小郷原 一智 (オゴハラ カズノリ)

OGOHARA Kazunori

写真a

職名

講師

研究分野・キーワード

惑星画像処理、大気の数値シミュレーション

ホームページ

https://sites.google.com/site/marsogohara/research

出身大学院 【 表示 / 非表示

  • 京都大学  理学研究科  地球惑星科学専攻  博士課程  2010年03月

取得学位 【 表示 / 非表示

  • 博士(理学)  京都大学  2010年03月

学内職務経歴 【 表示 / 非表示

  • 滋賀県立大学  工学部  電子システム工学科  講師   2019年04月 ~ 現在

  • 滋賀県立大学  工学部  電子システム工学科  助教   2013年04月 ~ 2019年03月

学外略歴 【 表示 / 非表示

  • 宇宙航空研究開発機構  研究員   2010年04月 ~ 2013年03月

  • 滋賀大学データサイエンス教育研究推進室  特任講師   2016年01月 ~ 現在

所属学会・委員会 【 表示 / 非表示

  • 地球電磁気学・地球惑星圏学会  

  • 日本気象学会  

  • 日本惑星科学会  

  • American Meteorological Society  

  • 日本リモートセンシング学会  

研究分野(科研費分類) 【 表示 / 非表示

  • 広領域

  • 天文学

  • 気象・海洋物理・陸水学

 

研究テーマ 【 表示 / 非表示

  • 全方位アクションカメラで彦根のお天気を当ててみる

    データサイエンス,統計,機械学習

  • 独立成分分析を用いた火星画像処理

    画像処理,惑星大気,信号処理

  • 火星大気データの時空間スペクトル解析

    惑星大気、信号処理、大気波動

  • 金星観測画像を用いた雲移動ベクトルの導出

    惑星大気、画像処理、パターンマッチング

  • 火星ダストストームの拡大メカニズム研究

    惑星大気、物質輸送、数値シミュレーション

論文 【 表示 / 非表示

  • Segmentation of dust storm areas on Mars images using principal component analysis and neural network

    Gichu, R., Ogohara, K.

     Progress in Earth and Planetary Science  6    2019年02月

    10.1186/s40645-019-0266-1  共著  共同(副担当)

  • Formation of the Y Feature at the Venusian Cloud Top by Planetary-Scale Waves and the Mean Circulation: Analysis of Venus Express VMC Images

    Nara Y., Imamura T., Murakami S., Kouyama T., Ogohara K., Yamada M., Takagi M., Kashimura H., Sato N.

    Journal of Geophysical Research: Planets  Journal of Geophysical Research: Planets    2019年01月

    10.1029/2018JE005779  共著  

    [概要]

    © 2019. American Geophysical Union. All Rights Reserved. The relationship between the planetary-scale ultraviolet contrast known as the Y feature and the wind field at the Venusian cloud top was investigated by using images obtained by Venus Monitoring Camera (VMC) on ESA's Venus Express. Spectral analyses of the ultraviolet reflectivity and the wind field revealed common periodicities of 4–5 Earth days, which are attributed to Kelvin and Rossby waves with a zonal wave number of unity. Combined with the morphological relationship between the dark streaks and the enhancement of poleward flow, we propose a mechanism for the formation of the Y feature: The dark materials are supplied to the cloud top in the equatorial region by a Kelvin wave, subsequently advected poleward by the mean meridional circulation and a Rossby wave, and then stretched by the midlatitude jet to the tilted band structures. A simplified transport model was developed to demonstrate the scenario.

