, 鈴木睦, 山崎敦, 菊池雅行, INAN U, LINSCOTT I, 大気電気学会誌, 8, 1, 37, 18 Apr. 2014
Japanese

超小型衛星RISING-2搭載 マルチスペクトル望遠鏡 (特集 広がりを見せる衛星利用)
栗原 純一, 高橋 幸弘, 武山 芸英, O plus E : Optics・Electronics, 36, 4, 398, 401, Apr. 2014
アドコム・メディア, Japanese

Development of the Stratospheric Telescope for Observations of Planets - FUJIN-1 - and Evaluation of the Pointing Control System
SHOJI Yasuhiro, TAGUCHI Makoto, NAKANO Toshihiko, MAEDA Atsunori, TAKAHASHI Yukihiro, IMAI Masataka, NAKAMOTO Junpei, WATANABE Makoto, GODA Yuya, KAWAHARA Takeshi, YOSHIDA Kazuya, SAKAMOTO Yuji, JAXA research and development report, 13, 13-011, 87, 105, Mar. 2014
Seeing is the most important condition for high spatial resolution optical imaging by a ground-based telescope. The stable wind and low atmospheric density in the stratosphere provide ideal environment for optical observations of celestial objects. Taking advantages of the stratospheric environment even a small telescope with a sub-meter diameter main mirror can realize high spatial resolution imaging comparable to those by huge ground-based telescopes with a several-meter diameter. The circumpolar balloon-borne telescope, FUJIN, is a telescope floating in the polar stratosphere for optical observations of planets. Since the FUJIN was proposed in 2002, the flight system has been developed. The first flight test was conducted in 2009 to be failed due to hung-up of the onboard CPU. Improvement and further development has been continued, and then the FUJIN-1 flight model was rolled out in 2013. Unfortunately the flight experiment in 2013 was canceled due to the bad wind condition and some troubles in the balloon control system, respectively. However the functions of the FUJIN-1 were evaluated in the ground tests, and the flight model stood by as`flight ready.'In the tests the pointing control system of the telescope, which is the key mechanism for the FUJIN-1, was tested and evaluated to be capable of suppressing the pointing error within 0.4"(σ) which is smaller than the diffraction limit of the FUJIN-1 main telescope. From these results it has been decided that the development of the FUJIN-1 has been completed, and the development of the FUJIN-2, the flight system for longer flight duration in the northern polar region has been started. In this article the outline of the FUJIN project, the FUJIN-1 flight system and the ground test results of the pointing control functionality are introduced., Japan Aerospace Exploration Agency, Japanese

3.4 Cloud Variation with 27-day Periodicity and Solar Activities(3. Solar Activity and Terrestrial Environmental Change,Space Climatology)
TAKAHASHI Yukihiro, Journal of plasma and fusion research, 90, 2, 128, 131, 25 Feb. 2014
最近,太陽自転周期である27日程度の大気変動がみつかっている.ここでは特に西太平洋における雲変動に焦点を当てて紹介する.従来,11年周期についての調査は多くなされてきたが,それらは振幅が小さく,測定誤差の問題が指摘されているが,1ヶ月程度の周期変動は振幅が数10%を超えることもある.本節では,全球の積乱雲活動の指標であるシューマン共鳴現象と,衛星から観測される雲の変動が,共に太陽極大期のみ27日の周期性を示すことを紹介する.また,太陽振幅ではなく,周期が11年周期の太陽活動に関連していることを指摘し,それがエルニーニョなどより長い時間変動に影響している可能性を議論する., The Japan Society of Plasma Science and Nuclear Fusion Research, Japanese

4. Atmospheric Electricity : a Global Circuit Model(Space Climatology)
TAKAHASHI Yukihiro, Journal of plasma and fusion research, 90, 2, 137, 140, 25 Feb. 2014
積乱雲による発電を駆動源とし,地面と電離圏が成す巨大な球殻コンデンサーを基本構造とし,磁気圏・電離圏電流とも結合している可能性のある地球規模の電流回路-全地球回路(グローバルサーキット)-は,その仮説提唱から80年以上経つ今も十分定量的な理解に至っていない.しかし,その回路で運ばれるイオンや電場は,雲の生成・発達・消滅や雲頂高度に作用し,気候変動にも関与している可能性が指摘されている., The Japan Society of Plasma Science and Nuclear Fusion Research, Japanese

火星ローバー搭載電磁波・音波計測による火星ダスト環境下放電観測の検討
山本真行, 佐藤光輝, 高橋幸弘, 石坂圭吾, 小郷原一智, 鴨川仁, 宮本英昭, 阿部琢美, 宇宙科学技術連合講演会講演集(CD-ROM), 58th, 2014

P320 衛星光学観測に基づく雷放電特性の導出(ポスターセッション)
足立 透, 佐藤 光輝, 牛尾 知雄, 山崎 敦, 鈴木 睦, 菊池 雅行, 高橋 幸弘, Inan Umran, Linscott Ivan, 芳原 容英, Cohen M. B., Lu G., Cummer S. A., Hsu R. R., Chen A. B., Frey H. U., 大会講演予講集, 105, 296, 296, 2014
日本気象学会, Japanese

惑星観測を目指した極周回成層圏望遠鏡FUJIN
前田惇徳, 田口真, 吉田和哉, 坂本祐二, 中野壽彦, 荘司泰弘, 高橋幸弘, 仲本純平, 今井正尭, 渡辺誠, 合田雄哉, 地球電磁気・地球惑星圏学会総会及び講演会予稿集(CD-ROM), 136th, 2014

超小型地球観測衛星RISING‐2の開発および初期運用成果
坂本祐二, 杉村伸雄, 冨岡義弘, 桑原聡文, 吉田和哉, 栗原純一, 福原哲哉, 高橋幸弘, 宇宙科学技術連合講演会講演集(CD-ROM), 58th, ROMBUNNO.1K07, 2014
Japanese

P3-30 ピリカ望遠鏡とVMCによる金星の同時紫外測光の手法開発とスーパーローテーション周期の持つ寿命推定(ポスターセッション3,ポスター発表)
今井 正尭, 高橋 幸弘, 渡部 重十, 渡邊 誠, 日本惑星科学会秋期講演会予稿集, 2013, "P3, 30", 20 Nov. 2013
日本惑星科学会, Japanese

Application of Microsatellite to Space Science
栗原 純一, 高橋 幸弘, 桑原 総文, 宇宙科学技術連合講演会講演集, 57, 4p, 09 Oct. 2013
日本航空宇宙学会, Japanese

Construction of Lightning Observation Network in the Kanto region Based on Electromagnetic Measurement in ELF and VLF range
Yamashita Kozo, Takahashi Yukihiro, Matsumoto Jun, Hamada Jun-ichi, Proceedings of the Society Conference of IEICE, 2013, 1, 50, 50, 03 Sep. 2013
The Institute of Electronics, Information and Communication Engineers, Japanese

ほどよし二号の開発状況
桑原聡文, 坂本祐二, 吉田和哉, 栗原純一, 高橋幸弘, 高田淳史, 山川宏, 宇宙科学技術連合講演会講演集(CD-ROM), 57th, 2013

B117 関東地方におけるVLF帯雷電磁波観測網の構築と落雷規模の推定(竜巻・雷,口頭発表)
工藤 剛史, 高橋 幸弘, 佐藤 光輝, 岩崎 博之, 長 康平, 大会講演予講集, 104, 78, 78, 2013
日本気象学会, Japanese

B118 JEM-GLIMSによる宇宙からの雷・超高層放電の多波長観測(竜巻・雷,口頭発表)
足立 透, 佐藤 光輝, 牛尾 知雄, 山崎 敦, 鈴木 睦, 菊池 雅行, 高橋 幸弘, Inan Umran, Linscott Ivan, 芳原 容英, 大会講演予講集, 104, 79, 79, 2013
日本気象学会, Japanese

国際宇宙ステーションからの雷放電と高高度発光現象の観測計画―初期観測結果―
佐藤光輝, 牛尾知雄, 森本健志, 足立透, 鈴木睦, 山崎敦, 菊池雅行, 高橋幸弘, INAN Umran, LINSCOTT Ivan, 芳原容英, 大気圏シンポジウム・講演集(Web), 27th, III-4 (WEB ONLY), 2013
Japanese

JEM‐GLIMSによる雷・TLEの天底観測:スプライト,エルブス観測例
佐藤光輝, 足立透, 牛尾知雄, 森本健志, 鈴木睦, 山崎敦, 菊池雅行, 高橋幸弘, INAN Umran, LINSCOTT Ivan, 芳原容英, 地球電磁気・地球惑星圏学会総会及び講演会予稿集(CD-ROM), 134th, ROMBUNNO.S001-07, 2013
Japanese

国際宇宙ステーションからの雷放電とスプライトの国際共同観測
牛尾 知雄, 森本 健志, 佐藤 光輝, 鈴木 睦, 山崎 敦, 芳原 容英, 菊地 雅行, 高橋 幸弘, INAN Umran, 石田 良平, 坂本 祐二, 吉田 和哉, 阿部 琢美, 河崎 善一郎, 大気電気学会誌 = / Society of Atmospheric Electricity of Japan, 6, 2, 15 Nov. 2012
Japanese

C167 土星大気の可視近赤外におけるスペクトル撮像観測(スペシャル・セッション「惑星大気科学の課題と将来の探査計画」,口頭発表)
濱本 昂, 高橋 幸弘, 渡辺 誠, 大会講演予講集, 102, 148, 148, 30 Sep. 2012
社団法人日本気象学会, Japanese

A report on a conference discussing the future of the Japanese Community for Planetary Sciences
KOBAYASHI N., TAKAHASHI Y., SUZUKI A., WADA K., Planetary People, 21, 3, 324, 329, 25 Sep. 2012
2012年7月24日,神戸大学惑星科学研究センター内の講義室にて「惑星科学の今後を考える会」なる催しが開かれた.本稿はその会議の参加記録であり,紹介である. 1992年に惑星科学会が発足して以来20年の歳月が流れた.その間,惑星探査,大型望遠鏡観測,大規模シミュレーション科学等の大型プロジェクトに関わる研究者も増え,拠点と呼ばれる組織も生まれてきた.本会では惑星科学コミュニティにおけるそうした拠点組織の持つ役割と課題を整理し,現状認識を深め,大型プロジェクト研究を推進できる力を持つコミュニティの今後のあり方について議論した., The Japanese Society for Planetary Sciences, Japanese

Preface
TAKAHASHI Y., Planetary People, 21, 3, 195, 195, 25 Sep. 2012
The Japanese Society for Planetary Sciences, Japanese

Preface
Takahashi Y, Planetary People, 21, 3, 25 Sep. 2012
The Japanese Society for Planetary Sciences, Japanese

Optical Lightning Detector on board Jovian Orbiter(Planetary exploration in a coming decade activity: Reports of 2nd stage)
Takahashi Y, Sato M, Fukuhara T, Kurihara J, Nakajima K, Planetary People, 21, 3, 224, 228, 25 Sep. 2012
近年,木星大気の大規模構造を決める力学や,大気組成を決める化学過程を理解する上で,積乱雲や雷放電観測の重要性が指摘されている.しかし,対流強度は雲頂高度など雲本体の観測のみからでは難しい.雷放電発光の強度,頻度,高度の情報はそれを補う優れた指標のひとつであるが,通常のカメラでは時間分解能が不十分で,積乱雲活動の定量的な評価は困難である.ここで提案する雷放電発光検出器"OLD"は,高速撮像・画像処理によって雷放電発光の頻度から対流活動強度を求め,また色情報から高度推定することを可能にする., The Japanese Society for Planetary Sciences, Japanese

B-4-16 Construction of Asian lightning observation network based on measurement of ELF and VLF sferics
Yamashita Kozo, Ohya Hiroyo, Tsuchiya Fuminori, Takahashi Yukihiro, Matsumoto Jun, Proceedings of the Society Conference of IEICE, 2012, 1, 28 Aug. 2012
The Institute of Electronics, Information and Communication Engineers, Japanese

Micro-Satellites for International Scientific Missions
YOSHIDA Kazuya, SAKAMOTO Yuji, KUWAHARA Toshinori, TAKAHASHI Yukihiro, 計測と制御 = Journal of the Society of Instrument and Control Engineers, 51, 5, 438, 443, 10 May 2012
計測自動制御学会, Japanese

日本の独自技術で拓く超小型衛星による次世代リモートセンシング
高橋 幸弘, 計測と制御 = Journal of the Society of Instrument and Control Engineers, 51, 5, 445, 448, 10 May 2012
計測自動制御学会, Japanese

Sensing Applications Using Micro-Satellites
KIMURA Shinichi, NAKASUKA Shinichi, GOUDA Naoteru, YAMAMOTO Masaya, IWASAKI Akira, KURAHARA Naomi, YOSHIDA Kazuya, TAKAHASHI Yukihiro, Journal of the Japan Society for Aeronautical and Space Sciences, 60, 4, 137, 148, 05 Apr. 2012
近年,従来の数トン級衛星ではなく,100〜500kgの「小型衛星」が世界各国の地図作成,安全保障,防災,都市計画,自然環境・気象観測,農産物の生産管理,科学調査等の様々な分野に利用され,また,大学・研究機関・企業等の宇宙利用のニーズが高まってきた.こうした状況に合わせ,日本航空宇宙学会誌では計測自動制御学会誌と共同特集企画として,主に超小型衛星の利用に焦点を当てた特集「小型衛星を用いたセンシングアプリケーション」を掲載することとした.日本航空宇宙学会誌では,計測自動制御学会の特集号に先立ち,その特集号にて掲載される内容をダイジェスト版として紹介する., The Japan Society for Aeronautical and Space Sciences, Japanese

P391 アジア海洋大陸近傍における雷放電活動とOLRの関係(ポスター・セッション)
三宮 佑介, 高橋 幸弘, 佐藤 光輝, 山下 幸三, 大会講演予講集, 102, 565, 565, 2012
日本気象学会, Japanese

太陽地球系科学の現状と科学課題 4:地球惑星圏における人類活動を支える知識基盤の構築
高橋幸弘, 吉川顕正, 山本衛, 地球電磁気・地球惑星圏学会総会及び講演会予稿集(CD-ROM), 132nd, 2012

北大ピリカ望遠鏡による金星観測計画
高橋幸弘, 福原哲哉, 濱本昂, 尾崎彰士, 渡辺誠, 田中培生, 大月祥子, 神山徹, 大気圏シンポジウム・講演集(Web), 26th, 2012

北大ピリカ望遠鏡による土星のスペクトル撮像
濱本昂, 高橋幸弘, 尾崎彰士, 渡辺誠, 大気圏シンポジウム・講演集(Web), 26th, 2012

極周回成層圏テレスコープによる惑星大気観測
田口真, 山元夢摘, 吉田和哉, 坂本祐二, 中野壽彦, 荘司泰弘, 高橋幸弘, 渡辺誠, 濱本昂, 今井正尭, 仲本純平, 日本天文学会年会講演予稿集, 2012, 2012

ほどよし2号機のミッションと開発状況
桑原聡文, 坂本祐二, 吉田和哉, 栗原純一, 高橋幸弘, 高田淳史, 山川宏, 宇宙科学技術連合講演会講演集(CD-ROM), 56th, ROMBUNNO.2M12, 2012
Japanese

C166 ピリカ望遠鏡による金星雲の循環周期観測(スペシャル・セッション「惑星大気科学の課題と将来の探査計画」,口頭発表)
今井 正尭, 高橋 幸弘, 渡辺 誠, 濱本 昂, 大会講演予講集, 102, 147, 147, 2012
日本気象学会, Japanese

