Researcher Database

Yukihiro Takahashi
Faculty of Science Earth and Planetary Sciences Cosmosciences

Researcher Profile and Settings


  • Faculty of Science Earth and Planetary Sciences Cosmosciences

Job Title

  • Professor


J-Global ID

Research Interests

  • 雷放電   スプライト   エルブス   電離圏   TLE   ELF   地球ガンマ線   超高層大気   中間圏   TGF   中層大気   北欧   地上観測   磁気圏   リモートセンシング   台風   ISUAL   大学衛星   ダウンバースト   インドネシア   ブラジル   超小型衛星   スウェーデン   豪雨災害   発光現象   北欧観測   マイクロサテライト   人工衛星   ミャンマー   大気化学   

Research Areas

  • Natural sciences / Space and planetary science
  • Environmental science/Agricultural science / Environmental dynamics
  • Social infrastructure (civil Engineering, architecture, disaster prevention) / Disaster prevention engineering
  • Social infrastructure (civil Engineering, architecture, disaster prevention) / Disaster prevention engineering
  • Natural sciences / Atmospheric and hydrospheric science
  • Natural sciences / Solid earth science
  • Humanities & social sciences / Geography

Academic & Professional Experience

  • 2009 - 2015 Hokkaido University

Research Activities

Published Papers

  • 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) 1880-5981 2018/12/01 [Refereed][Not invited]
    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.
  • Katsuhama, N, M. Imai, N. Naruse, Y. Takahashi
    J. Remote Sensing Letters 9 1186 - 1194 2018 [Refereed][Not invited]
  • 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 2169-897X 2015/05 [Refereed][Not invited]
    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.
  • Kozo Yamashita, Yukihiro Takahashi, Mitsuteru Sato, Hiromi Kase
    JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS 116 2169-9380 2011/02 [Refereed][Not invited]
    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.
  • 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 0148-0227 2010/09 [Refereed][Not invited]
    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.
  • Y. Takahashi, Y. Okazaki, M. Sato, H. Miyahara, K. Sakanoi, P. K. Hong, N. Hoshino
    ATMOSPHERIC CHEMISTRY AND PHYSICS 10 (4) 1577 - 1584 1680-7316 2010 [Refereed][Not invited]
    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.
  • Y. Takahashi, J. Yoshida, Y. Yair, T. Imamura, M. Nakamura
    SPACE SCIENCE REVIEWS 137 (1-4) 317 - 334 0038-6308 2008/06 [Refereed][Not invited]
    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.
  • 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 1364-6826 2003/03 [Refereed][Not invited]
    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.
  • The dynamics of the proton aurora in auroral breakup events
    Takahashi, Y, H. Fukunishi
    J. Geophys. Res. 106 45 - 63 2001 [Refereed][Not invited]
  • H Fukunishi, Y Takahashi, M Kubota, K Sakanoi, US Inan, WA Lyons
    GEOPHYSICAL RESEARCH LETTERS 23 (16) 2157 - 2160 0094-8276 1996/08 [Refereed][Not invited]
    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.

Conference Activities & Talks

  • Optical characteristics of elves observed by FORMOSAT-2/ISUAL and properties of parent lightning discharges  [Invited]
    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  Beijing, China
  • Characteristics of TLEs observed by ISUAL/AP onboard FORMOSAT-2  [Invited]
    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  San Francisco, US
  • SPRITE-SAT mission for sprites and TGFs studies  [Invited]
    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  Vienna, Austria
  • Lifetime and structures of TLEs captured by high-speed camera on board aircraft  [Invited]
    Y. Takahashi, Y. Sanmiya, M. Sato, T. Kudo, NHK Cosmic Shore Project, Y. Yair, S. A. Cummer
    American Geophysical Union 2012 Fall Meeting  San Francisco, US
  • Role and Scope of Asian Micro-satellite Consortium  [Invited]
    Yukihiro Takahashi
    34th Asia Conference on Remote Sensing “Applications of remote sensing technology on tropical peatlands”  Bali, Indonesia
  • A Scope of Asian Micro-satellite Consortium  [Invited]
    Yukihiro Takahashi
    IEEE Workshop on Geoscience and Remote Sensing 2013  Melaka, Malaysia
  • High frequency / precision disaster monitoring with micro-satellite constellation  [Invited]
    Yukihiro Takahashi
    UN World Conference on Disaster Risk Reduction 2015  Sendai, Japan
  • Collaborative Promotion of Micro-satellite Utilization by International Consortium  [Invited]
    Yukihiro Takahashi
    APRSAF-17  Manila, Philippines
  • Next-generation Earth Monitoring System with Micro-satellites and Ground-based Networks  [Invited]
    Yukihiro Takahashi
    17th Conference of the Science Council of Asia  Manila, Philippines