  • Nightside Winds at the Lower Clouds of Venus with Akatsuki/IR2: Longitudinal, Local Time, and Decadal Variations from Comparison with Previous Measurements

    Javier Peralta, Keishiro Muto, Ricardo Hueso, Takeshi Horinouchi, Agustín Sánchez-Lavega , Shin-ya Murakami, Pedro Machado, Eliot F. Young, Yeon Joo Lee , Toru Kouyama, Hideo Sagawa, Kevin McGouldrick, Takehiko Satoh, Takeshi Imamura, Sanjay S. Limaye, Takao M. Sato, Kazunori Ogohara, Masato Nakamura, and David Luz

     The Astrophysical Journal  239 (2)    2018年12月

    10.3847/1538-4365/aae844  共著  共同(副担当)

  • Initiation of a lightning search using the lightning and airglow camera onboard the Venus orbiter Akatsuki

    Takahashi Y., Sato M., Imai M., Lorenz R., Yair Y., Aplin K., Fischer G., Nakamura M., Ishii N., Abe T., Satoh T., Imamura T., Hirose C., Suzuki M., Hashimoto G., Hirata N., Yamazaki A., Sato T., Yamada M., Murakami S., Yamamoto Y., Fukuhara T., Ogohara K., Ando H., Sugiyama K., Kashimura H., Ohtsuki S.

    Earth, Planets and Space  Earth, Planets and Space  70 (1)    2018年05月

    10.1186/s40623-018-0836-2  共著  共同(副担当)

    [概要]

    © 2018, The Author(s). 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.

  • Venus looks different from day to night across wavelengths: morphology from Akatsuki multispectral images

    Limaye S., Watanabe S., Yamazaki A., Yamada M., Satoh T., Sato T., Nakamura M., Taguchi M., Fukuhara T., Imamura T., Kouyama T., Lee Y., Horinouchi T., Peralta J., Iwagami N., Hashimoto G., Takagi S., Ohtsuki S., Murakami S., Yamamoto Y., Ogohara K., Ando H., Sugiyama K., Ishii N., Abe T., Hirose C., Suzuki M., Hirata N., Young E., Ocampo A.

    Earth, Planets and Space  Earth, Planets and Space  70 (1)    2018年02月

    10.1186/s40623-018-0789-5  共著  共同(副担当)

    [概要]

    © 2018, The Author(s). Since insertion into orbit on December 7, 2015, the Akatsuki orbiter has returned global images of Venus from its four imaging cameras at eleven discrete wavelengths from ultraviolet (283 and 365 nm) and near infrared (0.9–2.3 µm), to the thermal infrared (8–12 µm) from a near-equatorial orbit. The Venus Express and Pioneer Venus Orbiter missions have also monitored the planet for long periods but from polar or near-polar orbits. The wavelength coverage and views of the planet also differ for all three missions. In reflected light, the images reveal features seen near the cloud tops (~ 70 km altitude), whereas in the near-infrared images of the nightside, features seen are at mid- to lower cloud levels (~ 48–60 km altitude). The dayside cloud cover imaged at the ultraviolet wavelengths shows morphologies similar to what was observed from Mariner 10, Pioneer Venus, Galileo, Venus Express and MESSENGER. The daytime images at 0.9 and 2.02 µm also reveal some interesting features which bear similarity to the ultraviolet images. The nighttime images at 1.74, 2.26 and 2.32 µm and at 8–12 µm reveal features not seen before and show new details of the nightside including narrow wavy ribbons, curved string-like features, long-scale waves, long dark streaks, isolated bright spots, sharp boundaries and even mesoscale vortices. Some features previously seen such as circum-equatorial belts (CEBs) and occasional areal brightenings at ultraviolet (seen in Venus Express observations) of the cloud cover at ultraviolet wavelengths have not been observed thus far. Evidence for the hemispheric vortex organization of the global circulation can be seen at all wavelengths on the day- and nightsides. Akatsuki images reveal new and puzzling morphology of the complex nightside cloud cover. The cloud morphologies provide some clues to the processes occurring in the atmosphere and are thus, a key diagnostic tool when quantitative dynamical analysis is not feasible due to insufficient information.[Figure not available: see fulltext.].