Lightning and Sprite Imager (LSI) onboard JEM-GLIMS
Mitsuteru Sato, Yukihiro Takahashi, Masayuki Kikuchi, Makoto Suzuki, Atsushi Yamazaki, Tomoo Ushio, IEEJ Transactions on Fundamentals and Materials, 131, 12, 994, 999, 01 Dec. 2011
Lightning and Sprite Imager (LSI) is a science instrument of JEM-GLIMS to capture images of lightning discharges and upper atmospheric transient luminous events (TLEs), such as sprites, elves and blue jets. LSI consists of two CMOS cameras; one is a wide-band camera named LSI-1 that is equipped with an optical filter whose pass-band ranges from 765nm to 830nm, the other is a narrow-band camera named LSI-2 that is equipped with an optical filter whose transmittance centers at the wavelength of 762 nm and has band width of 14 nm. From the comparison of LSI-1 images with LSI-2 images the time evolution and spatial distribution of lightning discharges and TLEs can be identified. Since the telemetry speed provided for JEM-GLIMS is limited, LSI images will be acquired not continuously but intermittently according to the onboard event trigger logic. This trigger logic selects only the transient optical flashes caused by lightning discharges or TLEs effectively. © 2011 The Institute of Electrical Engineers of Japan., The Institute of Electrical Engineers of Japan, English

Six-channel spectrophotometers (PH) onboard JEM-GLIMS
Mitsuteru Sato, Yukihiro Takahashi, Makoto Suzuki, Atsushi Yamazaki, Tomoo Ushio, IEEJ Transactions on Fundamentals and Materials, 131, 12, 1000, 1005, 01 Dec. 2011
Six-channel spectrophotometers (PH) are the science instruments of JEM-GLIMS to measure absolute intensity of the emission originated from lightning discharges and upper atmospheric transient luminous events (TLEs). PH unit-1 (PH-U1) consists of four spectrophotometer channels named from PH1 to PH4, while PH unit-2 (PH-U2) two spectrophotometer channels named PH5 and PH6. Optical filters of these spectrophotometers are selected to detect TLE emission lines of N21PG, N22PG, N+21NG, and N2LBH. Since the bandwidth of the optical filter of PH2,3,5, and 6 is 10 nm and since PH1 measures NUV emission, photomultiplier tubes with high-voltage converters are used as a photon detector. To the contrary, PH4 uses a photodiode as a photon detector because the pass-band of the optical filter is enough wide to detect transient optical emission. Though PH does not equip spatial resolution, it can acquire light curve data with a high time resolution of 50 μs with a 12-bit resolution. Thus, the combinational analysis of PH data and Lightning and Sprite Imager (LSI) data, it is possible to clarify the relationship between TLEs and their parent lightning discharges, the occurrence condition of TLEs, and the energy of the electrons which excite TLE emission. © 2011 The Institute of Electrical Engineers of Japan., The Institute of Electrical Engineers of Japan, English

Advanced remote-sensing sensors for micro-satellite and their applications(Technical Session,ICSANE 2011(International Conference on Space, Aeronautical and Navigational Electronics 2011))
TAKAHASHI Yukihiro, FUKUHARA Tetsuya, KURIHARA Junichi, Technical report of IEICE. SANE, 111, 239, 33, 35, 10 Oct. 2011
New types of remote-sensing sensors for 50-kg class micro-satellite have been developed at Hokkaido University, a member of UNIFORM and Hodoyoshi projects promoted by Japanese government. In those sensors, advanced devices, materials or techniques, such as liquid crystal tunable filter, commercial-based bolometer array, zero-expansion ceramic mirror, grinding process for the ceramic mirror are applied for the first time. Also, in this presentation, applications of the sensors to remote-sensing of the Earth are introduced., The Institute of Electronics, Information and Communication Engineers, Japanese

S192025 Pre-Flight Verification for the Bus System Development of Earth Observation Microsatellite RISING-2
SAKAMOTO Yuji, KUWAHARA Toshinori, YOSHIDA Kazuya, TAKAHASHI Yukihiro, Mechanical Engineering Congress, Japan, 2011, "S192025, 1"-"S192025-3", 11 Sep. 2011
The development of 50-kg class microsatellite RISING-2 was started in July, 2009 by Tohoku Univ. and Hokkaido Univ. At the time of May, 2011, the fabrication and evaluation tests of engineering model (EM) and the fabrication of flight model (FM) were finished. The launch opportunity has been not decided yet. The satellite has a telescope with 10-cm diameter and 1-m focal length, and the resolution of image is 5 meters. It observes multi-spectrum images of cumulonimbus clouds using liquid crystal tunable filter as well as RGB color photos. Also, transient luminous events in upper atmosphere such as sprite are observed using CMOS sensors. This paper shows the final specifications of FM, and the verification tests of bus system., The Japan Society of Mechanical Engineers, Japanese

F3 Evaluation of Efficient Development Methods of 50-kg Microsatellites Based on SPRITE-SAT and RISING-2
Sakamoto Yuji, Kuwahara Toshinori, Yoshida Kazuya, Takahashi Yukihiro, スペース・エンジニアリング・コンファレンス講演論文集 : Space Engineering Conference, 2010, 19, "F3, 1"-"F3-6", 27 Jan. 2011
Tohoku University and Hokkaido University started the development of a new 50-kg microsatellite RISING-2 at July 2009. This satellite inherits the development technique of RISING (SPRITE-SAT) launched on January 2009. The progress is shown in this paper. Using a Cassegrain telescope with 10-cm diameter and 1-m focal length, earth surface is observed with 5-m resolution from 700-km-alt sun synchronous orbit. By 3-axis attitude stabilization using reaction wheels and star sensors, the designated area on earth surface can be observed. In addition to color images, multi-spectrum images of cumulonimbus are observed by using a liquid crystal tunable filter. As a secondary mission, transient luminous events such as sprite are observed, which is same mission as SPRITE-SAT., The Japan Society of Mechanical Engineers, Japanese

Overview of Venus orbiterAkatsuki
M. Nakamura, T. Imamura, N. Ishii, T. Abe, T. Satoh, M. Suzuki, M. Ueno, A. Yamazaki, N. Iwagami, S. Watanabe, M. Taguchi, T. Fukuhara, Y. Takahashi, M. Yamada, N. Hoshino, S. Ohtsuki, K. Uemizu, G. L. Hashimoto, M. Takagi, Y. Matsuda, K. Ogohara, N. Sato, Y. Kasaba, T. Kouyama, N. Hirata, R. Nakamura, Y. Yamamoto, N. Okada, T. Horinouchi, M. Yamamoto, Y. Hayashi, Earth, Planets and Space, 63, 5, 443, 457, 2011
The Akatsuki spacecraft of Japan was launched on May 21, 2010. The spacecraft planned to enter a Venusencircling near-equatorial orbit in December 7, 2010
however, the Venus orbit insertion maneuver has failed, and at present the spacecraft is orbiting the Sun. There is a possibility of conducting an orbit insertion maneuver again several years later. The main goal of the mission is to understand the Venusian atmospheric dynamics and cloud physics, with the explorations of the ground surface and the interplanetary dust also being the themes. The angular motion of the spacecraft is roughly synchronized with the zonal flow near the cloud base for roughly 20 hours centered at the apoapsis. Seen from this portion of the orbit, cloud features below the spacecraft continue to be observed over 20 hours, and thus the precise determination of atmospheric motions is possible. The onboard science instruments sense multiple height levels of the atmosphere to model the three-dimensional structure and dynamics. The lower clouds, the lower atmosphere and the surface are imaged by utilizing nearinfrared windows. The cloud top structure is mapped by using scattered ultraviolet radiation and thermal infrared radiation. Lightning discharge is searched for by high speed sampling of lightning flashes. Night airglow is observed at visible wavelengths. Radio occultation complements the imaging observations principally by determining the vertical temperature structure. Copyright © The Society of Geomagnetism and Earth Planetary and Space Sciences (SGEPSS)., Springer Berlin, English, Book review

土星巨大ストームの多波長分光撮像観測
濱本昂, 高橋幸弘, 渡辺誠, 渡部重十, 福原哲哉, 佐藤光輝, 地球電磁気・地球惑星圏学会総会及び講演会予稿集(CD-ROM), 130th, 2011

北海道大学1.6m光学赤外望遠鏡のファーストライト観測
渡辺誠, 高橋幸弘, 渡部重十, 佐藤光輝, 福原哲也, 濱本昂, 徂徠和夫, 中尾光, 田中培生, 館内謙, 関口朋彦, 日本天文学会年会講演予稿集, 2011, 2011

北大1.6m新望遠鏡カセグレン焦点に設置された近赤外線分光装置“NICE”
舘内謙, 田中培生, 山室智康, 川端拡信, 高橋英則, 渡部重十, 高橋幸弘, 佐藤光輝, 渡辺誠, 福原哲哉, 濱本昂, 日本天文学会年会講演予稿集, 2011, 2011

可視光マルチスペクトル撮像装置MSIの性能評価
渡辺誠, 高橋幸弘, 渡部重十, 佐藤光輝, 福原哲也, 濱本昂, 日本天文学会年会講演予稿集, 2011, 2011

超小型衛星用高機能リモセン機器の開発
高橋幸弘, 栗原純一, 宇宙科学技術連合講演会講演集(CD−ROM), 55th, ROMBUNNO.3S13, 2011
Japanese

Lightning and sprite observation from international space station
Tomoo Ushio, Mitsuteru Sato, Takeshi Morimoto, Makoto Suzuki, Hiroshi Kikuchi, Atsushi Yamazaki, Yukihiro Takahashi, Yasuhide Hobara, Umran Inan, Ivan Linscott, Yuji Sakamoto, Ryohei Ishida, Masavuki Kikuchi, Kazuya Yoshida, Zen Ichiro Kawasaki, IEEJ Transactions on Fundamentals and Materials, 131, 1, 16, 20, 2011
Lightning and sprite measurement sensors on the International Space Station (ISS) are introduced in this paper. Lightning is an electrical discharge which neutralizes the charge inside thunderstorm. In the early 1990s, optical transient luminous events (TLEs) occurring just above the thunderstorm were firstly reported by the US scientists and are associated with positive cloud-to-ground discharges with a large amount of charge. Though the luminous events so-called sprite, elves and jets have been investigated by numerous researchers all over the world based mainly on the ground observations, some important problems have not been fully understood yet such as generation mechanisms of columniform fine structure and horizontal offset of some sprites from the parent lightning discharges. In the JEM-GLIMS mission, observations from our synchronized sensors are going to shed light on above-mentioned unsolved problems regarding TLEs as well as causative lighting discharges. Our goals are (1) to detect and locate lightning and sprite within storm scale resolution over a large region of the Earth's surface along the orbital track of the ISS without any bias, (2) to clarify the generation mechanism of sprite, and (3) to identify the occurrence conditions of TLEs. © 2011 The Institute of Electrical Engineers of Japan., The Institute of Electrical Engineers of Japan, Japanese, Book review

Strategic study of lunar and planetary explorations in coming decade : Panel report on top sciences
Ohtani E., Kimura J., Takahashi Y., Nakajima K., Nakamoto T., Miyoshi Y., Kobayashi K., Yamagishi A., Namiki N., Kobayashi N., Demura H., Kuramoto K., Ohtsuki K., Imamura T., Terada N., Watanabe S., Arakawa M., Ito T., Yurimoto H., Watanabe J., Planetary People - The Japanese Society for Planetary Sciences, 20, 4, 349, 365, 2011
「月惑星探査の来たる10年」検討では第一段階で5つのパネルの各分野に於ける第一級の科学について議論した.そのとりまとめを報告する.地球型惑星固体探査パネルでは,月惑星内部構造の解明,年代学・物質科学の展開による月惑星進化の解明,固体部分と結合した表層環境の変動性の解明,が挙げられた.地球型惑星大気・磁気圏探査パネルは複数学会に跨がる学際性を考慮して,提案内容に学会間で齟齬が生じないように現在も摺り合わせを進めている.本稿では主たる対象天体を火星にしぼって第一級の科学を論じる.小天体パネルでは始原的・より未分化な天体への段階的な探査と,発見段階から理解段階へ進むための同一小天体の再探査が提案された.木星型惑星・氷衛星・系外惑星パネルは広範な科学テーマの中から,木星の大気と磁気圏探査,氷衛星でのハビタブル環境の探査,系外惑星でも生命存在可能環境と生命兆候の発見について具体的な議論を行った.アストロバイオロジーパネルでは現実的な近未来の目標として火星生命探査を,長期的な目標として氷衛星・小天体生命探査を目指した観測装置開発が検討された.これらのまとめを元に「月惑星探査の来たる10年」検討は2011年7月より第二段階に移行し,ミッション提案・観測機器提案の応募を受け付けた., The Japanese Society for Planetary Sciences, Japanese

Lightning and Sprite Observation from International Space Station
USHIO Tomoo, SATO Mitsuteru, MORIMOTO Takeshi, SUZUKI Makoto, KIKUCHI Hiroshi, YAMAZAKI Atsushi, TAKAHASHI Yukihiro, HOBARA Yasuhide, INAN Umran, ISHIDA Ryohei, KAWASAKI Zen-Ichiro, 電気学会研究会資料. EMC, 電磁環境研究会, 2010, 29, 1, 4, 01 Nov. 2010
Japanese

BI-1-3 Development and Evaluation for Fine Optical Pointing Control System Using Tip-Tilt Mirror
Yoshida Kazuya, Shoji Yasuhiro, Sakamoto Yuji, Taguchi Makoto, Takahashi Yukihiro, Proceedings of the IEICE General Conference, 2010, 1, "SS, 78"-"SS-79", 02 Mar. 2010
The Institute of Electronics, Information and Communication Engineers, Japanese

A balloon-borne telescope developed for remote sensing of planets from the polar stratosphere
TAGUCHI Makoto, SHOJI Yasuhiro, SAKAMOTO Yuji, YOSHIDA Kazuya, TAKAHASHI Yukihiro, TERAGUCHI Tomoko, OHNISHI Tomoya, BATTAZZO Steve, SATO Takao, HOSHINO Naoya, UNO Takeru, YOSHIMURA Atsushi, JAXA research and development report, 9, 53, 72, Mar. 2010
A long-term continuous observation is essential for studies of time-dependent phenomena of the planetary atmospheres and plasmas. A balloon-borne telescope system has been developed for remote sensing of the planets from the polar stratosphere. In this system, a Schmidt-Cassegrain telescope with a 300-mm clear aperture is mounted on a gondola whose attitude is controlled by control moment gyros, an active decoupling motor, and attitude sensors. The gondola can float in the stratosphere for periods in excess of 1 week. A pointing stability of 0.1"rms will be achieved by the cooperative operation of the following three-stage pointing devices: a gondola-attitude control system, twoaxis telescope gimbals for coarse guiding, and a tip/tilt mirror mount for guiding error correction. The first experiment of the balloon-borne telescope system was conducted on June 3, 2009 in Taikicho, Hokkaido targeting Venus. The balloon was launched at 4:10 JST and the system has been operating perfectly for two hours after launch. During the first level flight at an attitude of 14 km attitude control was activated. Oscillation of the azimuthal angle of the gondola was damped at an expected rate and the gondola was stabilized within an error of 1?rms for a several minutes. Unfortunately capture of Venus images by the telescope was aborted because of failure in the onboard computer occurred at two hours after launch. However, from the video signal from the Sun sensor azimuthal angular velocity of the free gondola is estimated to be 20°/min or slower. These results from the experiments including the ground-based tests suggest that the basic system concept of the balloon-borne telescope, especially the attitude control and tracking technology, is correct. A more robust and a dependable onboard computer is required for a future experiment., Japan Aerospace Exploration Agency, Japanese

