農食環境学群・環境共生学類
教員 小川健太 オガワ ケンタ
メールアドレス:k-ogawa@rakuno.ac.jp
ホームページ:

更新日 :2017/10/25

研究者基本情報

氏名

小川健太
オガワ ケンタ

所属(マスタ)

農食環境学群・環境共生学類, 教員

所属・職名

農食環境学群 環境共生学類
准教授

学位

博士(工学)

所属学協会

日本写真測量学会
日本リモートセンシング学会

研究活動情報

研究キーワード

UAV,
リモートセンシング,
リモートセンシングによる地球観測,

論文

Projection of impacts of climate change on windthrows and evaluation of potential adaptation measures in forest management: A case study from empirical modelling of windthrows in Hokkaido, Japan, by Typhoon Songda (2004), Kohei T. Takano, Kosuke Nakagawa, Masahiro Aiba, Michio Oguro, Junko Morimoto, Yasuto Furukawa, Yoshio Mishima, Kenta Ogawa, Rui Ito and Tetsuya Takemi, Hydrological Research Letters, 10(4), 132 - 138,   2016年12月, 査読有り
内モンゴル通遼地区における農業形態の変遷と地域振興, 小田, 玲実 趙, 明宇 森, 夏節 小川, 健太 發地, 喜久治 小糸, 健太郎 星野, 仏方 金子, 正美, 酪農学園大学紀要, 41, (1) ,   2016年10月, 査読有り
Case studies for observation planning algorithm of a Japanese spaceborne sensor: Hyperspectral Imager Suite (HISUI), Kenta Ogawa, Yukiko Konno, Satoru Yamamoto, Tsuneo Matsunaga, Tetsushi Tachikawa, Mako Komoda, Osamu Kashimura, Shuichi Rokugawa, Proceedings of SPIE - The International Society for Optical Engineering, 10000,   2016年01月

講演・口頭発表等

UAVの環境・農業分野への活用と撮影画像解析の今後, 小川 健太, 一般社団法人日本環境アセスメント協会平成28年度第1回技術セミナー,   2016年09月16日, 招待有り
管理来歴が育成牛放牧草地における養分分布の不均一性におよぼす影響, 三枝俊哉・塚崎顕太郎・加藤祐太・熊谷宇・小川健太・八木隆徳, 日本草地学会石川大会,   2016年03月
釧路湿原におけるエゾシカよる湿地林の生息地利用, 日野 貴文, 吉田 遼人, 五十嵐 守, 佐藤 温貴, 村井 拓成, 立木 靖之, 赤松 里香, 橋本 寛治, 小川 健太, 金子 正美, 吉田 剛司, 日本森林学会第127回大会,   2016年03月
台風被害前後の空中写真から作成したDSMの差分による森林風倒地の推定, 玉利直樹、小川健太、森本淳子、中川考介、三島啓雄, 日本写真測量学会北海道支部第34回学術講演会,   2016年03月, 招待有り
UAV空撮画像を用いたトウモロコシ圃場における植被率の系時変化の推定, 渡邊悠、フラビオ古川、小川健太、吉村暢彦、義平大樹、片山雄太, 日本写真測量学会北海道支部第34回学術講演会,   2016年03月, 招待有り
Case studies for observation planning algorithm of a Japanese spaceborne sensor: Hyperspectral Imager Suite (HISUI), Kenta Ogawa, Yukiko Konno, Satoru Yamamoto, Tsuneo Matsunaga, Tetsushi Tachikawa, Mako Komoda, Osamu Kashimura, Shuichi Rokugawa, SPIE The International Society for Optical Engineering 2016,   2016年01月
Effective observation planning and its simulation of a Japanese spaceborne sensor: Hyperspectral imager suite (HISUI), Kenta Ogawa, Tsuneo Matsunaga, Satoru Yamamoto, Osamu Kashimura, Tetsushi Tachikawa, Satoshi Tsuchida, Jun Tanii, Shuichi Rokugawa, International Geoscience and Remote Sensing Symposium (IGARSS),   2014年01月01日, © 2014 IEEE.Hyperspectral Imager Suite (HISUI) is a Japanese future spaceborne hyperspectral instrument being developed by Ministry of Economy, Trade, and Industry (METI) and will be launched in 2017 or later. In HISUI project, observation strategy is important especially for hyperspectral sensor, and relationship between the limitations of sensor operation and the planned observation scenarios have to be studied. Using observation coverage simulation program and we estimate progress of observation coverage of image with days after launch. We found that HISUI can make 4 times repeated observations for protected area (20 million km2 in the world). And about 70 % of land surface can be observed over 5 years. We also found that the developed rules to avoid cloudy are will improve the area coverage up to 2.4 %.