  • Ultraviolet imager on Venus orbiter Akatsuki and its initial results

    Yamazaki A., Yamada M., Lee Y., Watanabe S., Horinouchi T., Murakami S., Kouyama T., Ogohara K., Imamura T., Sato T., Yamamoto Y., Fukuhara T., Ando H., Sugiyama K., Takagi S., Kashimura H., Ohtsuki S., Hirata N., Hashimoto G., Suzuki M., Hirose C., Ueno M., Satoh T., Abe T., Ishii N., Nakamura M.

    Earth, Planets and Space  Earth, Planets and Space  70 (1)    2018年02月

    10.1186/s40623-017-0772-6  共著  共同(副担当)

    [概要]

    © 2018, The Author(s). The ultraviolet imager (UVI) has been developed for the Akatsuki spacecraft (Venus Climate Orbiter mission). The UVI takes ultraviolet (UV) images of the solar radiation reflected by the Venusian clouds with narrow bandpass filters centered at the 283 and 365 nm wavelengths. There are absorption bands of SO2 and unknown absorbers in these wavelength regions. The UV images provide the spatial distribution of SO2 and the unknown absorber around cloud top altitudes. The images also allow us to understand the cloud top morphologies and haze properties. Nominal sequential images with 2-h intervals are used to understand the dynamics of the Venusian atmosphere by estimating the wind vectors at the cloud top altitude, as well as the mass transportation of UV absorbers. The UVI is equipped with off-axial catadioptric optics, two bandpass filters, a diffuser installed in a filter wheel moving with a step motor, and a high sensitivity charge-coupled device with UV coating. The UVI images have spatial resolutions ranging from 200 m to 86 km at sub-spacecraft points. The UVI has been kept in good condition during the extended interplanetary cruise by carefully designed operations that have maintained its temperature maintenance and avoided solar radiation damage. The images have signal-to-noise ratios of over 100 after onboard desmear processing. [Figure not available: see fulltext.].

  • Automatic detection of typical dust devils from Mars landscape images

    Kazunori Ogohara, Takeru Watanabe, Susumu Okumura, Yuji Hatanaka

     Advances in Space Research  61   1158 ~ 1169  2018年02月

    10.1016/j.asr.2017.11.030  共著  共同(主担当)

  • Automated blood vessel extraction based on high-order local autocorrelation features on retinal images

    Hatanaka Y., Samo K., Ogohara K., Sunayama W., Muramatsu C., Okumura S., Fujita H.

    Lecture Notes in Computational Vision and Biomechanics  Lecture Notes in Computational Vision and Biomechanics  27   803 ~ 810  2018年01月

    10.1007/978-3-319-68195-5_87  共著  

    [概要]

    © 2018, Springer International Publishing AG. Automated blood vessels detection on retinal images is an important process in the development of pathologies analysis systems. This paper describes about an automated blood vessel extraction using high-order local autocorrelation (HLAC) on retinal images. Although HLAC features are shift-invariant, HLAC features are weak to turned image. Therefore, a method was improved by the addition of HLAC features to a polar transformed image. We have proposed a method using HLAC, pixel-based-features and three filters. However, we have not investigated about feature selection and machine learning method. Therefore, this paper discusses about effective features and machine learning method. We tested eight methods by extension of HLAC features, addition of 4 kinds of pixel-based features, difference of preprocessing techniques, and 3 kinds of machine learning methods. Machine learning methods are general artificial neural network (ANN), a network using two ANNs, and Boosting algorithm. As a result, our already proposed method was the best. When the method was tested by using “Digital Retinal Images for Vessel Extraction” (DRIVE) database, the area under the curve (AUC) based on receiver operating characteristics (ROC) analysis was reached to 0.960.