B2 Progress Report and Future Plan of Microsatellite RISING Series
SAKAMOTO Yuji, YOSHIDA Kazuya, TAKAHASHI Yukihiro, スペース・エンジニアリング・コンファレンス講演論文集 : Space Engineering Conference, 2009, 18, 35, 39, 28 Jan. 2010
The microsatellite RISING(SPRITE-SAT) developed by Tohoku University was launched in January 2009. The former part of this paper shows the outline of mission and system design. The operation result of initial phase and the reason of serious trouble are introduced. On July 2009, our team initiated the development of second microsatellite named RISING-2. This satellite has a high precision telescope and reaction wheels. The outline of this new project is shown in the latter part., The Japan Society of Mechanical Engineers, Japanese

A209 国際宇宙ステーションからの雷放電と高高度発光現象の観測(GLIMS)(降水システムI,一般口頭発表)
牛尾 知雄, 森本 健志, 佐藤 光輝, 鈴木 睦, 山崎 敦, 芳原 容英, 菊地 雅行, 高橋 幸弘, Inan Umran, 石田 良平, 坂本 祐二, 吉田 和哉, 阿部 琢美, 河崎 善一郎, 大会講演予講集, 97, 52, 52, 2010
日本気象学会, Japanese

1.6m級光学反射望遠鏡を用いた「あかつき」との金星同時観測
福原哲哉, 高橋幸弘, 佐藤光輝, 渡部重十, 渡辺誠, 佐藤創我, 大気圏シンポジウム・講演集(Web), 24th, 2010

Road to the First Star No.9 : Observational strategy and performance tests of Lightning and Airglow Camera: LAC
Takahashi Yukihiro, Hoshino Naoya, Planetary People, 18, 4, 238, 241, 25 Dec. 2009
金星における世界初の雷放電観測専用機能と微弱大気光の検出能力を兼ね備えた雷・大気光カメラLACは,ハードウェアの製作・各種試験が完了し,実地観測に備えたパラメータ設定と詳細シーケンスの検討に入った.LACの科学的背景と目標,設計方針,これまで行った試験などについて紹介する., The Japanese Society for Planetary Sciences, Japanese

国際宇宙ステーションからの雷放電・スプライト観測計画 : JEM-GLIMSミッション
佐藤 光輝, 牛尾 知雄, 森本 健志, 高橋 幸弘, INAN Umran, 芳原 容英, 菊池 雅行, 鈴木 睦, 山崎 敦, 阿部 琢美, 吉田 和哉, 坂本 祐二, 奥山 圭一, 石田 良平, 河崎 善一郎, 大気電気学会誌 = / Society of Atmospheric Electricity of Japan, 3, 2, 60, 61, 30 Oct. 2009
Japanese

308 Exploration of Jupiter and Trojan Asteroids by EJSM
佐々木 晶, 藤本 正樹, 木村 淳, 高島 健, 矢野 創, 笠羽 康正, 高橋 幸弘, 川口 淳一郎, 川勝 康弘, 津田 雄一, 船瀬 龍, 森 治, 森本 睦子, 木星探査WG, Abstracts Fall Meeting of the Japanese Society for Planetary Sciences, 2009, 59, 59, 28 Sep. 2009
The Japanese Society for Planetary Sciences, Japanese

P315 1.6m光学反射望遠鏡を用いたPLANET-Cとの金星同時観測計画(ポスターセッション3)
福原 哲哉, 高橋 幸弘, 佐藤 光輝, 渡部 重十, 佐藤 創我, 渡邉 誠, 日本惑星科学会秋期講演会予稿集, 2009, 28 Sep. 2009
日本惑星科学会, Japanese

Surface geologic investigation by MELOS
SUGITA Seiji, MIYAMOTO Hideaki, TACHIBANA Shogo, OKADA Tatsuaki, DEMURA Hirohide, OHMORI Soichi, NAMIKI Noriyuki, TAKAHASHI Yukihiro, MIURA Yayoi, NAGAO Keisuke, MIKOUCHI Takeshi, SATOH Takehiko, Planetary people, 18, 2, 79, 83, 25 Jun. 2009
我々はこれまでの火星複合探査ワーキンググループの中で,MELOSの着陸機によってどのような火星表層探査を行うべきか,またどのような測定によって実現されるのか議論を行ってきた.本稿では,その議論で見えてきた火星着陸探査による表面探査の科学目標と搭載機器候補について解説する., The Japanese Society for Planetary Sciences, Japanese

Exploring the Martian meteorology and hydrology(Definition of Science Objectives for MELOS Mars Exploration)
Imamura Takeshi, Kasai Yasuko, Sagawa Hideo, Kuroda Takeshi, Satoh Takehiko, Ueno Munetaka, Suzuki Makoto, Takahashi Yukihiro, Takahashi Yoshiyuki, Hashimoto George L, Kuramoto Kiyoshi, Planetary People, 18, 2, 76, 78, 25 Jun. 2009
火星表層の水循環や気象学の理解を目的とする火星周回衛星の検討を進めている.可視〜赤外域での高解像度の分光撮像による水蒸気マッピングと大気力学場モニター,そしてサブミリ波サウンダーによる水蒸気やその他微量ガスの3次元分布の観測が,二つの柱である.着陸機による局地気象の直接観測や大気電気観測との連携についても検討中である., The Japanese Society for Planetary Sciences, Japanese

Transient Luminous Events in the Middle and Upper Atmosphere Associated with Lightning Activity
TAKAHASHI Yukihiro, Butsuri, 64, 5, 365, 372, 05 May 2009
Usual lightning is the discharge phenomenon between thundercloud and ground, and/or inside thundercloud. However, in 1989 a new type of discharge was found accidentally during camera test for other observational purpose, and named as sprites, which occur in the altitude range of 40-90km. Since the first discovery of sprites, several kinds of transient luminous events (TLEs) in the middle and upper atmosphere associated with thunderstorm activity have been found and investigated extensively both by observations, including spacecraft and ground-based measurements, and by numerical modeling. Regardless of such efforts, still we cannot explain even the fundamental mechanisms of the phenomena, although the standard models were proposed over 10 years ago. In this manuscript the latest progress of this field and future strategies in observation are introduced as well as a brief review of the research history with some episodes., The Physical Society of Japan (JPS), Japanese

30aSP-7 Recent progress and scope of TLEs and TGFs studies
Takahashi Yukihiro, Meeting abstracts of the Physical Society of Japan, 64, 1, 246, 246, 03 Mar. 2009
The Physical Society of Japan (JPS), Japanese

Latitudinal dependence of the solar wind density derived from remote sensing measurements using interplanetary Lyman α emission from 1999 to 2002
NAKAGAWA Hiromu, FUKUNISHI Hiroshi, WATANABE Shigeto, TAKAHASHI Yukihiro, TAGUCHI Makoto, LALLEMENT Rosine, EPS, 61, 3, 373, 382, 01 Mar. 2009
Terra Scientific Pub. Co., English

GLIMSミッションに期待される科学~雷放電~
森本健志, 牛尾知雄, 佐藤光輝, 高橋幸弘, INAN Umran, 芳原容英, 菊池雅行, 鈴木睦, 山崎敦, 阿部琢美, 吉田和哉, 坂本祐二, 奥山圭一, 石田良平, 河崎善一郎, 大気圏シンポジウム・講演集(Web), 23rd, 2009

GLIMSミッションに期待される科学:地球ガンマ線現象
高橋幸弘, 嘉瀬浩美, 牛尾知雄, 森本健志, 佐藤光輝, INAN Umran, 芳原容英, 菊池雅行, 鈴木睦, 山崎敦, 阿部琢美, 吉田和哉, 坂本祐二, 奥山圭一, 石田良平, 河崎善一郎, 大気圏シンポジウム・講演集(Web), 23rd, 2009

JEM-GLIMSミッションの概要
牛尾知雄, 鈴木睦, 佐藤光輝, 森本健志, 高橋幸弘, 芳原容英, 菊池雅行, INAN Umran, 山崎敦, 阿部琢美, 河崎善一郎, 大気圏シンポジウム・講演集(Web), 23rd, 2009

GLIMSミッションに期待される科学:高高度発光現象
佐藤光輝, 牛尾知雄, 森本健志, 高橋幸弘, INAN Umran, 芳原容英, 菊池雅行, 石田良平, 吉田和哉, 坂本祐二, 奥山圭一, 河崎善一郎, 鈴木睦, 山崎敦, 阿部琢美, 大気圏シンポジウム・講演集(Web), 23rd, 2009

火星気象と水循環
今村剛, 佐藤毅彦, 上野宗孝, 鈴木睦, 黒田剛史, 笠井康子, 佐川英夫, 高橋幸弘, 高橋芳幸, はしもと じょーじ, 大気圏シンポジウム・講演集(Web), 23rd, 2009

P109 LLSにより観測された首都圏周辺における落雷頻度分布
鶴島 大樹, 境田 清隆, 高橋 幸弘, 本間 規泰, 大会講演予講集, 96, 341, 341, 2009
日本気象学会, Japanese

Estimating lightning current moment waveforms from satellite optical measurements
Adachi, T, S. A. Cummer, J. Li, Y. Takahashi, R.-R. Hsu, H.-T. Su, A. B. Chen, S. B. Mende, H. U. Frey, Geophys. Res. Lett., 36, L18808, 18, L18808, 2009

Monitoring of Lightning Activity in Southeast Asia: Scientific Objectives and Strategies
Adachi Toru, Takahashi Yukihiro, Ohya Hiroyo, Tsuchiya Fuminori, Yamashita Kozo, Yamamoto Mamoru, Hashiguchi Hiroyuki, Kyoto Working Papers on Area Studies: G-COE Series, 11, 1, 20, Dec. 2008
In this report, a newly-developed lightning observation network system is outlined. The network consists of an optical observation site (Padang in Indonesia) and three electromagnetic observation sites (Pontianak in Indonesia, Tainan in Taiwan, and Saraburi in Thailand). At Padang site, a small low-light CCD camera was installed to observe the optical emission of lightning flash. On the other hand, a monopole, a dipole, and a set of orthogonal loop antennas were installed at each site to detect electromagnetic waves in the frequency range of 0.1-40 kHz. The obtained data are analyzed to monitor lightning activity in Southeast Asia in various spatiotemporal scales and clarify severe weather phenomena which cause significant damages on the human activity., Center for Southeast Asian Studies, Kyoto University, English

Global distribution of intense lightning discharges and their seasonal variations
M. Sato, Y. Takahashi, A. Yoshida, T. Adachi, Journal of Physics D: Applied Physics, 41, 01 Dec. 2008
In order to study the temporal and regional variation of lightning occurrences and their relation to sprite activity and climate variability, we have analysed the 1-100 Hz ELF magnetic field waveform data obtained at the Syowa station in Antarctica, Onagawa in Japan and Esrange in Sweden for a one year period from September 2003 to August 2004. We have selected totally 1.7 × 105 events of transient Schumann resonances from the ELF magnetic field data whose amplitude exceeds 40 pT at all stations. Then, the lightning locations are estimated by a triangulation method with an estimation error of 0.5 Mm. It is found that in the summer season (from June to August) the lightning occurrence rates are higher in the northern hemisphere than in the southern hemisphere with large enhancements in North America, South-East Asia and the northern part of Africa. On the other hand, in the winter season (from December to February) these rates are higher in the southern hemisphere with large enhancements in South America, Australia and the southern part of Africa. These features are consistent with the results of global lightning measurements from space conducted by the Optical Transient Detector and the Tropical Rainfall Measuring Mission satellite. Then, we have also calculated the charge moment value (Q · dl) of lightning discharges using ELF magnetic field waveform data and have estimated the distribution function of charge moments for positive cloud-to-ground (+CG) discharges and for negative cloud-to-ground (-CG) discharges. It is found that the shape of the distribution function for both +CG and -CG discharges is almost the same for all seasons and that the distribution function of -CG discharges has a steeper slope at high Q · dl than that of +CG discharges. © 2008 IOP Publishing Ltd.

P229 国際共同木星探査計画(ポスターセッション2)
佐々木 晶, 藤本 正樹, 木村 淳, 高島 健, 笠羽 康正, 山路 敦, 長沼 毅, 桜庭 中, 高橋 幸弘, 栗田 敬, 生駒 大洋, 日本惑星科学会秋期講演会予稿集, 2008, 148, 148, 01 Nov. 2008
日本惑星科学会, Japanese

Development of Scientific Microsatellite SPRITE-SAT for the Observation of Transient Luminous Events in Upper Atmosphere and Terrestrial Gamma-ray Flashes
UJIIE Eriko, YOSHIDA Kazuya, TAKAHASHI Yukihiro, SAKAMOTO Yuji, SAKANOI Takeshi, MASUMOTO Yoshinari, KASABA Yasumasa, KONDO Satoshi, IEICE technical report, 108, 267, 1, 6, 24 Oct. 2008
Tohoku University is now developing the 50-kg microsatellite named SPRITE-SAT, and this is launched by Japanese H-IIA rocket as a piggy-back satellite in the beginning of 2009. The SPRITE-SAT observes one of transient luminous events (TLEs) in the middle and upper atmosphere, called "sprites", and terrestrial gamma-ray flashes (TGFs). The mission of SPRITE-SAT is to solve the generation mechanism of these events. The satellite has a new-model deployable mast, and the bottom panel loading almost mission instruments is pointing to the earth by the gravity gradient torque. In this paper, missions and the satellite system are explained., The Institute of Electronics, Information and Communication Engineers, Japanese

23aSH-9 Development of Terrestrial Gammma-ray Counter onboard a small sattelite
Ueda T., Enoto T., Nakazawa K., Mitani T., Takashima K., Sakanoi K., Uziie E., Kasaba Y., Yoshida K., Takahashi H., Mori K., Makishima K., Meeting abstracts of the Physical Society of Japan, 63, 2, 94, 94, 25 Aug. 2008
The Physical Society of Japan (JPS), Japanese

Future Planetary Atmosphere Missions of Japan
IMAMURA Takeshi, SATOH Takehiko, UENO Munetaka, TERADA Naoki, Planetary people, 17, 1, 54, 57, 25 Mar. 2008
惑星大気探査の将来構想を紹介する.今後10年は地球型惑星である金星と火星を対象として研究を深めつつ経験を蓄積し,将来は木星をも対象とする., The Japanese Society for Planetary Sciences, Japanese

P334 One-month variations in OLR and lightning activity related to solar parameter :
Takahashi Yukihiro, Miyahara Hiroko, Sato Mitsuteru, 大会講演予講集, 94, 479, 479, 2008
日本気象学会, English

VLF帯電波観測網による東南アジア域の雷・電離圏活動のモニタリング
足立透, 大矢浩代, 土屋史紀, 高橋幸弘, 大気圏シンポジウム, 22nd(CD-ROM), 2008

東南アジアVLF観測網による下部電離圏トウィーク反射高度観測計画
大矢浩代, 足立透, 土屋史紀, 高橋幸弘, 大気圏シンポジウム, 22nd(CD-ROM), 2008

地上光学・電磁波観測器とＭＵレーダーを用いた雷活動と電離圏擾乱現象の同時観測　　　　　　　　　　　　　　　
足立透, 山本衛, 大塚雄一, 高橋幸弘, 佐藤光輝, 京都大学生存圏研究所ＭＵ共同利用成果報告書, 2008

JEM-EUSO: Extreme Universe Space Observatory on JEM/ISS
Y. Takizawa, T. Ebisuzaki, Y. Kawasaki, M. Sato, M. E. Bertaina, H. Ohmori, Y. Takahashi, F. Kajino, M. Nagano, N. Sakaki, N. Inoue, H. Ikeda, Y. Arai, Y. Takahashi, T. Murakami, James H. Adams, Nuclear Physics B - Proceedings Supplements, 166, 72, 76, 01 Apr. 2007
EUSO is a super-wide field UV telescope to detect Ultra-High Energy Cosmic-Rays (UHECRs) with energy above 10 20 eV. It is attached to the International Space Station (ISS) and observes fluorescence photons emitted by giant air showers produced by UHECR. The three dimensional development of the shower is reconstructed from a series of images of the shower. Phase-A study of EUSO under the European Space Agency (ESA) has successfully finished in July 2004. The phase-B study, however, has been postponed for a long time because of financial problems in ESA and Italy. Then, Japanese and U.S. teams re-defined EUSO as a mission attached to the Japanese Experiment Module/Exposure Facility of ISS. They renamed it as JEM-EUSO and started the preparation targeting the launch in 2012 in the framework of second phase of JEM/EF utilization. The outline of the mission is presented. © 2007 Elsevier B.V. All rights reserved.