MISC

釧路湿原におけるエゾシカよる湿地林の生息地利用, 日野 貴文, 吉田 遼人, 五十嵐 守, 佐藤 温貴, 村井 拓成, 立木 靖之, 赤松 里香, 橋本 寛治, 小川 健太, 金子 正美, 吉田 剛司, 日本森林学会第127回大会, doi.org/10.11519/jfsc.127.0_748,   2016年03月
管理来歴が育成牛放牧草地における養分分布の不均一性におよぼす影響, 三枝俊哉・塚崎顕太郎・加藤祐太・熊谷宇・小川健太・八木隆徳, 日本草地学会石川大会,   2016年03月
ドローンの農業利用の可能性と実践例, 小川健太, 酪農ジャーナル,   2016年12月
北海道における森林の風倒予測:2004 年18 号台風の21 世紀末擬似温暖化実験, 髙野(竹中)宏平・饗庭正寛・小黒芳生・中川孝介・森本淳子・古川泰人・三島啓雄・小川健太・伊東瑠衣・竹見哲也, 台風研究会「複合系台風災害のメカニズムに関する研究集会」,   2016年03月
空間計測技術を活用した作物の生育管理, 金子正美、小川健太、鎌形哲稔, 土木技術、特集「土木と食」, 71, (10) 52 - 57,   2016年10月
北海道における森林の風倒評価:2004年台風18号による影響, 中川考介・森本淳子・古川泰人・髙野(竹中)宏平・饗庭正寛・小黒芳生・三島啓雄・小川健太・伊東瑠衣・竹見哲也, 台風研究会「複合系台風災害のメカニズムに関する研究集会」,   2016年03月
農業分野へのマルチプラットフォームセンシングの適用, 鎌形哲稔、前田桂子、福島あゆみ、小川健太, 農業農村工学会誌「水土の知」小特集「圃場モニタリングのためのリモートセンシング技術の最前線-4」, 84,   2016年09月
千鳥播、狭畦、狭畦千鳥栽培が子実用トウモロコシの収量に及ぼす影響, 宋粮・義平大樹・一関悠太・佐藤智宏・小川健太・渡邊悠, 草地学会, 62,   2016年
ドローンを用いたデントコーン圃場における緑被率の高頻度モニタリングの試行, 吉村暢彦、古川フラビオ、渡辺悠、宋粮、大原譽丈、小川健太、義平大樹, 農業農村工学会誌「水土の知」小特集「圃場モニタリングのためのリモートセンシング技術の最前線-7」, 84, (9) 773 - 776,   2016年09月
千鳥播、狭畦栽培が子実用トウモロコシの収量に及ぼす影響―長沼町における機械播種による実規模試験―, 義平大樹・宋粮・土屋恭平・佐藤智宏・小川健太・柳原孝二・照井英樹, 草地学会, 62,   2016年
REDD+推進にむけた森林リモートセンシング技術研修の設計と実施 : 酪農学園大学での研修事例から, 吉村 暢彦, 日野 貴文, 金子 正美, 星野 仏方, 小川 健太, 酪農学園大学紀要. 自然科学編, 40, (1) 35 - 45,   2015年10月, http://ci.nii.ac.jp/naid/110009971001
Observation planning algorithm of a Japanese spaceborne sensor: Hyperspectral Imager Suite (HISUI), Kenta Ogawa, Kayo Nishiwaki, Yukiko Konno, Tsuneo Matsunaga, Satoru Yamamoto, Osamu Kashimura, Tetsushi Tachikawa, Jun Tanii, Proceedings of SPIE - The International Society for Optical Engineering, 9241,   2014年01月01日, 10.1117/12.2066810, https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84922651288&origin=inward, © 2014 SPIE.Hyperspectral Imager Suite (HISUI) is a Japanese future spaceborne hyperspectral instrument being developed by Ministry of Economy, Trade, and Industry (METI) and will be launched in 2017 or later. In HISUI project, observation strategy is important especially for hyperspectral sensor, and relationship between the limitations of sensor operation and the planned observation scenarios have to be studied. We have developed concept of multiple algorithms approach. The concept is to use two (or more) algorithm models (Long Strip Model and Score Downfall Model) to select observing scenes from complex data acquisition requests with satisfactory of sensor constrains. We have tested the algorithm, and found that the performance of two models depends on remaining data acquisitions, i.e. distribution score along with orbit. We conclude that the multiple algorithms approach will be make better collection plans for HISUI comparing with single fixed approach.
香川県直島のシダ植物群生地における林野火災リスク評価, 森本 淳子, 濱本 菜央, 小南 遼, 三島 啓雄, 小川 健太, 日本緑化工学会誌, 40, (1) 120 - 123,   2014年, http://ci.nii.ac.jp/naid/130005099794, 林野火災のリスク評価において,着火と延焼の原因となる地表燃料の定量化は重要である。林床にシダ植物が優占する森林で地表燃料の単位量と総量から林野火災リスクを推定することを研究の目的として,林床にコシダが優占する瀬戸内海地域の二次林で,林冠火災後の森林再生にともなう林床のシダ類と A0 層の乾燥重量の変化を調べた。火災履歴のない森林はどちらの評価方法でも最もリスクが高い結果となったが,火災履歴のある森林では両者の評価結果は異なった。単位量による評価では,経年とともにリスクが増したが,総量による評価では,より最近の火災ほど延焼面積が広く,再生林の連続性が高いためリスクが高くなった。火災リスク評価における景観構造の重要性が示唆された。
Observation planning and its coverage simulation of a Japanese spaceborne sensor: Hyperspectral Imager Suite (HISUI), Kenta Ogawa, Tsuneo Matsunaga, Satoru Yamamoto, Osamu Kashimura, Tetsushi Tachikawa, Satoshi Tsuchida, Jun Tanii, Shuichi Rokugawa, International Geoscience and Remote Sensing Symposium (IGARSS),   2013年12月01日, 10.1109/IGARSS.2013.6723813, https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84894225611&origin=inward, As mentioned above, the simulation program is useful to investigate observation-planning strategy and rules for improving efficiency of observations. © 2013 IEEE.
USage of cloud climate data in operation misson plan simulation for Japanese future hyperspectral and multispectral senor: HISUI, Kenta Ogawa, Tsuneo Matsunaga, Satoru Yamamoto, Osamu Kashimura, Tetsushi Tachikawa, Satoshi Tsuchida, Jun Tanii, Shuichi Rokugawa, International Geoscience and Remote Sensing Symposium (IGARSS),   2012年12月01日, 10.1109/IGARSS.2012.6352335, https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84873125076&origin=inward, Hyperspectral Imager Suite (HISUI) is a Japanese future spaceborne hyperspectral instrument [1][2] being developed by Ministry of Economy, Trade, and Industry (METI) and will be launched in 2015 or later. HISUI's operation strategic study is described in this paper. In HISUI project, Operation Mission Planning (OMP) team will make long term and short term strategy of the observation and sensor operation plan. OMP is important for HISUI especially for hyperspectral sensor, and relationship between the limitations of sensor operation and the planned observation scenarios have to be studied. Major factors of the limitations are the combinations of downlink rate, observation time (15 minutes per orbit) and the swath of the sensor (30 km). The achievements of global mapping or repeated observations of specific site need to be simulated precisely before launch [3]. We have prepared daily global high resolution (30 second in latitude and longitude) climate data for the simulation. © 2012 IEEE.
地図情報を活用した防災情報の収集共有サイクルに関する研究 : 情報収集方法とEMT江別体制構築の検証, 目黒 茂樹, 小川 健太, 鄭 炳表, 消防研究所報告, (112) 1 - 12,図巻頭1p,   2012年03月, http://ci.nii.ac.jp/naid/40019437953
Observation planning strategy of a Japanese spaceborne sensor: Hyperspectral imager suite (HISUI), Kenta Ogawa, Makoto Takenaka, Tsuneo Matsunaga, Satoru Yamamoto, Osamu Kashimura, Tetsushi Tachikawa, Satoshi Tsuchida, Jun Tanii, Shuichi Rokugawa, Proceedings of SPIE - The International Society for Optical Engineering, 8527,   2012年01月01日, 10.1117/12.977316, https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84900305788&origin=inward, Hyperspectral Imager Suite (HISUI) is a Japanese future spaceborne hyperspectral instrument being developed by Ministry of Economy, Trade, and Industry (METI) and will be launched in 2015 or later. HISUIa's operation strategic study is described in this paper. In HISUI project, Operation Mission Planning (OMP) team will make long- and short-term observation strategy of the sensor. OMP is important for HISUI especially for hyperspectral sensor, and relationship between the limitations of sensor operation and the planned observation scenarios have to be studied. Major factors of the limitations are the combinations of downlink rate, observation time (15 minutes per orbit) and the swath of the sensor (30 km). The achievements of global mapping or regional monitoring need to be simulated precisely before launch. We have prepared daily global high resolution (30 second in latitude and longitude) climate data for the simulation. © 2012 SPIE.