  • Initial products of Akatsuki 1um camera

    Iwagami, N., T. Sakanoi, G. L. Hashimoto, K. Sawai, S. Ohtsuki, S. Takagi, K. Uemizu, M. Ueno, S. Kameda, S. Murakami, M. Nakamura, N. Ishii, T. Abe, T. Satoh, T. Imamura, C. Hirose, M. Suzuki, N. Hirata, A. Yamazaki, T. M. Sato, M. Yamada, Y. Yamamoto, T. Fukuhara, K. Ogohara, H. Ando, K. Sugiyama, H. Kashimura and T. Kouyama

     Earth, Planets and Space  70 (6)    2018年01月

    0.1186/s40623-017-0773-5  共著  共同(副担当)

  • Mean winds at the cloud top of Venus obtained from two-wavelength UV imaging by Akatsuki

    Horinouchi, T., T. Kouyama, Y. J. Lee, S. Murakami, K. Ogohara, M. Takagi, T. Imamura, K. Nakajima, J. Peralta, A. Yamazaki, M. Yamada, S. Watanabe

     Earth, Planets and Space  70 (10)    2018年01月

    共著  共同(副担当)

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総説・解説記事 【 表示 / 非表示

  • 一番星へ行こう!日本の金星探査機の挑戦 その32~データアーカイブ~

    村上真也,山本幸生,はしもとじょーじ,山田学,山崎敦,佐藤隆雄,小郷原一智,高木征弘,Kevin McGouldrick,平田成

     遊星人  26 (3)   92 ~ 96  2017年09月

     共著  共同(副担当)

  • 一番星へ行こう!日本の金星探査機の挑戦その11~科学データ地上処理系~

    山田学、小郷原一智、神山徹、はしもとじょーじ、高木征弘、山崎敦、山本幸生、今村剛

     遊星人    2010年

     共著  共同(副担当)

  • 第一回環境災害研究における流体力学および地球物理学に関するスプリングスクール参加報告

    小郷原一智

     天気  56 (10)   815 ~ 817  2009年

     単著  共同(主担当)

会議での講演 【 表示 / 非表示

  • 「あかつき」で探る金星大気のスーパーローテーション維持機構

    日本地球惑星科学連合2018年大会  2018年05月

  • あかつきIR2昼面画像で探る金星雲頂構造

    日本惑星科学連合2018年大会  2018年05月

  • On the current status of the AKATSUKI data archive

    日本地球惑星科学連合2018年大会  2018年05月

  • 東西、南北風速場の解析から得られた金星雲頂上高度における熱潮汐波構造の定常性について

    日本地球惑星科学連合2018年大会  2018年05月

  • 「あかつき」の紫外二波長撮像により得られた金星雲頂での平均風の構造と変動

    日本地球環癖科学連合2018年大会  2018年05月

  • NIGHTSIDE WINDS AT THE MIDDLE-TO-LOW CLOUDS OF VENUS WITH AKATSUKI/IR2 AND GROUND-BASED OBSERVATIONS

    日本地球惑星科学連合2018年大会  2018年05月

  • Wavenumber-frequency spectra in the Mars atmosphere: the 2 sols waves in low latitudes

    日本惑星科学連合2018年大会  2018年05月

  • Wavenumber-Frequency Spectra of Atmospheric Temperature, Zonal and Meridional Winds in Low Latitudes on Mars

    Sixth international workshop on the Mars atmosphere: Modelling and observations  2017年01月

  • 金星大気中に発見された巨大定在重力波

    2016 年地球 電磁気・地球惑星圏学会講演会  2016年11月

  • 金星周回軌道における「あかつき」初期科学成果の概要

    2016 年地球電磁気・地球惑星圏学会講演会  2016年11月

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受賞学術賞 【 表示 / 非表示

  • the Outstanding Paper Award for Young Scientists

     Numerical simulations of the regional characteristics of dust transport on Mars  国際学会・会議・シンポジウム等の賞  Committee on Space Research  単独  2012年07月

研究シーズ 【 表示 / 非表示

  • 惑星画像を対象とした特徴検出および追跡アルゴリズムの開発と惑星大気研究

 
 

学部講義等担当 【 表示 / 非表示

  • 電子システム工学実験Ⅳ

  • 科学技術英語

  • 線形代数Ⅰ

  • 電子システム工学実験Ⅰ

  • 電子システム工学実験Ⅱ

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学外の社会活動 【 表示 / 非表示