Exploration of Venus’ atmosphere and the future of planetary meteorology
今村剛, 中村正人, 上野宗孝, 佐藤毅彦, 渡部重人, 田口真, 高橋幸弘, 鈴木睦, 岩上直幹, 石井信明, 阿部琢美, 山崎敦, 福原哲哉, 上水一典, 坂野井健, 山田学, 橋本成司, 宇宙科学技術連合講演会講演集(CD-ROM), 51st, 2007

惑星宇宙望遠鏡TOPS:計画の概要ならびにサイエンス検討の現状
高橋幸弘, 坂野井健, 上野宗孝, 笠羽康正, 吉田和哉, 田口真, 山崎敦, 岩上直幹, 今村剛, 鈴木睦, 阿部琢美, 寺田直樹, 寺田直樹, 土屋史紀, 堀之内武, 中島健介, 高橋幸弘, 高橋幸弘, 地球電磁気・地球惑星圏学会総会及び講演会予稿集(CD-ROM), 122nd, 2007

Studies on the radiation tolerance of imaging instruments for Venus mission
今村剛, 上野宗孝, 岩上直幹, 佐藤毅彦, 山田学, 高橋幸弘, 吉田純, 上田真也, 北村尚, NIRS-M (National Inst. of Radiological Sciences), 203, 2007

C216 ISUAL及びELFネットワーク観測に基づく落雷及びスプライト発生率の地域季節変動(降水システムII)
吉田 暁洋, 高橋 幸弘, 佐藤 光輝, 足立 透, 近藤 哲志, Hsu Rue-Ron, Su Han-Tzong, Chen Alfred Bing-Chih, Frey H. U., Mende S. B., Lee Lou-Chuang, 大会講演予講集, 92, 221, 221, 2007
日本気象学会, Japanese

惑星宇宙望遠鏡TOPS:観測計画ならびに搭載機器開発の現状
坂野井健, 高橋幸弘, 上野宗孝, 笠羽康正, 吉田和哉, 山崎敦, 今村剛, 阿部琢美, 田口真, 澤井秀次郎, 高橋幸弘, 地球電磁気・地球惑星圏学会総会及び講演会予稿集(CD-ROM), 122nd, 2007

A306 金星気象衛星による金星雷・大気光観測(スペシャルセッション「惑星大気の科学」I)
吉田 純, 高橋 幸弘, 上田 真也, 堤 雅基, 牛尾 知雄, 大会講演予講集, 90, 70, 70, 2006
日本気象学会, Japanese

A307 地上望遠鏡から探る金星昼側雲構造(スペシャルセッション「惑星大気の科学」I)
吉田 純, 高橋 幸弘, 田村 大輔, 大会講演予講集, 90, 71, 71, 2006
日本気象学会, Japanese

A352 可視近赤外領域における木星昼面多波長撮像観測(スペシャルセッション「惑星大気の科学」II)
高橋 幸弘, 松浦 浩美, 大会講演予講集, 90, 75, 75, 2006
日本気象学会, Japanese

P138 FORMOSAT-2/ISUALで観測されたスプライトの発光形態とそれを誘起した雷放電の電気的特徴
足立 透, 福西 浩, 高橋 幸弘, 山本 桂, Hsu R. R., Su H. T., Chen A. B., Mende S. B., Frey H. U., Lee L. C., 大会講演予講集, 90, 296, 296, 2006
日本気象学会, Japanese

FORMOSAT-2/ISUALで観測されたスプライトの形態と雷放電の電気的特徴　　　　　　　　　　　　　　　
足立透, 福西浩, 高橋幸弘, 平木康隆, 山本桂, R.-R. Hsu, H.-T. Su, A. B. Chen, S. B. Mende, H, U. Frey, C. Lee, 第２０回大気圏シンポジウム原稿集, 2006

観測システム紹介3: 衛星による超高層発光現象の観測　　　　　　　　　　　　　　　
足立透, 福西浩, 高橋幸弘, R.-R. Hsu, H.-T. Su, A. B. Chen, S. B. Mende, H, U. Frey, C. Lee, MTI ハンドブック（2006年度）, 2006

Electric field transition between the diffuse and streamer regions of sprites estimated from ISUAL/array photometer measurements
Adachi, T, H. Fukunishi, Y. Takahashi, Y. Hiraki, R.-R Hsu, H.-T. Su, A. B. Chen, S. B. Mende, H. U. Frey, L. C. Lee, Geophys. Res. Lett., 33, 17, L17803-L17803-5, 2006

Development of Lightning and Airglow Camera onboard Venus Climate Orbiter
Yoshida Jun, Takahashi Yukihiro, Fukunishi Hiroshi, Tsutsumi Masaki, Ushio Tomoo, JAXA research and development report, 4, 1, 54, Mar. 2005
We are developing a lightning and airglow camera (LAC) onboard the Venus Climate Orbiter (VCO) , the Japanese Venus mission Planet-C. The LAC is a high-speed imaging sensor and measures lightning flashes and airglow emissions on the Venus nightside disk. One of the major targets of LAC is to settle controversy on the existence of the lightning of Venus. Further, the LAC observations provide us information for the charge separation mechanism, physics of sulfuric acid clouds, mesoscale planetary meteorology and impacts on atmospheric chemical processes. The regions of intense airglow emission normally distributed on the morning side of the antisolar point, which reflects that the super-rotation of the upper atmosphere modifies subsolar-to-antisolar circulation cell. So continuous observations of nightglow provide us information on the global circulation in the Venus lower thermosphere. Furthermore, we are planning to measure the 558 nm [OI]emission which was recently discovered by a ground-based telescope, but its origin is mysterious.Both high-sensitivity and high-speed samplings are performances required for the detector of LAC.And it needs to have 8 by 8 matrix. Interference filters are used for selecting a wavelength of 777 nm [OI]for lightning flash measurement and wavelength of 551 nm[O_2 Herzberg II]and 558 nm[OI]for nightglow measurement. Individual lightning flash events are recorded with a 50 kHz pre-trigger sampling. The goal of LAC is to detect lightning events with the optical intensity of 1/100 of typical lightning events on the Earth from 1000 km altitude and to measure 100 Rayleigh airglow with signal to noise ratio (S/N) more than 10. To realize this performance, first, we selected and examined of photo-multiplier tube (PMT) and avalanche photo-diode (APD) as a candidate of the detector of LAC. We performed an absolute calibration of the optical sensitivity and a measurement of thermal characteristics of dark current.These results shows both PMT and APD have an ability to satisfy S/N more than 10 when LAC observes 100 Rayleigh airglow emission using them. But the problem of PMT is low quantum efficiency, while the one of APD is thermal instability of dark current. So we conclude that PMT is suitable to detect airglow emission and APD is useful to observe lightning flash. Second, we designed and developed a high-contrast optics of which reduces stray-light by an order of 10^<-11>.When the LAC observes the Venus nightside disk, the light from the sun and Venus dayside disk are serious contaminations. To reduce them, we install LAC on the surface of the satellite and set four vanes on the objective side of the camera. However, the light scattered by the surface of the satellite and the objects put on the surface, such as antenna, may seriously reduce the signal to noise ratio. We are evaluated the intensity of these scattered light using detailed models to solve this problem. The results indicate that the amount of scattered light can be sufficiently reduced by a baffle under the condition that the projecting objects put at the backward of the baffle aperture. Third, We designed of data acquisition for high-speed pre-trigger sampling. We devised a very simple trigger logic using oblivion coefficient and tested for terrestrial lightning flashes data obtained with a photometer on the ground. It is confirmed that this logic is quite useful to distinguish between the lightning signal and other noises., Japan Aerospace Exploration Agency, Japanese

惑星宇宙望遠鏡のサイエンステーマと光学系設計
坂野井 健, 高橋 幸弘, 吉田 和哉, 宇宙科学シンポジウム, 5, 392, 395, 06 Jan. 2005
宇宙科学研究所, Japanese

惑星宇宙望遠鏡の科学目標と技術検討
高橋 幸弘, 坂野井 健, 吉田 和哉, 宇宙科学シンポジウム, 5, 368, 375, 06 Jan. 2005
宇宙科学研究所, Japanese

C410 北陸地方における冬季スプライト発生時の気象場の特徴(降水システムII)
小笠原 麻喜, 新野 宏, 高橋 幸弘, 大会講演予講集, 87, 193, 193, 2005
日本気象学会, Japanese

ROCSAT-2/ISUAL Array Photometer によるスプライト観測：電場の推定　　　　　　　　　　　　　　　
足立透, 福西浩, 高橋幸弘, 平木康隆, R.-R. Hsu, H.-T. Su, A. B. Chen, S. B. Mende, H, U. Frey, C. Lee, 第１９回大気圏シンポジウム原稿集, 2005

Characteristics of thunderstorm systems producing winter sprites in Japan
Adachi, T, H. Fukunishi, Y. Takahashi, M. Sato, A. Ohkubo, K. Yamamoto, J. Geophys.Res, 110, D11, D11203, doi: 10.1029/2004JD005012, 2005

28pSE-11 EUSO ミッション (29) MAPMT 開発状況(超高エネルギー宇宙線, 宇宙線)
永野 元彦, 宮崎 芳郎, 高橋 幸弘, 村上 敏夫, 米徳 大輔, 木舟 正, 石川 正, 金子 敏明, 栗原 良将, 清水 韶光, 藤本 順平, 竹田 成宏, 林田 直明, 間瀬 圭一, 井上 直也, 和田 吉満, 上野 嘉之, 上原 嘉宏, 戎崎 俊一, 大谷 知行, 大森 整, 川井 和彦, 川崎 賀也, 榊 直人, 佐藤 光輝, 清水 裕彦, 鈴木 亨, 滝澤 慶之, Bertaina M E, 森田 晋也, 林 偉民, 北本 俊二, 近 匡, 本田 建, 梶野 敏貴, 水本 好彦, 内堀 幸夫, 吉田 滋, 門多 顕司, 柴田 徹, 吉田 篤正, 高橋 義幸, 梶野 文義, 佐藤 文隆, 坂田 通徳, 山本 嘉昭, 田島 俊樹, 千川 道幸, 政池 明, 川上 三郎, 吉井 尚, 手嶋 政廣, 日本物理学会講演概要集, 59, 2, 81, 81, 25 Aug. 2004
一般社団法人日本物理学会, English

小型衛星搭載惑星宇宙望遠鏡開発計画
高橋 幸弘, 坂野井 健, 吉田 和哉, 宇宙科学シンポジウム, 4, 445, 448, 08 Jan. 2004
宇宙科学研究所, Japanese

A117 EQUARS衛星に搭載される大気光・雷カメラALISによるスプライト観測(降水システムI)
高橋 幸弘, 足立 透, 近田 昌吾, 高橋 久夫, 今村 剛, 大会講演予講集, 86, 42, 42, 2004
日本気象学会, Japanese

P132 ROCSAT-2/ISUALによる雷放電発光現象のグローバル観測 : 初期結果
福西 浩, 高橋 幸弘, 足立 透, Hsu R. -R., Su H. -T., Chen A. -B., Mende S. B., Frey H. U., Lee L. -C., 大会講演予講集, 86, 423, 423, 2004
日本気象学会, Japanese

P131 ROCSAT-2/ISUALによる雷放電発光現象のグローバル観測 : アレイフォトメータによる観測
足立 透, 福西 浩, 高橋 幸弘, Hsu R. R., Su H. T., Chen A. B., Mende S. B., Frey H. U., Lee L. C., 大会講演予講集, 86, 422, 422, 2004
日本気象学会, Japanese

P144 日本の冬季スプライトを発生させる雷雲の特徴
足立 透, 福西 浩, 高橋 幸弘, 佐藤 光輝, 大久保 敦史, 大会講演予講集, 85, 266, 266, 2004
日本気象学会, Japanese

日本に発生する冬季スプライトと雷雲に関する研究　　　　　　　　　　　　　　　
足立透, 福西浩, 高橋幸弘, 佐藤光輝, 第１８回大気圏シンポジウム原稿集, 2004

金星特集号に寄せて
高橋 幸弘, 今村 剛, 遊・星・人 : 日本惑星科学会誌, 12, 4, 230, 230, 25 Dec. 2003
日本惑星科学会, Japanese

Lightning on Venvs
YOSHIDA Jun, TAKAHASHI Yukihiro, Planetary people, 12, 4, 261, 267, 25 Dec. 2003
The Japanese Society for Planetary Sciences, Japanese

Electrical discharges between thunderclouds and the ionosphere
Takahashi Y., Sato M., Hiraki Y., Tohoku Univ sprites research group, Meeting abstracts of the Physical Society of Japan, 58, 2, 134, 134, 15 Aug. 2003
The Physical Society of Japan (JPS), Japanese

惑星専用宇宙望遠鏡の構想
高橋 幸弘, 坂野井 健, 吉田 和哉, 宇宙科学シンポジウム, 3, 453, 456, 09 Jan. 2003
宇宙科学研究所, Japanese

S-310-32号機ロケット放出TMAで誘起された発光現象の機構
福西 浩, 荒川 真木子, 高橋 幸弘, 宇宙科学シンポジウム, 3, 551, 554, 09 Jan. 2003
宇宙科学研究所, Japanese

小型衛星によるスプライト及び雷の光学観測
足立 透, 高橋 幸弘, 大久保 敦史, 宇宙科学シンポジウム, 3, 415, 418, 09 Jan. 2003
宇宙科学研究所, Japanese

P308 静止衛星からの次世代大気科学観測について
鈴木 睦, 奥村 真一郎, 吉田 重臣, 小川 利紘, 北 和之, 今村 剛, 中村 正人, 高橋 幸弘, 牛尾 知雄, 大会講演予講集, 84, 387, 387, 2003
日本気象学会, Japanese

P323 日本における冬季スプライトと雷・雷雲の関係
足立 透, 福西 浩, 高橋 幸弘, 佐藤 光輝, 大久保 敦史, 大会講演予講集, 84, 402, 402, 2003
日本気象学会, Japanese

A360 静止衛星からの次世代大気科学観測 : 衛星構想(衛星からの大気観測 : 日本の貢献と将来展望II)
鈴木 睦, 奥村 真一郎, 吉田 重臣, 小川 利紘, 北 和之, 今村 剛, 中村 正人, 高橋 幸弘, 牛尾 知雄, 大会講演予講集, 84, 83, 83, 2003
日本気象学会, Japanese

A363 静止衛星からの次世代大気科学観測 : (3)雷観測(衛星からの大気観測 : 日本の貢献と将来展望II)
高橋 幸弘, 牛尾 知雄, 堤 雅樹, 鈴木 睦, 奥村 真一郎, 吉田 重臣, 大会講演予講集, 84, 86, 86, 2003
日本気象学会, Japanese

P347 ROCSAT-2衛星搭載の上空放電発光観測用フォトメータの開発
高橋 幸弘, 足立 透, 福西 浩, 大会講演予講集, 83, 418, 418, 2003
日本気象学会, Japanese

P346 冬季日本に発生するスプライトと雷雲の特徴
足立 透, 福西 浩, 高橋 幸弘, 大会講演予講集, 83, 417, 417, 2003
日本気象学会, Japanese