Operation plan study for Japanese future hyperspectral mission: HISUI, T. Matsunaga, S. Yamamoto, O. Kashimura, T. Tachikawa, K. Ogawa, A. Iwasaki, S. Tsuchida, N. Ohgi, 34th International Symposium on Remote Sensing of Environment - The GEOSS Era: Towards Operational Environmental Monitoring,   2011年12月01日, https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84879777852&origin=inward, Japanese future spaceborne hyperspectral mission, Hyperspectral Imager Suite (HISUI), will be launched in 2015 or later as one of mission instruments onboard JAXA's Advanced Land Observation Satellite 3 (ALOS-3). HISUI will consist of a hyperspectral imager and a multispectral imager with 30 m and 5 m spatial resolution and 30 km and 90 km swath, respectively. Although observation requests to HISUI from users in various application fields are expected to be so many, the instrument duty time and the allocation of downlink resources of ALOS-3 will limit actual observation of HISUI. Various plans of HISUI operation, which satisfy as much as possible within allocated resources, will be presented.
Simulation of operation of future Japanese spaceborne hyperspectral imager: HISUI, Tsuneo Matsunaga, Satoru Yamamoto, Soushi Kato, Osamu Kashimura, Tetsushi Tachikawa, Kenta Ogawa, Akira Iwasaki, Satoshi Tsuchida, Nagamitsu Ohgi, Shuichi Rokugawa, Proceedings of SPIE - The International Society for Optical Engineering, 8181,   2011年11月25日, 10.1117/12.898376, https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=81755187396&origin=inward, HISUI, a Japanese future spaceborne hyperspectral and multispectral imaging system, is currently being developed by Japanese Ministry of Economy, Trade, and Industry. Because of the narrow swath of the imager as well as the limits on the operation time and data downlink resource allocation, the operation strategy of HISUI should be examined thoroughly to fully utilize HISUI's earth observation capability. A software which simulates HISUI's operation is being developed for the detailed analysis of HISUI's long term operation plans. The simulation results indicate that 1) one-time priority area mapping will be completed within eight months with moderate data downlink allocation, 2) one-time global observation in a year will be possible if the allocated downlink capability is more than 250 GByte per day, 3) the nighttime volcano monitoring will not significantly affect the daytime observation if the cross track pointing only for nighttime observation is not allowed. © 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).
Operation planning for japanese future hyperspectral and multispectral senor: HISUI and usage of cloud climate data, Kenta Ogawa, Tsuneo Matsunaga, Satoru Yamamoto, Osamu Kashimura, Tetsushi Tachikawa, Akira Iwasaki, Satoshi Tsuchida, Jun Tanii, Shuichi Rokugawa, Proceedings of SPIE - The International Society for Optical Engineering, 8176,   2011年11月09日, 10.1117/12.898590, https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=80455168405&origin=inward, Hyperspectral Imager Suite (HISUI) is a Japanese future spaceborne hyperspectral instrument being developed by Ministry of Economy, Trade, and Industry (METI) and will be launched in 2015 or later. HISUI's operation strategic study is described in this paper. In HISUI project, Operation Mission Planning (OMP) team has responsibility to make long term and short term strategy of the observation and sensor operation plan. The OMP is important for HISUI to archive both global mapping and monitoring of specific sites. Major factors of the HISUI operation limitations are downlink rate, observation time (15 minutes per orbit) and the swath of the sensor (30 km). The OMP plans to use detailed climate data generated from MODIS data for observation simulation. The workflow to deal cloud climate data is described in this paper. © 2011 SPIE.
プロジェクト研究の紹介 酪農学園大学農業環境情報サービスセンターの設立と地域連携, 金子 正美, 小川 健太, グリーンテクノ情報, 7, (2) 34 - 38,   2011年10月, http://ci.nii.ac.jp/naid/40019035486
「農業環境情報サービスセンター」の設立構想と役割--環境と共生した循環型農業の実現に向けて (特集 酪農学園大学の新しい農業普及事業), 金子 正美, 小川 健太, 酪農ジャ-ナル, 63, (1) 32 - 35,   2010年01月, http://ci.nii.ac.jp/naid/40016957379
Detecting land cover change at the Jornada Experimental Range, New Mexico with ASTER emissivities, A. N. French, T. J. Schmugge, J. C. Ritchie, A. Hsu, F. Jacob, K. Ogawa, Remote Sensing of Environment, 112,   2008年04月15日, 10.1016/j.rse.2007.08.020, https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=40749148989&origin=inward, Multispectral thermal infrared remote sensing of surface emissivities can detect and monitor long term land vegetation cover changes over arid regions. The technique is based on the link between spectral emissivities within the 8.5-9.5 μm interval and density of sparsely covered terrains. The link exists regardless of plant color, which means that it is often possible to distinguish bare soils from senescent and non-green vegetation. This capability is typically not feasible with vegetation indices. The method is demonstrated and verified using ASTER remote sensing observations between 2001 and 2003 over the Jornada Experimental Range, a semi-arid site in southern New Mexico, USA. A compilation of 27 nearly cloud-free, multispectral thermal infrared scenes revealed spatially coherent patterns of spectral emissivities decreasing at rates on the order of 3% per year with R2 values of ∼ 0.82. These patterns are interpreted as regions of decreased vegetation densities, a view supported by ground-based leaf area index transect data. The multi-year trend revealed by ASTER's 90-m resolution data are independently confirmed by 1-km data from Terra MODIS. Comparable NDVI images do not detect the long-term spatially coherent changes in vegetation. These results show that multispectral thermal infrared data, used in conjunction with visible and near infrared data, could be particularly valuable for monitoring land cover changes. © 2007 Elsevier Inc. All rights reserved.