  • 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"  2014/09/10  [Not refereed][Not invited]
  • 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"  2014/09/10  [Not refereed][Not invited]
  • 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"  2014/09/10  [Not refereed][Not invited]
  • 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-  87  -105  2014/03  [Not refereed][Not invited]
    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.
  • TAKAHASHI Yukihiro  Journal of plasma and fusion research  90-  (2)  128  -131  2014/02/25  [Not refereed][Not invited]
  • TAKAHASHI Yukihiro  Journal of plasma and fusion research  90-  (2)  137  -140  2014/02/25  [Not refereed][Not invited]
  • 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"  2013/11/20  [Not refereed][Not invited]
  • Yamashita Kozo, Takahashi Yukihiro, Matsumoto Jun, Hamada Jun-ichi  Proceedings of the Society Conference of IEICE  2013-  (1)  2013/09/03  [Not refereed][Not invited]
  • Takahashi Y  Planetary People  21-  (3)  2012/09/25  [Not refereed][Not invited]
  • Takahashi Y, Sato M, Fukuhara T, Kurihara J, Nakajima K  Planetary People  21-  (3)  224  -228  2012/09/25  [Not refereed][Not invited]
  • Yamashita Kozo, Ohya Hiroyo, Tsuchiya Fuminori, Takahashi Yukihiro, Matsumoto Jun  Proceedings of the Society Conference of IEICE  2012-  (1)  2012/08/28  [Not refereed][Not invited]
  • 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  2012/05/10  [Not refereed][Not invited]
  • 高橋 幸弘  計測と制御 = Journal of the Society of Instrument and Control Engineers  51-  (5)  445  -448  2012/05/10  [Not refereed][Not invited]
  • 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  2012/04/05  [Not refereed][Not invited]
  • TAKAHASHI Yukihiro, FUKUHARA Tetsuya, KURIHARA Junichi  Technical report of IEICE. SANE  111-  (239)  33  -35  2011/10/10  [Not refereed][Not invited]
    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.
  • SAKAMOTO Yuji, KUWAHARA Toshinori, YOSHIDA Kazuya, TAKAHASHI Yukihiro  Mechanical Engineering Congress, Japan  2011-  "S192025  -1"-"S192025-3"  2011/09/11  [Not refereed][Not invited]
    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.
  • 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"  2011/01/27  [Not refereed][Not invited]
    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.
  • 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  [Not refereed][Not invited]
    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.
  • 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  [Not refereed][Not invited]
  • 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  2010/11/01  [Not refereed][Not invited]
  • Yoshida Kazuya, Shoji Yasuhiro, Sakamoto Yuji, Taguchi Makoto, Takahashi Yukihiro  Proceedings of the IEICE General Conference  2010-  (1)  "SS  -78"-"SS-79"  2010/03/02  [Not refereed][Not invited]
  • 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  2010/03  [Not refereed][Not invited]
    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.
  • Takahashi Yukihiro, Hoshino Naoya  Planetary People  18-  (4)  238  -241  2009/12/25  [Not refereed][Not invited]
  • 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-  2009/09/28  [Not refereed][Not invited]
  • 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  2009/06/25  [Not refereed][Not invited]
  • TAKAHASHI Yukihiro, KURAMOTO Kiyoshi  Planetary People  9-  (1)  33  -46  2000/03/25  [Not refereed][Not invited]

Educational Activities

Teaching Experience

  • 現代地球惑星科学概論1
    開講年度 : 2019
    課程区分 : 学士課程
    開講学部 : 理学部

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