P348 ELF帯磁場波形データから推定されるスプライトの全球発生頻度分布
佐藤 光輝, 福西 浩, 高橋 幸弘, 大会講演予講集, 83, 419, 419, 2003
日本気象学会, Japanese

Proposal of the observation of meteor-related phenomena using small satellite.
山本真行, 矢野創, 阿部新助, 吉田和哉, 高橋幸弘, 海老塚昇, 清水裕彦, 宇宙科学シンポジウム 平成14年度 第3回, 2003

Global survey of upper atmospheric transient luminous events on the ROCSAT-2 satellite
Chern, J. L, R. R. Hsu, H. T. Su, S. B. Mende, H. Fukunishi, Y. Takahashi, L. C. Lee, J. Atmos. Solar. Terr. Phys, 65, 5, 647, 659, 2003

火星探査衛星「のぞみ」搭載紫外撮像分光計UVS星間水素観測を用いた性能評価 (第2回宇宙科学シンポジウム)
中川 広務, 福西 浩, 高橋 幸弘, 宇宙科学シンポジウム, 2, 491, 494, 19 Nov. 2001
宇宙航空研究開発機構宇宙科学研究本部, Japanese

スプライト発光現象観測の将来 (第2回宇宙科学シンポジウム)
福西 浩, 高橋 幸弘, Mende S. B., 宇宙科学シンポジウム, 2, 323, 330, 19 Nov. 2001
宇宙航空研究開発機構宇宙科学研究本部, Japanese

積乱雲からの上方放電(スプライト)
高橋 幸弘, 大会講演予講集, 79, 171, 171, 08 May 2001
Japanese

のぞみ探査衛星搭載UVSにより観測された星間水素の全天マップと時間・空間変動
福西 浩, 船橋 豪, 高橋 幸弘, 宇宙科学シンポジウム, 1, 253, 256, 11 Jan. 2001
宇宙科学研究所, Japanese

超高層雷放電発光現象の衛星観測計画
福西 浩, 高橋 幸弘, Mende S.B., 宇宙科学シンポジウム, 1, 165, 172, 11 Jan. 2001
宇宙科学研究所, Japanese

S105 Venus orbiter mission
今村 剛, 高橋 幸弘, はしもと じょーじ, Abstracts Fall Meeting of the Japanese Society for Planetary Sciences, 2000, 83, 83, 31 Oct. 2000
The Japanese Society for Planetary Sciences, Japanese

S107 Space Telescpoe for Observation of Planets
高橋 幸弘, 倉本 圭, 今村 剛, Abstracts Fall Meeting of the Japanese Society for Planetary Sciences, 2000, 85, 85, 31 Oct. 2000
日本惑星科学会, Japanese

A opinion poll about future planetary exploration given to students and young scientists
TAKAHASHI Yukihiro, KURAMOTO Kiyoshi, Planetary People, 9, 1, 33, 46, 25 Mar. 2000
The Japanese Society for Planetary Sciences, Japanese

金星探査/気象衛星の搭載機器と観測戦略
竹内 覚, 今村 剛, 小山 孝一郎, 笠羽 康正, 高橋 幸弘, 松田 佳久, 金星探査計画ワーキンググループ, 大会講演予講集, 76, 401, 401, 24 Nov. 1999
Japanese

In vitro fertilization and cortical granule distribution of bovine oocytes having heterogeneous ooplasm with dark clusters
M Nagano, Y Takahashi, S Katagiri, JOURNAL OF VETERINARY MEDICAL SCIENCE, 61, 5, 531, 535, May 1999
In vitro maturation, fertilization and subsequent development of oocytes with homogeneous (category 1), or heterogeneous ooplasm (category 2) were investigated. No significant differences were observed in the nuclear maturation and total fertilization rates between the two categories. However, category 2 oocytes showed a higher normal fertilization rate due to their lower incidence of polyspermy as compared to category 1 oocytes. Electron microscopic study revealed that all category 2 oocytes had cortical granules lined up next to the plasma membrane, and that some category 1 oocytes still had small clusters of cortical granules after maturation. Although the proportion of cleaved zygotes was higher in category 2, the percentages of cleaved zygotes that developed to the blastocyst stage did not differ between the two categories. These results demonstrate that oocytes with heterogeneous ooplasm have a higher capacity for normal fertilization due to the reduction in polyspermy. This can be attributed to the normal distribution of cortical granules in category 2 oocytes after maturation., JAPAN SOC VET SCI, English

Height Determination of the OH Airglow Layer Based on the Imaging Observation during the SEEK Campaign
TOKI Tsuyoshi, TAKAHASHI Yukihiro, YAMADA Yoshinori, FUKUNISHI Hiroshi, NAKAMURA Takuji, TAYLOR Michal J., 宇宙科学研究所報告. 特集, 38, 83, 91, Mar. 1998
In order to investigate the relationships between gravity wave structures of airglow and the quasi-periodic field-aligned irregularities observed by radars, we carried out the ground-based imaging obsevations at three sites in Kagoshima and at Shigaraki during The SEEK (Sporadic-E Experiment over Kyushu) campaign. Simultaneous observations of OH airglow were conducted using two all-sky CCD imagers installed at Uchinoura and Yamagawa, Kagoshima, Japan, respectively. All-sky images of OH airglow displayed a distinct wave structure with a horizontal wavelength of ∿23km at both sites on August 19,1996. The neutral winds in the altitude range of 60-100 km were observed simultaneously by the MF radar at Yamagawa. Applying a triangulation method to these data, we have estimated the height of this small-scale wave structure. The estimated altitude was 89±3km, which was just below the neutral wind enhancements (reaching ∿120m/s) observed in the altitude range of 91-94km by the MF radar., Japan Aerospace Exploration Agency, Japanese

9.終わりに(中間圏界面領域の大気構造と力学過程に関する国際シンポジウム(DYSMERシンポジウム)の報告)
津田 敏隆, 中村 卓司, 三好 勉信, 川原 琢也, 堤 雅基, 村山 泰啓, 高橋 幸弘, 坂野井 健, 天気, 45, 11, 848, 849, 1998
日本気象学会, Japanese

7.セッションAGS:大気光グローバル構造(中間圏界面領域の大気構造と力学過程に関する国際シンポジウム(DYSMERシンポジウム)の報告)
高橋 幸弘, 坂野井 健, 天気, 45, 11, 847, 848, 1998
Japanese

Optical characteristics of elves observed by FORMOSAT-2/ISUAL and properties of parent lightning discharges　　　　　　　　　　　　　　　
Y. Takahashi, T. Adachi, A. Ohkubo, K. Yamamoto, S. Chikada, H. Fukunishi, H. _T. Su, A. B. Chen, R. _R. Hsu, S. B. Mende, H. U. Frey, L. C. Lee
International Association of Meteorology and Atmospheric Sciences (IAMAS) 2005 meeting, English
Beijing, China, [Invited]

Characteristics of TLEs observed by ISUAL/AP onboard FORMOSAT-2　　　　　　　　　　　　　　　
Y. Takahashi, T. Adachi, H. Fukunishi, S. Chikada, A. Yoshida, K. Yamamoto, R-R. Hsu, H-T. Su, A. Chen, S. B. Mende, H. U. Frey, L-C. Lee
American Geophysical Union (AGU) 2006 Fall meeting, English
San Francisco, US, [Invited]

SPRITE-SAT mission for sprites and TGFs studies　　　　　　　　　　　　　　　
Y. Takahashi, T. Sakanoi, M. Sato, S. Kondo, K. Yoshida, Y. Sakamoto, E. Ujiie, T. Takashima, U. Inan, D. Smith
European Geoscience Union general assembly, English
Vienna, Austria, [Invited]

Lifetime and structures of TLEs captured by high-speed camera on board aircraft　　　　　　　　　　　　　　　
Y. Takahashi, Y. Sanmiya, M. Sato, T. Kudo, NHK Cosmic Shore Project, Y. Yair, S. A. Cummer
American Geophysical Union 2012 Fall Meeting, English
San Francisco, US, [Invited]

Role and Scope of Asian Micro-satellite Consortium　　　　　　　　　　　　　　　
Yukihiro Takahashi
34th Asia Conference on Remote Sensing “Applications of remote sensing technology on tropical peatlands”, English
Bali, Indonesia, [Invited]

A Scope of Asian Micro-satellite Consortium　　　　　　　　　　　　　　　
Yukihiro Takahashi
IEEE Workshop on Geoscience and Remote Sensing 2013, English
Melaka, Malaysia, [Invited]

High frequency / precision disaster monitoring with micro-satellite constellation　　　　　　　　　　　　　　　
Yukihiro Takahashi
UN World Conference on Disaster Risk Reduction 2015, English
Sendai, Japan, [Invited]

Collaborative Promotion of Micro-satellite Utilization by International Consortium　　　　　　　　　　　　　　　
Yukihiro Takahashi
APRSAF-17, English
Manila, Philippines, [Invited]

Next-generation Earth Monitoring System with Micro-satellites and Ground-based Networks　　　　　　　　　　　　　　　
Yukihiro Takahashi
17th Conference of the Science Council of Asia, English
Manila, Philippines, [Invited]

Identification of UV absorbers and derivation of solar heating rate as driving sources of atmospheric circulation of Venus
Grants-in-Aid for Scientific Research
05 Apr. 2021 - 31 Mar. 2026
田口 真, 高橋 幸弘, 佐藤 光輝, 中野 壽彦, 莊司 泰弘, 今井 正尭
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Rikkyo University, 21H04522

Precise monitoring and prediction of typhoon based on high resolution 3D cloud imaging and lightning observation
Grants-in-Aid for Scientific Research
09 Jul. 2021 - 31 Mar. 2025
高橋 幸弘, 佐藤 光輝, 久保田 尚之
本研究では、超小型衛星と雷放電測網を組み合わせた、これまでに例のない超高精度の台風監視と予測を行うための観測システムを低コストで実現する手段に見通しをつけることを目的としている。2021年度は、RISESAT衛星およびDIWATA-2衛星の2機の50kg級超小型衛星を運用して、延べ12回のオンディマンド運用のキャンペーン観測を実施し、そのうち台風本体の観測は5回行った。また、過去の航空機および超小型衛星による3D観測の詳細な解析を進め、それらをひまわり8号の熱赤外線観測から推定した雲頂高度分布と比較し、一致しないことを確認した。これにより、大気のスケールハイトの水平分布を推定し、鉛直対流分布の手がかりを得るという手法に見通しが立った。雷放電観測では、既設の地上観測システムのデータに基づき、台風の発生時および発達期の活動を調査し、フィリピン近海で発生する場合は、著しい雷放電活動が先行することを発見した。
Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Research (Pioneering), Hokkaido University, 21K18177

Study of relationship between global electric circuit and clouds
Grants-in-Aid for Scientific Research
01 Apr. 2021 - 31 Mar. 2024
大矢 浩代, 鷹野 敏明, 高橋 幸弘
本研究課題は、本研究グループが開発した世界最高クラスの空間分解能（300 m 高度で1 m、15 km 高度で 47 m）を有するWバンド雲レーダFALCON-Ⅰと、大気電場観測ネットワークを組み回せた観測システムを構築することで、グローバルサーキットの気象現象への影響を評価するための基礎的な知見を得ることを目的としている。その目的遂行のため、2021年度は、流通経済大学（茨城県龍ヶ崎市）および東北大学（宮城県仙台市）の2か所に、大気電場計を新規設置した。千葉大学（千葉県千葉市）での大気電場観測は、2016年6月から行っており、これで3か所への設置を完了した。また、2台の全天カメラを用いた雲底高度推定法と、雲画像からRGB値を使用した雲量推定法を提案し、それらの自動推定プログラムを開発した。これにより、統計的に雲パラメータと大気電場との比較が行えるようになった。
さらに、グローバルサーキットと気象現象との関連性を明らかにするため、Wバンド雲レーダFALCON-Iを用いて、千葉における地上大気電場と、雨、雷雨および雪の気象現象との比較を行った。その結果、降雨については、雲による長周期の極性の大気電場変動および雨粒落下による数十秒の速い変動が見られた。雨粒(負電荷) 落下により、大気電場は負（電場は上向き）となった。雷雨については、雲による大気電場の極性の変化および雷による1-2分程度のパルス状の変動が見られた。雷雲のアンビル（雲のトップ）は上昇流があり、その対流セルが大気電場に影響を与えている可能性がある。降雪については、数十分周期の大気電場振動があり、雪雲内部の構造が振動の原因となっていると思われる。
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Chiba University, 21K03679

3-D structure of thundercloud estimated by imaging on the ground and from micro-satellite
Grants-in-Aid for Scientific Research
28 Jun. 2019 - 31 Mar. 2021
TAKAHASHI YUKIHIRO
The purpose was to establish a method for providing a three-dimensional structure of clouds with high resolution by using 3D model software for cloud imaging from satellites and multiple observation sits on the ground. During the research period, we carried out observation campaigns both from the satellite and the ground, and succeeded in acquiring simultaneous images. However, due to the COVID-19, the opportunities for both satellite operation and ground observation were significantly limited, so it was not possible to capture cumulonimbus clouds suitable for analysis. On the other hand, we performed 3D analysis of the data obtained from the satellite, aircraft, and ground observations acquired in the research period and past, and succeeded in estimating the 3D cloud structure inside the eye of the typhoon and cumulonimbus clouds with the highest resolution in the world. We have also completed the development of a fully automatic ground photography system.
Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Research (Exploratory), Hokkaido University, 19K22021

A study on temporal variation of the Venus atmosphere using a circumpolar stratospheric telescope FUJIN
Grants-in-Aid for Scientific Research
01 Apr. 2015 - 31 Mar. 2018
TAGUCHI Makoto
The circumpolar stratospheric telescope FUJIN-2 has been developed for observations of planetary atmospheres and plasmas. The dynamics, chemistry and identification of an UV abosorber of the Vinus atmosphere are selected as the first scientific target. Development of the hardware of FUJIN-2 has been promoted based on the experimental data obtained by FUJIN-1. Development of the optics, electrical and attitude control systems has been completed. A balloon experiment at ESRANGE in Kiruna, Sweden has been proposed. As an important scientific result about the Venus atmosphere large stationary thermal structures have been discovered by the Longwave Infrared Camera onboard the Venus orbiter Akatsuki. From detaied analysis of the observed data it is suggested that atmospheric gravity waves generated in the lower atmosphere by the solar radiation energy propagate to the cloud-top altitudes forming the structures.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Rikkyo University, 15H03734

Urban thunderstorms over the Indonesian maritime continent: Their climatology and mesoscale dynamics observed with multiple radars
Grants-in-Aid for Scientific Research
01 Apr. 2013 - 31 Mar. 2016
MORI Shuichi, HATTORI Miki, YAMANAKA Manabu, HASHIGUCHI Hiroyuki, TAKAHASHI Yukihiro, HAMADA Jun-Ichi
We studied both climatology and mesoscale behavior of urban thunderstorm around Jakarta, Indonesia, where is suffered serious social damages from severe lightning. We found frequency of thunderstorm varies much with phases of eastward moving convective intraseasonal oscillation (MJO) and shows it maximum just before when the MJO active region comes over Jakarta based on long-term operational surface observation. Seasonal march of thunderstorm has much spatial variability: It shows two maxima (April and November) just before rainy seasons at most stations around Jakarta, whereas it has a peak on February only at coastal stations nearby the Jawa Sea due to intrusion of cross equatorial northerly monsoon surge (CENS). Radar observations showed that most thunderstorms have remarkable diurnal variation: they were generated in mountainous region of southern Jawa Island in the early afternoon and migrated northward by the late evening which brought lightning over Jakarta city nearby the sea.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Japan Agency for Marine-Earth Science and Technology, 25350515