Estimating broadband emissivity of arid regions and its seasonal variations using thermal infrared remote sensing, Kenta Ogawa, Kenta Ogawa, Thomas Schmugge, Thomas Schmugge, Shuichi Rokugawa, IEEE Transactions on Geoscience and Remote Sensing, 46,   2008年02月01日, 10.1109/TGRS.2007.913213, https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=38349144302&origin=inward, Surface emissivity in the thermal infrared region is an important parameter for determining the surface radiation budget in climate, weather, and hydrological models. This paper focuses on estimating the spatial and temporal variations of the surface emissivities using thermal infrared remotely sensed data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard NASA's Terra satellite. We developed a regression approach to use the ASTER and MODIS data for estimating the broadband emissivity (BBE; 8-13.5 μm). The regressions were calibrated using a library of spectral emissivity data for terrestrial materials. We applied these regressions to ASTER and MODIS data to obtain emissivity maps for several arid regions of the Earth. In the 8-9-μm band for sparsely or nonvegetated desert areas, emissivity values between 0.66 and 0.96 have been observed, which are due to the low emissivity of quartz-rich sands at these wavelengths. As a result, the range of BBE is between 0.86 and 0.96. The seasonal variation over a two-year period and the dependence on land cover/soil type were also investigated. © 2008 IEEE.
Satellite observations of the land surface emissivity in the 8-12 μm window: Effect of soil moisture, Thomas Schmugge, Kenta Ogawa, Patricia De Rosnay, IAHS-AISH Publication,   2007年12月01日, https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=55749086056&origin=inward, Monthly and 8-day composites of thermal infrared (TIR) surface emissivity data from the MODerate resolution Imaging Spectrometer (MODIS) sensor on NASA's Terra satellite were analysed for temporal variations over North Africa. It was found that the emissivity of the 8.55 um band (MODIS band 29) increased by about 0.1 each July/August in the southwestern Sahara (19°N, 3°W). To understand this increase, the emissivity variation was compared with the normalized difference vegetation index (NDVI) also derived from MODIS, with soil moisture estimates from the Advanced Microwave Scanning Radiometer (AMSR-E) microwave sensor on NASA's Aqua satellite and with ground measures of soil moisture. No correspondence was found with NDVI in this area. However, the TIR emissivity increase was found to be qualitatively correlated with an increase in the AMSR derived soil moisture. This increase in TIR emissivity with soil moisture is in agreement with the laboratory measurements. Copyright © 2007 IAHS Press.
Vegetation change detection using thermal band emissivities over Jornada, New Mexico, USA, Andrew N. French, Thomas J. Schmugge, Jerry C. Ritchie, Ann Hsu, Frederic Jacob, Kenta Ogawa, IAHS-AISH Publication,   2007年12月01日, https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=55749115454&origin=inward, Detecting land cover change over semi-arid rangeland is important for monitoring vegetation responses to drought, population expansion, and changing agricultural practices. Such change can be detected using vegetation indices, but these do not represent non-green vegetation and are dominated by seasonal changes. An alternative is to observe spatial changes in thermal emissivities, a measure that responds to soil surface composition and vegetation cover. Because soil emissivities are usually stable, temporal emissivity changes could be due to vegetation cover changes. Using ASTER thermal infrared observations, the technique is applied to observations over the Jornada Experimental Range in New Mexico between 2001 and 2003. The study showed spatially coherent regions where broadband emissivities decreased as much as 3%. These coherent regions may correspond to decreased vegetation densities, suggesting that the technique could be helpful for monitoring rangeland cover. Copyright © 2007 IAHS Press.
Validation of emissivity estimates from ASTER and MODIS data, Thomas Schmugge, Kenta Ogawa, International Geoscience and Remote Sensing Symposium (IGARSS),   2006年12月01日, 10.1109/IGARSS.2006.71, https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=34948829039&origin=inward, Two distinctly different approaches are used to extract emissivity information from ASTER and MODIS data. ASTER uses an intuitive empirical relationship between the range of emissivities in the 5 ASTER bands and their minimum value. With its greater swath MODIS is able to uses the day / night pair of observations to obtain the emissivities. The combination of the two approaches should provide robust estimation of the land surface emissivity.
Estimating thermal infrared broadband emissivity of arid region using remote sensing, Kenta Ogawa, Kenta Ogawa, Thomas Schmugge, Shuichi Rokugawa, Proceedings of SPIE - The International Society for Optical Engineering, 5655,   2005年06月20日, 10.1117/12.583186, https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=20344374752&origin=inward, Surface emissivity in the thermal infrared region is an important parameter for the studies of energy budget and surface energy balance. This paper focuses on estimating broadband emissivity using two sensors on NASA's Earth Observing System (EOS) Terra satellite, Advanced Spaceborne Thermal Emission and reflection Radiometer (ASTER) and MODerate resolution Imaging Spectrometer (MODIS). We developed a regression approach to generate infrared broadband emissivity maps from ASTER or MODIS data. The regressions are to relate the broadband emissivity to the emissivities for the ASTER or MODIS channels. The both regressions were calibrated using libraries of spectral emissivities. We applied this approach for ASTER and MODIS data acquired over the North Africa and Australia. The range of the broadband emissivity was found to be between 0.86 and 0.96 for the desert area. The root mean difference between the emissivities from these two sensors is smaller than 0.015. Such emissivity map could be used as an input of climate model and could contribute for improving the simulated surface and air temperature up to 1.1 and 0.8°C respectively. The method can be applied to any arid regions of the world.
Comparison of land surface emissivity and radiometric temperature derived from MODIS and ASTER sensors, Frédéric Jacob, Frédéric Jacob, François Petitcolin, Thomas Schmugge, Éric Vermote, Andrew French, Kenta Ogawa, Remote Sensing of Environment, 90,   2004年03月30日, 10.1016/j.rse.2003.11.015, https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=1542349980&origin=inward, This study compared surface emissivity and radiometric temperature retrievals derived from data collected with the MODerate resolution Imaging Spectroradiometer (MODIS) and Advanced Spaceborne Thermal Emission Reflection Radiometer (ASTER) sensors, onboard the NASA's Earth Observation System (EOS)-TERRA satellite. Two study sites were selected: a semi-arid area located in northern Chihuahuan desert, USA, and a Savannah landscape located in central Africa. Atmospheric corrections were performed using the MODTRAN 4 atmospheric radiative transfer code along with atmospheric profiles generated by the National Center for Environmental Predictions (NCEP). Atmospheric radiative properties were derived from MODTRAN 4 calculations according to the sensor swaths, which yielded different strategies from one sensor to the other. The MODIS estimates were then computed using a designed Temperature-Independent Spectral Indices of Emissivity (TISIE) method. The ASTER estimates were derived using the Temperature Emissivity Separation (TES) algorithm. The MODIS and ASTER radiometric temperature retrievals were in good agreement when the atmospheric corrections were similar, with differences lower than 0.9 K. The emissivity estimates were compared for MODIS/ASTER matching bands at 8.5 and 11 μm. It was shown that the retrievals agreed well, with RMSD ranging from 0.005 to 0.015, and biases ranging from -0.01 to 0.005. At 8.5 μm, the ranges of emissivities from both sensors were very similar. At 11 μm, however, the ranges of MODIS values were broader than those of the ASTER estimates. The larger MODIS values were ascribed to the gray body problem of the TES algorithm, whereas the lower MODIS values were not consistent with field references. Finally, we assessed the combined effects of spatial variability and sensor resolution. It was shown that for the study areas we considered, these effects were not critical. © 2004 Elsevier Inc. All rights reserved.
A sensitivity study of climate and energy balance simulations with use of satellite-derived emissivity data over Northern Africa and the Arabian Peninsula, L. Zhou, R. E. Dickinson, Y. Tian, M. Jin, K. Ogawa, H. Yu, T. Schmugge, Journal of Geophysical Research D: Atmospheres, 108,   2003年12月27日, https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=1642317905&origin=inward, This paper analyzes the sensitivity of simulated climate and energy balance to changes in soil emissivity over Northern Africa and the Arabian Peninsula and considers how this information may be used to improve emissivity parameterizations in climate models. Analysis of satellite observations suggests that the soil emissivity in current models is too high over this region. Sensitivity tests based on the recently developed Community Land Model indicate that this bias could produce significant errors in the model simulated ground and air temperature, net and upward longwave radiation, and sensible heat flux. There is a linear relationship between changes in emissivity and changes in these variables. Statistical results show that, on average for the study region, a decrease of soil emissivity by 0.1 will increase ground and air temperature by about 1.1°C and 0.8°C and decrease net and upward longwave radiation by about 6.6 Wm-2 and 8.1 Wm-2, respectively, at the ground surface. The decreased net longwave radiation (less emission) is mainly balanced by an increase of sensible heat flux of about 5.9 Wm-2. These relations vary seasonally and diurnally. The temperature increases are slightly higher in winter than in summer and twice as large during nighttime as during daytime, while the sensible heat flux and longwave radiation show more change in summer/daytime than in winter/ nighttime. Our experimental results are consistent with our theoretical energy balance analyses. When a more realistic emissivity value is used, the model cold bias over the Sahara in comparison with land surface air temperature observations could be partially reduced. These results indicate that the simple representations of the land surface emissivity in climate models, especially for bare soil, need improvements based on satellite and in situ observations. Copyright 2003 by the American Geophysical Union.
Mapping Land Surface Window (8-12 μm) Emissivity from ASTER Thermal Data, Kenta Ogawa, Thomas Schmugge, Frederic Jacob, Andrew French, International Geoscience and Remote Sensing Symposium (IGARSS), 5,   2003年11月24日, https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=0242457461&origin=inward, Land surface window (8-12 μm) emissivity is an important parameter for estimating the longwave radiation budget in the study of earth-atmosphere system. This paper focuses on estimation and validation of the window emissivity using the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data. Using this sensor, it is possible to estimate surface spectral emissivity for five channels in thermal infrared region. An example is presented for a desert region in North Africa. In this paper, a multiple regression was used to relate the five ASTER emissivities to the window emissivity. This regression was developed using laboratory spectral measurement data. We validated this approach using a field radiometer that has a window channel and five spectral channels similar to ASTER'S wavelengths. The predicted window emissivities agreed within 0.01 RMSE of measured window emissivity. We applied this regression to emissivities extracted from ASTER data acquired in 2001 and 2002 over a 400 km by 1200 km area in the Sahara Desert. The derived emissivity map showed that the value widely ranges between 0.82 and 0.96 in desert region. These results show that ASTER data is useful for mapping the spatial variations of surface window emissivity over large area in the deserts of the world.