Study on relationship between strong rainfall and local circulation in the Fukui plain
Grants-in-Aid for Scientific Research
01 Apr. 2013 - 31 Mar. 2016
Nakajo Tomoyuki, Aoyama Takashi, Ujihashi Yasuyuki, Kato Yoshinobu, Hashiguchi Hiroyuki, YAMAMOTO Masayuki, Takahashi Yukihiro, Sakamoto Yuji, Kuwahara Toshinori
We statistically compared wind data at lower troposphere based on wind profiler radars with precipitation distribution data based on C-band weather radar in order to investigate the effects of interaction between terrain and lower wind on precipitation patterns in the Fukui plain. The results show detailed precipitation patterns in the Fukui plain are classified by wind at altitude lower than 1 km. In particular, localized strong rainfall often occurs in the northern area of Fukui plain in the condition that wind at altitude lower than 1 km is westerly. These results indicate the measurement of lower wind at altitude lower than 1 km is important on local weather forecasting.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Fukui University of Technology, 25350509

Observational investigation for effects of the lightning discharges in South-east Asia on the D/E-region ionosphere
Grants-in-Aid for Scientific Research
01 Apr. 2013 - 31 Mar. 2016
Ohya Hiroyo, TAKAHASHI Yukihiro, TSUCHIYA Fuminori, YAMASHITA Kozo
During 2013-2015 physical years, we could install new VLF observation system in Philippines and Vietnam to reveal the effects of lightning discharges on the lower ionosphere. All the five observation stations of Asia VLF Observation Network (AVON) were completed. By analyzing the AVON data, the following results were obtained.
(1) The phase change strongly depends in both strength of EMP and distance of causative lightning from the 1-hop point, if the strength of the EMP exceeds the breakdown electric field at 90 km altitude. (2) Outside of these distances, the phase decreases (which correspond to the ionization decrease) was found. Intensity of EMP degreases as distance from a causative lightning. When the electric filed strength becomes lower than the breakdown threshold, electron attachment rate dominates ionization rate, causing decrease in ionization. This suggests that EMP does not affect ionization state in the lower ionosphere just above lightning.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Chiba University, 25302005

Prediction of torrential rainfall using lightning observation network in Asia
Grants-in-Aid for Scientific Research
01 Apr. 2012 - 31 Mar. 2016
Takahashi Yukihiro
In order to establish the methodology to make a now cast of thunderstorm, we constructed the ground-based lightning observation networks and investigated the relationship between lightning activity and other meteorological parameters. We completed the construction of the most reliable VLF radio wave network in Southeast Asia and the domestic dense observation network with sensors at every 4 km. We established the methodology of automatic tracking of precipitating and lightning regions, respectively. We found a good correlation between the precipitation area/intensity and lightning frequency. Also we indentified the significant decrease of lightning frequency 10-130 min before down burst. About typhoon activity, we discover the large variation of lightning discharge in charge moment distribution and polarity of the current.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Hokkaido University, 24253002

Identification of the occurrence conditions and mechanisms of transient luminous events from space- and ground-based observations
Grants-in-Aid for Scientific Research
01 Apr. 2012 - 31 Mar. 2016
SATO Mitsuteru, USHIO Tomoo, MORIMOTO Takeshi, HOBARA Yasuhide, TAKAHASHI Yukihiro, SUZUKI Makoto, TSUCHIYA Fuminori, OYA Hiroyo, KAMOGAWA Masashi, NAKADA Hiroyuki, ADACHI Toru
The main objective of this research is to identify the occurrence conditions of sprites. For this purpose, the horizontal distributions of sprites and the electrical properties of the sprite-producing lightning discharges are studied using the data obtained by the JEM-GLIMS measurements at the ISS and using ground-based lightning data. First, we established the analytical method to identify weak sprite emissions from the incomparably intense lightning emissions in the JEM-GLIMS data. Based on the detailed data analyses of the 42 sprite events identified by that method, the spatial distributions of sprites and the horizontal displacement of the sprites from the sprite-producing lightning discharges are quantitatively identified. From the detailed comparison between the sprite distributions and source locations of the VHF pulses excited by the sprite-producing lightning currents, which is the first result in the world, the occurrence conditions of the sprites are clarified.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 24340117

Development of polarization camera for micro-satellite and drone
Grants-in-Aid for Scientific Research
01 Apr. 2013 - 31 Mar. 2015
TAKAHASHI Yukihiro, OKA Kazuhiko
Though polarimetry from satellite or airplane has a great potential in identifying tree species or in measuring size of the cloud particle, this methodology has not been common since the conventional polarization camera is too large, heavy and complicated. In this study, we succeeded in developing a small and light polarization camera with a dimension of 10 x 10 x 20 cm suitable for micro-satellite or small drone, using new technology of polarimetry which doesn’t need moving device. Basic optical performance was confirmed in the laboratory experiment. Also it was found that this polarization camera has a high ability to distinguish a living plant from an imitation. In summary the methodology of new type of polarization camera applicable to the micro-satellite/drone use was established.
Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Exploratory Research, Hokkaido University, 25550005

Study on the Venusian atmosphere by a circumpolar stratospheric telescope
Grants-in-Aid for Scientific Research
01 Apr. 2012 - 31 Mar. 2015
TAGUCHI Makoto, YOSHIDA Kazuya, SAKAMOTO Yuji, TAKAHASHI Yukihiro, WATANABE Makoto, SHOJI Yasuhiro
A balloon-borne telescope system FUJIN lifted up in the Arctic stratosphere has been developed for a long-term continuous observation of planetary atmospheres and plasmas. FUJIN-1 which was a domestic balloon experiment in order to verify techniques of high-precision attitude control and pointing of a target planet was cancelled twice because of a bad weather condition and an accident in the balloon control system. However, the purpose of FUJIN-1 has been accomplished by ground-based prelaunch tests, and development of FUJIN-2 was started aiming at a long-duration flight in the Arctic. In the future a 1-meter class circumpolar stratospheric telescope will be operated as a quasi-permanent platform in the environment without atmospheric turbulent as ground-based and satellite telescopes.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Rikkyo University, 24244076

Long-term changes of precipitation intensity in monsoon Asia
Grants-in-Aid for Scientific Research
18 Nov. 2011 - 31 Mar. 2014
MATSUMOTO Jun, KUBOTA Hisayuki, FUJIBE Fumiaki, HAYASHI Taiichi, YAMAMOTO Haruhiko, ZAIKI Masumi, TERAO Toru, MURATA Fumie, TAKAGASHI Yukihiro, YAMASHITA Kozo, AKASAKA Ikumi, ENDO Nobuhiko, MORI Shuichi, KAMAHORI Hirotaka, TAKAHASHI Hiroshi, YAMANE Yusuke, OTSUKA Michiko, ENDO Hirokazu
Paper or image format daily precipitation data and typhoon tracks in monsoon Asian countries including Japan back into the beginning of the 20th century have been digitized, and long-term changes of precipitation intensity on a daily basis have been analyzed. The precipitation intensity since 1930 has strengthened widely over Japan, in particular, with statistical significance in Northeast Japan. Precipitation intensity since 1950 in the Philippines has increased in summer, whereas drying trend is detected in the west coast region in winter. These trends are different when compared with those prior to 1940. Also precipitation intensity has been affected by both ENSO event and global warming. Difference of precipitation intensity trend between pre- and post-1950 has also recognized in Central Vietnam.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Tokyo Metropolitan University, 23240122

Network observations of raindrop size distribution over Indonesian maritime continent
Grants-in-Aid for Scientific Research
01 Apr. 2011 - 31 Mar. 2014
HASHIGUCHI Hiroyuki, YAMAMOTO Masayuki, MORI Shuichi, TAKAHASHI Yukihiro
It is important to measure not only rain amount but also raindrop size distribution (DSD) to understand a rain mechanism. The network observations of DSD over Indonesian maritime continent is indispensable. Disdrometers were installed at Kototabang (Sumatra), Pontianak, (Kalimantan), Manado (Sulawesi) and Biak (New Guinea), and the continuous observations of DSD were carried out. It clarified about the relation of longitude, a precipitating cloud type, MJO, thunder activity, etc. and the DSD characteristics.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Kyoto University, 23340142

Investigations on TLEs and TGFs using micro-satellite and ground observation network
Grants-in-Aid for Scientific Research
2007 - 2009
TAKAHASHI Yukihiro, YOSHIDA Kazuya, SAKAMOTO Yuji, SAKANOI Takeshi, FUJIWARA Hitoshi, MURATA Isao, MITANI Takefumi, NAKAZAWA Kazuhiro, TAKASHIMA Takeshi, TSUCHIYA Fuminori, OHYA Hiroyo, KAMOGAWA Masashi, SATO Mitrsuteru, ADACHI Toru
In order to investigate TLEs, TGFs, global lightning activities, and their effects on the atmosphere/ionosphere/magnetosphere, university microsatellite, named SPRITE-SAT (RISING) was developed successfully and launched in January 2009. Ground-based lightning observation networks using ELF and VLF radio wave were also developed and operated. Based on the data obtained by the ground-based instruments and previously launched satellites, various kinds of data analysis have been carried out, which contribute to the understanding of basic mechanisms of TLEs/TGFs, global lightning activity and their quantitative effects.
Japan Society for the Promotion of Science, Grant-in-Aid for Specially Promoted Research, 19002002

Comprehensive research on magnetosphere -ionosphere-thermosphere-mesosphere coupling process using the EISCAT radars and other instruments
Grants-in-Aid for Scientific Research
2006 - 2009
FUJII Ryoichi, NOZAWA Satonori, OYAMA Shin-ichiro, OGAWA Yasunobu, EBIHARA Yusuke, MAEDA Sawako, WATANABE Shigeto, FUJIWARA Hitoshi, TAKAHASHI Yukihiro, SAKANOI Takeshi, HIRAHARA Masafumi, ASAMURA Kazushi, HOSOKAWA Keisuke, MOTOBA Tetsuo, KOIZUMI Noriko, KAWAHARA Takuya
EISCAT radars are one of the greatest tools in the world for observing ionospheric phenomena in the auroral, polar cusp and cap regions. EISCAT radar systems provide us with essential physical parameters over the polar ionosphere. Solar-Terrestrial Environment Laboratory (STEL) has been playing a central role in promoting a variety of research projects using the ESR and KST radars of the EISCAT Scientific Association. Both STEL and NIPR, in collaboration with researchers across the nation, have conducted about 50 Special Program (SP) experiments such as Magnetosphere-Ionosphere coupling process using simultaneous observations by REIMEI satellite and EISCAT, DELTA-2 rocket campaign, vertical wind in the lower thermosphere, wind dynamics in the lower thermosphere, ion upflow, and aurora phenomena. In the result of these activities, 29 papers have been published for 4 years.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Nagoya University, 18403010

火山噴煙のリモートセンシングに関する新手法の開発
科学研究費助成事業
2006 - 2008
橋本 武志, 寺田 暁彦, 中村 卓司, 高橋 幸弘
20年度は, 本研究課題の最終段階として, 2008年10月に再び阿蘇中岳火口でラマンライダーとスペクトルカメラによる噴煙水蒸気観測を行った. 今回は, 前回までの阿蘇での観測と登別大湯沼での観測をふまえ, 火口湖から蒸発する水蒸気と, 噴気口からまとまって放出されている水蒸気とを区別できるように工夫した. 具体的には, ライダーのビームを水平方向にスキャンして, 水平面内での水蒸気分布を求めた, 別途暗視カメラで上昇速度を測定し, 水蒸気フラックスを算出することができた. これにより, 湖面からの蒸発と噴気水蒸気とを区別することができ, 本課題の当初の目標のひとつであった湖面蒸発率の正確な推定を達成することができた.
スペクトルカメラについては, 新規の試みであったこともあり, 測定手法の模索に終始したが, 本研究課題によって一定の見通しが得られた. 800nm近辺の赤外吸収帯を用いることにより, 大気水蒸気による吸収の影響を抑えながら, 火山起源の水蒸気による赤外吸収を捉え得ることを実証できた, ただし, 背景光(太陽光)と火山噴煙との位置関係や気象条件による制約が大きいことが問題点として残っている. また, 野外での即時データ処理方法や機器の操作性などの面で, さらに改良すべき点もある.
2008年9月には, 代表者と連携研究者が集まり, 3年間の到達点と今後のステップに向けた改良点について議論した. その結果, 来年度以降もライダーおよびスペクトルカメラを用いた火山ガス研究を発展的に継続することを確認し, さらなる研究目標に必要な装置のスペックに関する青写真を作った.
日本学術振興会, 萌芽研究, 北海道大学, 18654075

地球起源ガンマ線の生成メカニズムの解明
科学研究費助成事業
2006 - 2008
高橋 幸弘, 藤原 均, 村田 功
米国NASAのガンマ線天文台衛星BATSE/CGROは、地球起源のガンマ線現象TGFs(Terrestrial Gamma-ray Flashes)を検出し、TGFとVLF/ELF帯の放電電波放射の同定に成功した。さらに、2002年に打ち上げられたREHSSI衛星によって、BATSEを遙かに上回る頻度でTGFが大量に観測され、エネルギーは最高で20-40eVに達することが明らかになった。その後、地上観測によるsfericsとの関係が精力的に検証されたが、TGFを引き起こす雷放電の性質は未解明な部分が多い。本研究では、RHESSIによって観測された500以上にのぼるTGFイベントと、東北大学が有する全球的なELF電波観測ネットワークによるsfericsデータを詳細に比較・検討し、TGFを発生させる雷雲活動の条件について明らかにする。18年度は、RHESSIによって観測された、特に特徴的なTGFイベントについて、同時刻に発生したELF波形を詳細に検討し、その他のイベントについてもデータベースの作成を進めた。その結果、大規模なTGFであっても必ずしも大規模落雷に伴うものでないという性質があらためて確認された。また、ISUAL衛星による雷放電の光学観測データから、TGFの相対的な発生確率の世界分布を明らかにした。さらに、アジア地域の集中観測キャンペーンの準備のため、雷放電の地上観測装置を台湾・台南市の国立成功大学屋上に設置した。海外の関連研究者との打合せと成果発表のために、シンガポールでのAOGS、北京でのWPGM、ドイツでのEuroplanetの各国際会議に出席した。
日本学術振興会, 基盤研究(B), 東北大学, 18403009

マイクロサテライトが拓くスプライト及び雷放電逃走電子の科学
科学研究費助成事業
2005 - 2008
高橋 幸弘, 坂井野 健, 吉田 和哉, 中西 洋樹, 高島 健, 田口 真
雲地上間の雷放電に伴う上空放電のひとつであるスプライトと呼ばれる現象は、1990年の最初の報告以来、精力的な研究が、観測、理論の両面から続けられている。しかし、これまでの地上観測ではスプライトを真下から見ることができないため、その水平構造については三角測量観測による数例しか調べられていない。一方、高エネルギー電子によって放射される地球ガンマ線が、雷雲活動に同期して人工衛星で観測されている。本研究では、CMOS及びCCDイメージャーとガンマ線センサーを搭載した、スプライト・地球ガンマ線観測専用のマイクロサテライトを開発、打ち上げ、それらの解明を目指す。検討の結果、本計画では、衛星を50cm立方、40kg級に変更することとした。2006年度は、以下の機器開発、校正、環境試験を実施するとともに、TLEおよびTGF観測戦略を作成するために、それらの地上および衛星観測データの解析を行い、海外研究者と議論する機会をもった。
1.搭載機器の製作・環境試験・校正
2005年度に引き続き、CMOS及びCCDを用いた超小型・軽量のイメージセンサーの製作・環境試験、及び校正を行い、ソフトウェアも含め、フライト品の製作に目途をつけた。また、米国カリフォルニア大学サンタクルズ校のスミス博士の助言に基づき、ガンマ線センサーの最終的な仕様を確定した。
2.衛星BUSの設計・開発および環境試験
BUSの最終設計を完了し、各パーツのフライト部品の仕様決定・購入を行った。必要部品を購入して構造モデルを製作し、振動試験を実施した。
3.海外研究者との打合せおよび成果発表
10月にフランスを訪れ、同様の衛星計画(打上は本計画の3年後)を持つフランスチームと会合を持ち、観測戦略についての意見交換を行った。また、12月のAGU(米国)学会に参加し、研究経過の発表(招待講演)と、海外研究者(スミス博士及びイナン教授他)と議論を行った。
日本学術振興会, 基盤研究(A), 東北大学, 17204042

衛星と地上観測による雷雲上方の放電発光現象の研究
科学研究費助成事業
2006 - 2007
福西 浩, 高橋 幸弘, 藤原 均, 村田 功
1989年に雷放電による中間圏大気の発光現象スプライトが発見されて以来、この10数年間に地上観測が続々と行われ、スプライトの他にも様々な過渡発光現象(TLE)が存在することが分かってきた。しかしこれまでの地上観測は限られた地点での観測であり、海上での観測もなかったことから、グローバルな発生分布を知ることができなかった。本研究では、2004年5月に打ち上げられたFORMOSAT-2衛星に搭載ISUAL観測器による雷放電発光現象のグローバル観測に基づき、TLE発生を支配する気象および雷雲活動条件と、発生機構の詳細を明らかにする。そのために、気象衛星データおよび地上ELF/VLF・光学観測データの解析結果や数値シミュレーションの結果を統合していく。平成18年度は、以下の成果が得られた。
1.衛星による発光現象のグローバル観測とデータ解析:FORMOSAT-2衛星搭載のアレイフォトメータの機能と取得データを定期的にチェックし、良好な観測データを得た。それらを解析した結果、TLEの世界発生分および雷放電数に対する発生確率分布を世界で初めて明らかにした。
2.ELF/VLF観測とデータ解析:世界4カ所(女川観測所、南極昭和基地、北極のキルナ、米国カリフォルニア州)に設置・運用しているELF観測網と国内のVLF受信機を運用し、得られたELF/VLFデータの解析を行った。特に、落雷位置決定精度の向上に努め、4倍以上の改善を達成した。またISUALデータと比較し、ELF波形からみたTLE発生条件について考察を行った。
3.地上光学観測装置の開発:地上観測を充実させるために、主に光学観測装置の開発を進めた。
4.数値シミュレーション:観測データの解析から得られる発光現象の発生条件をパラメータとして用い、TLEの時空間構造と化学的効果についてシミュレーションを行い、NOXの異常増加を初めて示した。
日本学術振興会, 基盤研究(B), 東北大学, 18340149

Observational study of Venus atmosphere dynamics
Grants-in-Aid for Scientific Research
2005 - 2007
NAKAMURA Masato, IMAMURA Takeshi, TAKAHASHI Yukihiro
Planetary atmospheres were observed many times using large telescopes, such as the Subaru telescope at Hawaii, and new knowledge about composition and movement of the Venus atmosphere were acquired. Moreover, new observation equipment for planetary probes, such as an infrared detector array, was developed. Techniques to analyze imaging-spectral data of planetary atmospheres were studied, and applied to the data obtained so far. The data analysis system for the Japanese Venus atmosphere mission 'PLANET-C' or 'Venus Climate Orbiter' has been developed. More specifically, the following studies have been performed.
(1) To study the photochemical reaction chain in the Venus atmosphere, the spatial distribution of HCl in the Venus stratosphere was observed using the IRTF telescope at Hawaii. The roloe of HCl as a catalyst reaction was constrained.
(2) The thermal radiation from the cloud top of Venus was observed at middle infrared wavelengths using the Subaru Telescope and the IRTF telescope, and the temporal variation in the fine structures of the cloud top was detected for the first time. Information on the thermal convection in the cloud layer and the characteristics of planetary-scale waves were acquired.
(3) Instruments onboard planetary probes need to have tolerance to the energetic radiation in space. A new infrared detector was developed and tested for such radiation environment.
(4) The technique of deriving wind velocities from successive cloud images of high spatial resolution was studied for future ground-based observations or spacecraft missions. The wind determination accuracy of several meters per second, which is needed in meteorological study, was achieved.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Japan Aerospace Exploration Agency, 17340147

Study on planetary atmospheres and plasmas by a balloon-borne telescope
Grants-in-Aid for Scientific Research
2005 - 2006
TAGUCHI Makoto, YOSHIDA Kazuya, NAKANISHI Hiroki, TAKAHASHI Yukihiro, SAKANOI Takeshi
This research has promoted the ongoing development of a balloon-borne telescope system for remote sensing of planetary atmospheres and plasmas. In this system, a Schmidt-Cassegrain telescope with a 300-mm clear aperture is mounted on a gondola whose attitude is controlled by control moment gyros, an active decoupling motor, and a Sun sensor. The gondola can float in the stratosphere for periods in excess of 1 week. A pointing stability of 10 arcsec/sec will be achieved via the cooperative operation of the following three-stage pointing devices: a gondola-attitude control system, two-axis telescope gimbals for coarse guiding, and a tip/tilt mirror mount for guiding error correction. The tip/tilt mirror is controlled by a real-time correction signal from a position-sensitive photomultiplier tube. Video images of an object in near-infrared and ultraviolet are obtained by analog and digital CCD video cameras, respectively. Power is supplied by solar cell panels and Ni-MH batteries, of which low temperature characteristics have been tested. A pressurized cell contains two PCs, DC/DC converters, pre-amplifiers and a high-voltage power supply for a tip/tilt mirror mount. System performance under a low-temperature and low-pressure condition has been confirmed by a thermal vacuum test. ESRANGE in Kiruna, Sweden was investigated for a candidate launch site of a future experiment in the Arctic. The first target for the system is Venus. Wind vectors in the Venusian upper atmosphere will be derived from the tracking of cloud patterns observed in the ultraviolet and near-infrared regions. An experiment designed to test the system performance is scheduled to take place in Japan during June 2007, and a long-duration flight in the Arctic is scheduled for 2008.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), National Institute of Polar Research, 17540426

Evaluation of the effects of global lightining activity on the middle/upper atmosphere and atmosphere and the ionosphere/magnetosphere
Grants-in-Aid for Scientific Research
2003 - 2005
TAKAHASHI Yukihiro, FUKUNISHI Hiroshi, MURATA Isao, FUJIWARA Hitoshi, MAKITA Kazuo, TAGUCHI Makoto
In this research we have carried out optical and radio wave observations of lightning- induced TLEs (transient luminous events) in the middle and upper atmosphere, including sprites and elves, under international collaboration in order to clarify the generation mechanisms of TLEs and to understand their global effects both in electromagnetic and chemical point of view.
1. Sensor installation and steady observation in Scandinavia
We visited ESRANGE observatory in Kiruna, Sweden in 15 FSY and carried out maintenance/ of CCD camera, installation of ELF and VLF receivers. In 16 and 17 FSY, we visited there again and carried out the maintenance and adjustments. The continuous data acquisition have been carried out up to now successfuly.
2. Extension and steady operation of world wide ELF network
In addition to the ELF systems both at Syowa, Antarctica and Onagawa, Japan, we installed 2 more systems at Kiruna (FSY 15) and at Santa Cruz, California, USA (FSY 17). The system consisting of 4 stations is quite unique and the most useful network for lightning detection in estimating charge moment of lightning.
3. Optical measurements of TLEs by FORMOSAT-2/ISUAL and data analysis
Taiwanese satellite FORMOSAT-2 was launched successfully on 20 May, FSY of 16. FORMOSAT-2 carries 3 sprites/lightning optical equipments and its health is in good condition since the start of observation. The analysis shows the first global distribution of TLEs (sprites, elves) and absolute electron energy in TLE for the first time.
4. Estimation of chemical effects of TLEs and lightning based on computer simulation
We carried out the computer simulations to examine the physical mechanisms and to estimate the chemical effects on the ambient atmosphere. In addition, we visited University of Bremen, Germany and discussed about comparison between the chemical measurement with satellite and ELF network data.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Tohoku University, 15403011

Energy coupling between atmosphere and inosphere via electrical descharge
Grants-in-Aid for Scientific Research
2001 - 2003
FUKUNISHI Hiroshi, FUJIWARA Hitoshi, MURATA Isao, TAKAHASI Yukihiro, YUMOTO Kiyofumi, SAKANOI Takeshi
In order to investigate the generation mechanisms of luminous events in the middle and upper atmosphere induced by lightning discharge and their relationship to the parental thunderstorm activity, some observation campaigns and continuous measurements have been carried out using a multipoint observation system composed of several optical instruments and VLF-ELF radio wave sensors. Detail analysis and computer simulations based on the observation data clarified following issues : (1) Thunderclouds producing sprites around Japan in wintertime are classified into 4 types and the apparent feature of sprites depends on the geographic location. (2) Cloud to ground discharge generating winter sprites in Japan occurs in the most active convective region of the thundercloud. (3) Considering the appearance of intermittent radio wave in VLF range just after sprite optical emissions, it is suggested that hybrid type discharge consisting of cloud-to-ground and intra-cloud discharges is relating to sprite generation. (4) Number of columns in a sprite event well correlates to the peak current of the parent lightning while the vertical length of column shows good correlation with charge moment of the cloud to ground lightning. (5) The average upper and bottom heights and the horizontal extent of sprite halo are 88 km, 73 km and 86 km, respectively. The estimated electron energy is 6 ?23 eV. (6) The average number of sprite evens for a day is estimated to be 720 based on the ELF measurements. (7) The lightning energy shows variation with a time period of 27.9 days, which may be caused by solar activity. (8) Sprites and sprite halo could be major sources of O(D) in the nighttime mesosphere.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Tohoku University, 13304037

Ground-based infrared measurements of the Venus atmosphere with a Fourier transform spectrometer and a laser heterodyne spectrometer
Grants-in-Aid for Scientific Research
2000 - 2002
MURATA Isao, FUKUNISHI Hiroshi, FUJIWARA Hitoshi, TAKAHASHI Yukihiro, OKANO Shoichi
A new optical observation system for planets with 60 cm telescope was installed in Iitate, Fukushima in 1999. The purpose of this study is to observe Venus atmosphere with the infrared spectrometers of this system.
In 2000, the sensitivity of the InGaAs detector of the Fourier transform spectrometer (FT-IR) was checked using black body. The alignment of the acousto-optical spectrometer of the laser heterodyne spectrometer was adjusted to improve the wavenumber resolution.
In 2001, FT-IR was set at Iitate and the spectra of the Venus between 0.9 and 1.7 μm were measured as a test observation. A new InSb detector for longer wavelength than 2 μm were installed to the FT-IR.
In 2002, Venus atmosphere was observed with InGaAs detector of FT-IR on 8 days from September 2002 to January 2003. O_2 emission of Venus atmosphere at 1.27 μm were detected on November 29, December 11, 14, and 28. Jupiter spectrum were measured on December 7 and CH_4 absorption of Jupiter atmosphere were detected. Venus spectrum were also measured with InSb detector but there was strong thermal emission of the instruments at wavelength longer than 4μm. This thermal emission should be reduced with optical filter or some other methods.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Tohoku University, 12640429

Studies on magnetospheric boundary processes based on magnetic field and aurora observation in the northern and southern polar caps
Grants-in-Aid for Scientific Research
2000 - 2002
FUKUNISHI Hiroshi, SAKANOI Takeshi, TAKAHASHI Yukihiro, OKANO Shoichi, TAGUCHI Makoto, YAMAGISHI Hisao
In order to clarify the interaction between the solar wind and the magnetosphere of the Earth, magnetospheric boundary processes were investigated, making use of 6 non-manned automatic geophysical observatories (AGO) located in the interior of the Antarctic Continent. Comprehensive analysis was carried out, combining data recorded by AGO equipments, such as magnetometers, aurora imagers, riometers and VLF receivers, and solar wind and solar activity data obtained by spacecrafts as well as HF radar data at Syowa station. Results including some important and new findings are as follows:
1) Conjugate TCV (traveling convection vortices) events moving sunward in both hemispheres were found and its physical mechanisms were investigated in detail.
2) Transient ionospheric disturbances relating to the TCV were found. It is shown that the disturbances are consequence of non-linear processes in F-region caused by 3-D current system and auroral particle precipitations.
3) Automatic detection algorithms for MIE (magnetic impulse event) and for TD (tangential discontinuity) were developed successfully.Using these algorithms,it was found that occurences of MIE and TD show correlation in seasonal variation.
4) A tecchnique to calculate the TD arrival time using data obtained by one spacecraft was developed.
5) Quantitative model for TCV phenomena considering conjugate condition in the magnetosphere-ionosphere coupling processes was constructed.
6) 3-D MHD simulation was conducted to understand the current generation mechanisms associated with TCV. The results succeeded in reproducing typical TCV phenomena.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Tohoku University, 12573007

Observation of Jovian Visible Aurora and its Generation Mechanism
Grants-in-Aid for Scientific Research
2000 - 2001
WATANABE Shigeto, TAKAHASHI Yukihiro, KURAMOTO Kiyoshi, HAYASHI Yoshiyuki
We have built an optical observation system of Jovian visible aurora and airglow, which consists of CCD and narrow band filter on ground-based telescope. The emissions have never been measured from ground. We have carried out the observations by use of Rikubetsu 110cm telescope, lidate 60cm telescope and Hokkaido University 10cm telescope from 1999 to 2001. We have also developed an imaging processing system that analyzes the image of Jupiter taken with short exposure time and integrated. We found some emissions in the northern region of Jupiter. Our system may be able to apply to detect very weak signals from planets or airglow.
We have investigated theoretically the atmosphere of Jupiter as well as Venus, Earth and Mars. The results suggested that the interactions with clouds and plasma are important to planetary atmospheres. Especially, at high altitudes the ion-drag effect must be considered in the planetary upper atmospheres.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), HOKKAIDO UNIVERSITY, 12640428

Processes of optical and radio emissions in the upper atmosphere induced by cloud to ground discharge
Grants-in-Aid for Scientific Research
1998 - 2000
FUKUNISHI Hiroshi, MURATA Isao, TAKAHASHI Yukihiro, WATANABE Shigeto, NAGANO Isamu, SAKANOI Takeshi
In 1990 a discharge phenomenon from the stratosphere to the ionosphere was found during the tcst observation of a low-light TV camera employed by University of Minnesota. Since this discovery a lot of observations from ground, aircraft and space shuttle have been carried out. It is found that these kinds of optical emissions in the stratosphere, mesosphere and lower ionosphere, now called sprites and elves, are induced by an intense cloud to ground discharge and that the phenomena are accompanied by strong radio and gamma ray emissions. Optical emissions of sprites and elves are considered to be caused by an excitation via collision processes between atmospheric molecules/atoms and electrons that are energized by quasi-static electric field or electromagnetic impulse generated by a cloud to ground discharge. We estimated the electron energies based on the spectral observations with high-speed photometers. It is found that electron temperature has a peak of 3-25 eV for carrot-like sprites and 2-14 eV for column type sprites at the onset of the optical emission. In a body of carrot-like sprites the electron temperature tends to increase as altitude decreases with a local peak of 12-20 eV at an altitude of 〜80 km that corresponds to gap between hair and head region of sprites. On the other hand, it is confirmed that elves are caused by a negative cloud to ground discharge as well as a positive one. Electron energy of elves was found to reach up to 40 eV, which implies a strong ionization in the lower ionosphere. We conducted optical observation in Japan and showed the occurrences of sprites and elves in winter for the first time in the world. We also analyzed the "sprite halo" which appears as a diffuse fashion with a disk-like shape and revealed its time-space structure of luminous intensity and electron temperature.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A)., Tohoku University, 10304036