Validation of Emissivity Estimates from ASTER Data, Thomas Schmugge, Kenta Ogawa, Kenta Ogawa, Frederic Jacob, Andrew French, Ann Hsu, Jerry Ritchie, International Geoscience and Remote Sensing Symposium (IGARSS), 3,   2003年11月24日, https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=0242710899&origin=inward, The multispectral thermal infrared data obtained from the Advanced Spaceborne Thermal Emission and Reflection (ASTER) radiometer have been shown to be of good quality. ASTER is on NASA's Terra satellite. It has 5 bands in the 8 to 12 micrometer waveband with 90 m spatial resolution, when the data are combined with the Temperature Emissivity Separation (TES) algorithm the surface emissivity over this wavelength region can be determined. This paper will present some quantitative emissivity results obtained over test sites in southern New Mexico, USA; the Jornada Experimental Range and the White Sands National Monument which are compared with ground measurements. The Jornada site is typical of a desert grassland where the main vegetation components are grass and shrubs with a large fraction of exposed soil. While the White Sands site is mainly dunes of gypsum sand which provides relatively good homogenous emissivity target. More than a dozen ASTER scenes over these New Mexico test sites have been acquired since the launch of Terra in December 1999. There were simultaneous field campaigns in May of 2000, 2001 and 2002 and September/ October 2001 and 2002. Also, simultaneous MASTER (MODIS-ASTER airborne simulator) coverage was obtained for several of the dates. In spite of the 90 m resolution, the results appear to be in good quantitative agreement with laboratory measurements of the emissivity for the quartz rich soils of the Jornada with values < 0.85 for the 8 - 9 micrometer channels. For the longest wavelength channels little spatial variation of the emissivity was observed with values of 0.96 +/- 0.005 over large areas. Emissivity values derived from several ASTER scenes for the gypsum at White Sands were in good agreement with field measurements and values calculated from the lab spectra for gypsum and with each other. Gypsum has a strong emissivity minimum centered on the ASTER 8.63 micrometer band, and the satellite results for this band agree within 0.01 of the value calculated from the laboratory spectra.
Relations between albedos and emissivities from MODIS and ASTER data over North African Desert, L. Zhou, R. E. Dickinson, K. Ogawa, Y. Tian, M. Jin, T. Schmugge, E. Tsvetsinskaya, Geophysical Research Letters, 30,   2003年10月15日, https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=1242345154&origin=inward, This paper analyzes relations among MODIS surface albedos, ASTER broadband (3-14 μm) emissivities, and a soil taxonomy map over the arid areas of Algeria, Libya, and Tunisia in North Africa at 30 second (about 1 km) and 2 minute (about 4 km) spatial resolutions. The MODIS albedo data are from 7 spectral bands and 3 broadbands during dust-free seasons and the emissivity data are derived from a linear combination of the waveband emissivities of the ASTER five thermal infrared channels. Both albedo and emissivity data in the study region show similar considerable spatial variability, larger than assumed by most climate models, and such variability is related to the surface types (sands, rock, and soil orders). Emissivity over bare soils exhibits statistically significant correlations with albedos at both broadbands and most of spectral bands and decreases linearly with albedos. Albedo and emissivity are more strongly correlated with each other than either is to the surface types, apparently because of their higher resolution either spatially or in surface mineralogy. This paper provides guidance for the possible inclusion of such correlation to specify albedo and emissivity in climate models. © 2003 by the American Geophysical Union.
Estimation of land surface window (8-12 μm) emissivity from multi-spectral thermal infrared remote sensing - A case study in a part of Sahara Desert, Kenta Ogawa, Thomas Schmugge, Frederic Jacob, Andrew French, Geophysical Research Letters, 30,   2003年01月15日, https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=0038605124&origin=inward, Land surface window emissivity is an important parameter for estimating the longwave radiative budget. This study focuses on estimating the window (8-12 μm) emissivity from the waveband emissivities of the five thermal infrared channels of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). ASTER data along with the Temperature-Emissivity Separation (TES) algorithm allows us to estimate surface channel emissivities with 90 m spatial resolution globally. Multiple regression was used to relate window emissivity to the five ASTER emissivities. This regression was developed using spectral libraries. Its residual error was less than 0.005 (RMSE) for values ranging between 0.81 and 1.00. We applied this regression to ASTER emissivities extracted from data acquired in 2001 and 2002 over a 240 x 1200 km area in a desert of North Africa. A comparison against a classification based emissivity map showed significant differences ranging between -0.08 and +0.06.
Two surface temperature retrieval methods compared over agricultural lands, Andrew N. French, Thomas J. Schmugge, Frederic Jacob, Kenta Ogawa, Proceedings of SPIE - The International Society for Optical Engineering, 4879,   2002年12月01日, 10.1117/12.462452, https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=0038193899&origin=inward, Accurate, spatially distributed surface temperatures are required for modeling evapotranspiration (ET) over agricultural fields under wide ranging conditions, including stressed and unstressed vegetation. Modeling approaches that use surface temperature observations, however, have the burden of estimating surface emissivities. Emissivity estimation, the subject of much recent research, is facilitated by observations in multiple thermal infrared bands. But it is nevertheless a difficult task. Using observations from multiband thermal sensors, ASTER and MASTER, estimated surface emissivities and temperatures are retrieved in two different ways: the temperature emissivity separation approach (TES). and the normalized emissivity approach (NEM). Both rely upon empirical relationships, but the assumed relationships are different. TES relies upon a relationship between the minimum spectral emissivity and the range of observed emissivities. NEM relies upon an assumption that at least one thermal band has a predetermined emissivity (close to 1.0). Experiments comparing TES and NEM were performed using simulated observations from spectral library data, and with actual data from two different landscapes- one in central Oklahoma. USA, and another in southern New Mexico, USA. The simulation results suggest that TES's empirical relationship is more realistic than NEM's assumed maximum emissivity, and therefore TES temperature estimates are more accurate than NEM estimates. But when using remote sensing data. TES estimates of maximum emissivities are lower than expected, thus causing overestimated temperatures. Work in progress will determine the significance of this overestimation by comparing ground level measurements against the remote sensing observations.