惑星大気研究を推進させるための基礎調査
科学研究費助成事業
1999 - 1999
渡部 重十, 今村 剛, 高橋 幸弘, 品川 裕之, 中村 正人, 林 祥介
21世紀における大気圏・電離圏・磁気圏物理学の一つの目標である,地球・惑星大気圏の基本的成り立ちや構造・力学・大気と太陽風の相互作用さらに生命圏としての惑星大気に関する普遍的・本質的理解へ向けて,現時点での既存知識・理論的枠組・観測手段などを集約・整理し,問題点を明らかにすることにより惑星探査を含む惑星大気研究の将来像を探るための基礎調査を実施した.以下のような5項目について,それぞれの研究の現状と今後の動向を集約・検討した.
惑星上昇大気と太陽風との相互作用: 上層大気の惑星空間への散逸,逆に惑星空間から惑星大気への物質流入,太陽変動に対する惑星大気の応答,太陽風との相互作用などに関与する電磁気的素過程
惑星大気光化学: 惑星大気圏内で放射や相変化などエネルギー収支に関与する諸物質の,生滅を支配する光化学的素過程,ならびに輸送を支配する力学的素過程
惑星大気力学: 超高速気流の生成・維持のメカニズム,濃密(高圧高温)大気の力学など,地球上に存在しない特性や振舞をする大気に関する力学的枠組の構築
惑星大気の起源: 各惑星大気の組成・構造の分化したプロセスに関する,太陽進化論・太陽系起源論・惑星形成論を背景にした様々な議論の整理
惑星大気観測: 探査とその推進戦略: 探査機・地球軌道上・地上からなどの観測技術に加え,他の地球惑星科学諸分野の進展状況,さらに国内外の技術的革新,経済的制約,社会的許容度などの調査・検討
生命の起源: 生命の起源に関する現状での理解と問題点,生命探査を含んだ惑星探査計画について調査・検討
8月27,28日に東京大学で約60名による「調査報告研究会」,9月24,25日に京都大学で約50名による「調査報告研究会」,3月6,7日に北海道大学で90名による「調査・検討と総合会議を開催した.検討結果は,今後の研究推進の指針ともなるべきものであり,「報告書」としてとりまとめる.
日本学術振興会, 基盤研究(C), 北海道大学, 11894011

Joint Study on the M-I Coupling in the Southern Polar Cap
Grants-in-Aid for Scientific Research
1997 - 1999
FUKUNISHI Hirishi, OKANO Shoichi, YAMAGISHI Hisao, SATO Natsuo, TAKAHASHI Yukihiro, TAGUCHI Makoto
Data obtained by Automatic Geophysical Observatories (AGOs) located at Antarctic high latitude areas in the period of 1993 - 1997, such as aurora image, geomagnetic field, CAN, and VLF waves, have been analyzed carefully in order to investigate the mechanisms of aurora and geomagnetic activities in polar cap region, comparing with Super DARN HF radar network and satellite data. The most important findings are as follows : 1) Pc 1 bursts occur in polar cap region as well as cusp and cleft region, accompanying an impulsive geomagnetic variation caused by geomagnetic reconnection. 2) Pc 3 waves are frequently observed during daytime near 70 degree in geomagnetic latitude, while around 80 degree local time dependency of Pc 3 is comparably small. Based on the comparison with interplanetary magnetic field (IMF) it is inferred that Pc 3 source is located at upstream of shock front and the Pc 3 penetrates into the magnetosphere from subsolar region for small cone angle case while from high latitude in the tail region or low latitude boundary layer (LLBL) for large cone angle case. 3) Dynamic spectrum of Pc 5 in geomagnetic latitude range of 72 - 74 degree sometimes shows an arch structure caused by odd resonance wave. The occurrence frequency of Pc 5 becomes large in northward IMF condition, which implies relationship between generation of Pc 5 and geomagnetic reconnections. 4) Magnetic impulse event (MIE) occurs in the convection reversal boundary of 4 cell pattern observed in the case of northward IMF. MIE travels westward by 60 degree in longitude at a speed of 2 km/sec.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B)., TOHOKU UNIVERSITY, 09044053

Studies of the morphology and the hetelogeneous reactions of Arctic PSC over Spitsbergen
Grants-in-Aid for Scientific Research
1997 - 1999
SHIBATA Takashi, OSADA Kazuo, MATSUNAGA Katsuji, IWASAKA Yasunobu, TAKAHASHI Yukihiro, HUKUNISHI Hiroshi
Many PSC events were observed by the lidar observations at Ny-Aalesund, Svalbard (79゜N, 12゜W). The sandwich structure found in the vertical profile of PSC, which was frequently observed when the stratospheric temperature was lowered near the frost point, is very characteristic.
The enhancement of PSC was observed when stratospheric temperature decreased near the frost point. The peak value of the backscattering ratio of the PSC is 5 to 8, and the depolarization ratio is near zero. The peaks of depolarization were found at the top and bottom sides of the PSC scattering layer. In other words, a liquid layer of PSC was between the solid layer (sandwich). The backscattering did not enhance at the depolarization peaks.
The scattering and depolarization are inversely correlated in the sandwich structure for the vertical direction. This inverse correlation was observed not only in the sandwich structure, but also in the almost all the PSC events. There was few events when the scattering and depolarization were increased simultaneously.
The numerical simulations of the lidar observations show some important suggestions for the microphysical processes of PSC. The simulations indicate that the parts of the characteristics of PSC can be explained by the ternary solution of H2SO4/HNO3/H2O. The observations were well simulated only when the number concentration of solid particles are between 10ィイD1-3ィエD1 and 10ィイD1-2ィエD1 /cc.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A)., Nagoya University, 09041104

北方圏における地球環境変動に関する共同研究
科学研究費助成事業
1996 - 1998
田中 正之, SENTMAN D.D., 大竹 政和, 坂野井 健, 佐藤 春夫, 福西 浩, 吉本 和生, 長谷川 昭, 高橋 幸弘, WYSS M., MUCNUTT S.R., STRINGER W.J, BISWAS N.N., HANSEN R.A., SHAW G.E., BENNER R.L., STAMNES K., 田口 真, AKASOFU S.ーI, DEEHR C.S., 青木 周司, 早坂 忠裕, 川村 宏, 中澤 高清, SMITH R.W., 渡部 重十, 花輪 公雄
東北大学理学部・同理学研究科とアラスカ大学フェアバンクス校との部局間協定にもとづき、本年度の北方圏における地球環境変動に関する共同研究は、(1)オーロラと超高層大気の研究、(2)雷放電発光現象の研究、(3)成層圏オゾン層の研究、(4)地震・火山の研究を中心に行なった。まず、(1)オーロラと超高層大気の研究では、通信総合研究所が開発したプロトンオーロライメージャーを1999年2月にアラスカ大学地球物理学研究所ポーカーフラット観測所に設置し観測を行った。さらに昼側カスプ領域のオーロラのロケット・地上同時観測のために東北大学のプロトンオーロライメージャーを1月にノルウェー・スバールバルに設置し、共同観測を実施した。これらの観測から得られたデータの共同解析を現在行っている。(2)雷放電発光現象の研究では、1998年7月〜8月にコロラドでスプライト・エルブス発光現象の共同観測を実施した他、1998年5月にアラスカ大学より1名を招へいし、1997年度に得られた雷発光現象データの共同解析を行った。(3)成層圏オゾン層の研究では、1997年2月〜5月の間にポーカーフラットで東北大学のレーザーヘテロダイン分光計を用いて実施したオゾン、一酸化二窒素、メタン観測のデータとADEOS衛星データの比較を行った。(4)地震・火山の研究では、アラスカ大学地震観測ネットワークで得られたデータと東北大学地震観測ネットワークで得られたデータの共同解析を実施し、発震メカニズムや地震予知のための研究を行った。
日本学術振興会, 国際学術研究, 東北大学, 08045020

Lightning Induced Optical Emissions in the Middle Atmosphere
Grants-in-Aid for Scientific Research
1996 - 1997
WATANABE Shigeto, YUMOTO Kiyofumi, TAKAHASHI Yukihiro, FUKUNISHI Hiroshi, LYONS W.A., INAN U.S.
Observations of optical phenomena at high altitude above thunderstorms using a multichannel high-speed photometer and image intensified CCD cameras were carried out at Yucca Ridge Station (40゜40'N, 104゜59'W), Colorado. The new measurements indicate that diffuse optical flashes with a duration of <1ms and a horizontal scale of 〜100-300km occur at 75-105km altitude in the lower ionosphere just after the onset of sprites. Here we designate these events as "elves" to distinguish them from "red sprites". This finding is consistent with the production of diffuse optical emissions due to the heating of the lower ionosphere by electromagnetic pulses generated by lightning discharges.
Optical and search coil magnetometer data were obtained from the SPRITES'96 campaign carried out at Yucca Ridge Field Station, Colorado in July 1996. We have presented clear evidence for the excitation of ULF transients with their dominant power at 1-2 Hz by strong lightning discharges producing elves and sprites without preceding elves and the case of sprites with preceding elves. In the former case, damped quasi-sinusoidal oscillations commence impulsively at the onset of sprites, while in the latter case quasi-sinusoidal wavelets with a duration of 〜3 s are excited, and elves and sprites occur within each wavelet. It is lucky that these ULF transients are due to the nonlinear excitation of the ionospheric Alfven resonator by strong lightning discharge.
Japan Society for the Promotion of Science, Grant-in-Aid for international Scientific Research, Tohoku University, 08044053

A study on planetary atmosphere by the laser heterodyne spectroscopy
Grants-in-Aid for Scientific Research
1995 - 1997
FUKUNISHI Hiroshi, TAKAHASHI Yukihiro, TAGUCHI Makoto, WATANABE Shigeto, OKANO Shoichi
Laser heterodyne spectroscopy is the most powerful technique for remote sensing of planetary atmosphere because of its high spectral resolution, high spatial resolution, and high signal-to-noise ratio. In this study, a new tunable diode laser heterodyne spectrometer with a wide spectral range has been developed for planetary atmosphere observation.
First, a small-sized laser heterodyne spectrometer with four tunable laser diodes was developed to covert the infrared emission or absorption spectra from planetary atmosphere into the radio wave frequency range. An acousto-optic radio spectrometer was also developed to obtain the spectra in the converted radio frequency range.
Next, an optics for interface with the infrared telescope of the Institute of Space and Astronautical Science was made to observe the Venusian atmosphere for testing the instrument. However, observation scheduled in November 1997 was not carried out because of the trouble of the infrared telescope. Then the test observation was carried out with the infrared simulator of National Astronomical Observatory in April 1998. However, the infrared spectra of the Venusian atmosphere were not obtained because of bad weather.
Finally, laboratory test and observations of the Earth's atmosphere using the sun or the moon as a light source were performed to check the performance of the developed instrument. These tests revealed that the signal-to-noise ratio of the spectrometer is not enough, while the moon observation demonstrated that weak infrared spectra can be measured with this instrument. The instrument is now under improvement and test observation of the planetary atmosphere will be performed again.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Tohoku University, 07404025

雷放電に伴う中間圏・下部電理圏発光現象の研究
科学研究費助成事業
1996 - 1996
高橋 幸弘
1990年以降、雷放電に伴う中層大気及び超高層大気における発光現象(スプライト、ブルージェット、エルブズ)は世界的な注目を集め、精力的な研究が行われてきた。しかしこれまでの光学観測の時間分解能はCCDカメラのフレームレート程度(17ミリ秒)であり、継続時間が数ミリ秒以下であるスプライトやエルブズの時間空間構造を捕えるには甚だ不十分であった。本研究課題ではそれらを解明するために、我々が開発した多チャンネル超高速フォトメータの観測データを、CCDカメラの画像データとあわせて詳細に比較検討した。フォトメータデータの解析には主にワークステーションを、画像解析には新たに購入したパーソナルコンピュータを用いた。
昨年度と本年度の観測で得られた約250例のスプライト及びエルブズのデータの解析から、以下の事実が初めて明らかになった。
1.雷放電直後(数ms〜数10ms以内)に中層及び超高層大気でおこる発光現象には、スプライトのみの場合、エルブズのみの場合、スプライトとエルブズの両方が見られる場合がある。
2.エルブズは水平方向に長い円盤状(〜300km)に現われ、通常中心部が明るくなっている。継続時間は約1ミリ秒、伝播方向は常に下向きで、伝播速度は上部(〜1×10^5km/s)に比べ下部(2-4×10^4km/s)では低下する。
3.明るいエルブズを伴う場合、スプライトは水平に広がった10本程度の明るい縦筋から成る。初めにエルブズが現われ、続いて短時間の発光が下向きに伝搬し、最後に中心部から上下両方向に増光領域が拡がる。
4.エルブズの非常に弱い場合、スプライトは微細構造を有する太い1本の縦筋から成り、上部のやや広がった逆三角形(人参状)をしている。最初に短時間の発光が数万km/sで低高度から高高度に向かい、続いて低高度に強い発光が起こり、最後に高高度が再び増光する。継続時間は多くの場合、2-4msである。
日本学術振興会, 奨励研究(A), 東北大学, 08740383

Joint study on Polar Cap Disturbances Using AGO Network
Grants-in-Aid for Scientific Research
1995 - 1996
FUKUNISHI Hiroshi, TAKAHASHI Yukihiro, TAGUCHI Makoto, WATANABE Shigeto, YAMAGISHI Hisao, SATO Natsuo, HAYASHI Kanji, ARAKI Tohru, LANZEROTTI L.J, INAN U.S, ROSENBERG T.J, MCLENNAN C.G, ENGEBRETSON M.J, DOOLITLE J.H, WOLFE A
Auroras and geomagnetic disturbances have been investigated at Automatic Geophysical Observatories (AGO) in the polar cap region where nobody had installed the instruments to observe those phenomena. We developed the instruments to observe auroras and geomagnetic disturbances and operated at 6 AGO stations with corroborations with scientists of the United States. The activities are as follows.
1. Developments of search coil magnetometer and photometer
We made two search coil magnetometers for back up of magnetometers operated at AGO stations. We also made photometers with very high data sampling.
2. Tests of search coil magnetometer and photometer
Fukunishi, Takahashi and Fujito checked magnetometers and photometers at Yucca Ridge of Colorado, USA with a group of Stanford University. We obtained good sensitivities to observe auroras and geomagnetic disturbances at AGO stations.
3. Set up at AGO station
On October, 1995, we set up our search coil magnetometers for AGO-5 and AGO-6 stations at MacMurdo station of Antarctica.
4. Analyzes of AGO data
On December, 1995, Fukunishi and Takahashi visited Stanford University to analyze the data of auroras, magnetic fields and ELF-VLF waves obtained at AGO stations. On December, 1996, Fukunishi and Katsuyama visited Stanford University again to analyze the AGO data in detail. Fukunishi visited Laboratory of Antarctica of UK to analyze the AGO data and to have discussions on August, 1996. Prof.Engebretson of Augsburg University visited Tohoky University to compare between his obtained flux gate magnetometer data and our search coil magnetometer data.
5. Discussions of publication and future work
Fukunishi visited Church University of UK to present our results and future plan on August, 1996 and stayd for one week. Fukunishi and Katsuyama visited Stanford University to discuss future plan on December, 1996.
We found new results from the detailed analyzes of AGO data. One of the interesting results is the correlations between magnetic impulse events (MIE) and Pc 1 bursts. We analyze the events in detail with Dr.Lanzerotti of Bell Laboratory and Prof.Engebretson of Augsburg University who indicates the good correlations between MIE and ELF-VLF waves. All instruments are still working well at 6 AGO stations. We are investigating our AGO data with satellite and radar data. Those results will provide us more large progress in understanding polar cap phenomena.
Japan Society for the Promotion of Science, Grant-in-Aid for international Scientific Research, TOHOKU UNIVERSITY, 07044053

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