ASTER thermal infrared observations over New Mexico, Thomas Schmugge, Andrew French, Frederic Jacob, Kenta Ogawa, Jerry Ritchie, Mark Chopping, Albert Rango, Proceedings of SPIE - The International Society for Optical Engineering, 4879,   2002年12月01日, 10.1117/12.462464, https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=0037856128&origin=inward, The Advanced Spaceborne Thermal Emission Reflectance Radiometer (ASTER) has acquired more than a dozen clear sky scenes over the Jornada Experimental Range in New Mexico since the launch of NASA's Terra satellite in December, 1999. To support the ASTER overpasses there were simultaneous field campaigns for the 5/09/00, 5/12/01. 9/17/01 and 5/15/02 scenes. Also, data from an airborne simulator. MASTER, were obtained for the 5/12/01 and 5/15/02 scenes to provide high resolution (3 m) data roughly coincident with ASTER. The Jornada Experimental Range is a long term ecological reserve (LTER) site located at the northern end of the Chihuahuan desert. The site is typical of a desert grassland where the main vegetation components are grass and shrubs. The White Sands National Monument is also within several of the scenes. ASTER has 5 channels in the 8 to 12 micrometer wave band with 90 meter resolution and thus is able to provide information on both the surface temperature and emissivity. The Temperature Emissivity Separation (TES) algorithm was used to extract emissivity values from the ASTER data for 5 sites on the Jornada and for the gypsum sand at White Sands. The results are in good agreement with values calculated from the lab spectra for gypsum and with each other. The results for sites in the Jornada show reasonable agreement with the lab results when the mixed pixel problem is taken into account. These results indicate ASTER and TES are working very well. The surface brightness temperatures from ASTER were in reasonable agreement with measurements made on the ground during the field campaigns.
アメリカ合衆国農務省における熱赤外リモートセンシングと地表面熱収支に関する研究, 小川 健太, 水文・水資源学会誌, 15,   2002年07月05日, http://ci.nii.ac.jp/naid/10008835525
Estimation of broadband emissivity from satellite multi-channel thermal infrared data using spectral libraries, Kenta Ogawa, Thomas Schmugge, Frederic Jacob, Andrew French, International Geoscience and Remote Sensing Symposium (IGARSS), 6,   2002年01月01日, https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=0036402216&origin=inward, Surface broadband thermal infrared emissivity is an important parameter for estimating the longwave surface energy balance. This study focuses on estimating the broadband emissivity from the emissivities of the five channels on the Advanced Spaceborne Thermal Emission and Reflection Radiometer/Thermal Infrared Radiometer (ASTER/TIR). ASTER is a sensor onboard the Earth Observing System (EOS) Terra satellite launched in 1999, and has five channels in the thermal infrared region (8-12 μm). Using this sensor, it is possible to estimate surface spectral emissivity for each channel at a spatial resolution of 90 m. Broadband emissivities (3-14 μm) were calculated using two spectral libraries, John Hopkins University Spectral Library (JHU Library) and MODIS UCSB (University of California, Santa Barbara) Emissivity Library (UCSB Library). They ranged from 0.89 to 0.99 for natural surfaces, such as, rocks, soils, vegetation, water, ice, and snow. Then, we assumed that the broadband emissivity can be expressed as a linear combination emissivities for the five ASTER/TIR channels. The linear regression was calibrated using JHU Library and validated with the UCSB Library. The absolute error on the estimated broadband emissivity was less than 0.01 for 93% of all samples and RMSE was 0.0051 over an emissivity range from 0.91 to 0.99 in validation. Finally, this calibrated regression was applied to emissivities computed from the data acquired with ASTER/TIR over the Jornada Experimental Range in New Mexico to produce a map of broadband emissivity for this area.
Estimation of broadband land surface emissivity from multi-spectral thermal infrared remote sensing, Kenta Ogawa, Thomas Schmugge, Frédéric Jacob, Andrew French, Agronomie, 22,   2002年01月01日, https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=0036033393&origin=inward
リモートセンシングの普及に関する課題と将来, 小川 健太, 日本リモートセンシング学会誌 = Journal of the Remote Sensing Society of Japan, 21, (1) 110 - 111,   2001年03月31日, http://ci.nii.ac.jp/naid/10007236227
熱赤外多バンドリモートセンシングデータを用いた岩石表面のデザート・バーニッシュの厚さの評価, 小川 健太, 六川 修一, 松永 恒雄, 二宮 芳樹, 日本リモートセンシング学会誌 = Journal of the Remote Sensing Society of Japan, 19, (1) 45 - 58,   1999年03月31日, http://ci.nii.ac.jp/naid/10003791093
A comparison of thermal infrared emissivity spectra measured in situ, in the laboratory, and derived from thermal infrared multispectral scanner (TIMS) data in Cuprite, Nevada, U.S.A, Y. Ninomiya, T. Matsunaga, Y. Yamaguchi, Y. Yamaguchi, K. Ogawa, K. Ogawa, S. Rokugawa, K. Uchida, H. Muraoka, M. Kaku, M. Kaku, International Journal of Remote Sensing, 18,   1997年01月01日, 10.1080/014311697218287, https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=0031147842&origin=inward, In order to obtain ground truth data for multispectral thermal infrared sensors such as TIMS and ASTER, in situ spectral emissivity measurements were made during field surveys. These spectral emissivity measurements and laboratory spectral reflectance measurements of field samples were compared to emissivity spectra extracted from TIMS data at the surveyed points. The results indicate that emissivity spectra derived from the TIMS data agree well in shape with the spectra measured in situ or in the laboratory. © 1997, Taylor & Francis Group, LLC. All rights reserved.
熱赤外リモートセンシングデータを用いた岩石の風化作用の評価の試み, 小川 健太, 六川 修一, 松永 恒雄, 二宮 芳樹, 学術講演会論文集 = Proceedings of the ... Japanese Conference on Remote Sensing, 19,   1995年11月01日, http://ci.nii.ac.jp/naid/10003791738
熱赤外分光特性を用いた岩石の風化作用の評価について, 小川 健太, 六川 修一, 松永 恒雄, 二宮 芳樹, 学術講演会論文集 = Proceedings of the ... Japanese Conference on Remote Sensing, 18,   1995年05月01日, http://ci.nii.ac.jp/naid/10003791564
環境放射を低減した熱赤外分光放射率の室内測定, 松永 恒雄, 二宮 芳樹, 吉川 秀樹, 山口 靖, 小川 健太, 学術講演会論文集 = Proceedings of the ... Japanese Conference on Remote Sensing, 18,   1995年05月01日, http://ci.nii.ac.jp/naid/10003791560
二温度黒体で較正する分光放射率測定法とその誤差要因, 二宮 芳樹, 松永 恒雄, 小川 健太, 笹野 英生, 六川 修一, 学術講演会論文集 = Proceedings of the ... Japanese Conference on Remote Sensing, 18,   1995年05月01日, http://ci.nii.ac.jp/naid/10003791556

特許

画像情報処理システム, 石丸 伸裕, 岩村 一昭, 田中 紀夫, 室 啓朗, 小川 健太, 特願2004-090901, 特開2005-276004
画像情報処理システム, 石丸 伸裕, 岩村 一昭, 田中 紀夫, 室 啓朗, 小川 健太, 特願2004-090901, 特開2005-276004, 特許第4251101号
目標物抽出・表示方法、及び、目標物抽出・表示装置, 石丸 伸裕, 小川 祐紀雄, 小川 健太, 岩村 一昭, 野本 安栄, 特願2000-126231, 特開2001-307106
目標物検出方法及び目標物検出装置, 石丸 伸裕, 小川 祐紀雄, 小川 健太, 岩村 一昭, 野本 安栄, 特願2000-126231, 特開2001-307106, 特許第3978979号
画像処理システム, 小川 健太, 田中 紀夫, 野本 安栄, 特願平9-314826, 特開平11-149548

競争的資金

環境省, 環境研究総合推進費, フィールド調査とロボット・センサ・通信技術をシームレスに連結する水域生態系モニタリングシステムの開発, 小川 健太
総務省, 消防防災科学技術研究推進制度, 大規模林野火災におけるドローンとリアルタイムGIS活用による対応の効率化と安全性向上, 金子 正美
農水省, 革新的技術開発・緊急展開事業(先導プロジェクト)ICT,ロボット技術等を活用した牧草生産の省力的技術体系の確立, 無人航空機(UAV)とロボットトラクタを活用した省力的牧草生産技術体系の確立, 小川 健太
公益財団法人北海道農業公社, 受託研究, GIS、リモートセンシング(以下R/S)、ICTを用いた農用地開発整備業務の効率化手法の開発, 金子 正美
経済産業省, 次世代地球観測衛星利用基盤技術の研究開発, ハイパースペクトルセンサ・データの高度利用等に係る研究開発(再委託), 小川 健太

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