Mr. Masahiro Kojima Profile

Masahiro Kojima

at Japan Aerospace Exploration Agency

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Author

Publications (10)

Proceedings Article | 7 October 2014 Paper

Orbital checkout result of the dual-frequency precipitation radar on the global precipitation measurement core spacecraft

K. Furukawa, M. Kojima, T. Miura, Y. Hyakusoku, H. Kai, T. Ishikiri, T. Iguchi, H. Hanado, K. Nakagawa, M. Okumura

Proceedings Volume 9241, 92410S (2014) https://doi.org/10.1117/12.2067114

KEYWORDS: Radar, Space operations, Satellites, Calibration, Microwave radiation, Observatories, Antennas, Radiometry, Aerospace engineering, Communication and information technologies

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The Dual-frequency Precipitation Radar (DPR) on the Global Precipitation Measurement (GPM) core satellite was developed by Japan Aerospace Exploration Agency (JAXA) and National Institute of Information and Communications Technology (NICT). The GPM is a follow-on mission of the Tropical Rainfall Measuring Mission (TRMM). The objectives of the GPM mission are to observe global precipitation more frequently and accurately than TRMM. The frequent precipitation measurement about every three hours will be achieved by some constellation satellites with microwave radiometers (MWRs) or microwave sounders (MWSs), which will be developed by various countries. The accurate measurement of precipitation in mid-high latitudes will be achieved by the DPR. The GPM core satellite is a joint product of National Aeronautics and Space Administration (NASA), JAXA and NICT. NASA developed the satellite bus and the GPM Microwave Imager (GMI), and JAXA and NICT developed the DPR. JAXA and NICT developed the DPR through procurement. The contract for DPR was awarded to NEC TOSHIBA Space Systems, Ltd. The configuration of precipitation measurement using active radar and a passive radiometer is similar to TRMM. The major difference is that DPR is used in GPM instead of the precipitation radar (PR) in TRMM. The inclination of the core satellite is 65 degrees, and the flight altitude is about 407 km. The non-sun-synchronous circular orbit is necessary for measuring the diurnal change of rainfall similarly to TRMM. The DPR consists of two radars, which are Ku-band (13.6 GHz) precipitation radar (KuPR) and Ka-band (35.5 GHz) precipitation radar (KaPR). Both KuPR and KaPR have almost the same design as TRMM PR. The DPR system design and performance were verified through the development test and the proto flight test. DPR had handed over to NASA and integration of the DPR to the GPM core spacecraft had completed in May 2012. GPM core spacecraft satellite system test had completed in November 2013. The result of the satellite system test concerning to the DPR satisfied system requirements. GPM core observatory was shipped to Tanegashima Space Center, JAPAN and Launch Site Operations had started on November 2013 and GPM core observatory was launched at 18:37:00 (UT) on February 27, 2014 successfully. DPR orbital check out was completed in May 2014. The orbital check out and the initial calibration and validation operation result of DPR is reported.

Proceedings Article | 9 November 2012 Paper

Dual-frequency precipitation radar (DPR) development on the global precipitation measurement (GPM) core observatory

M. Kojima, T. Miura, K. Furukawa, Y. Hyakusoku, T. Ishikiri, H. Kai, T. Iguchi, H. Hanado, K. Nakagawa

Proceedings Volume 8528, 85281A (2012) https://doi.org/10.1117/12.976823

KEYWORDS: Observatories, Radar, Calibration, Satellites, Pulmonary function tests, Microwave radiation, Space operations, Radiometry, Antennas, Aerospace engineering

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Proceedings Article | 25 October 2012 Paper

Status of proto-flight model of the dual-frequency precipitation radar for the global precipitation measurement

T. Miura, M. Kojima, K. Furukawa, Y. Hyakusoku, T. Ishikiri, H. Kai, T. Iguchi, H. Hanado, K. Nakagawa

Proceedings Volume 8533, 853309 (2012) https://doi.org/10.1117/12.974782

KEYWORDS: Radar, Space operations, Satellites, Microwave radiation, Radiometry, Meteorology, Aerospace engineering, Communication and information technologies, Ku band, Ka band

Read Abstract +

The Dual-frequency Precipitation Radar (DPR) on the Global Precipitation Measurement (GPM) core spacecraft is being developed by Japan Aerospace Exploration Agency (JAXA) and National Institute of Information and Communications Technology (NICT). The GPM is a follow-on mission of the Tropical Rainfall Measuring Mission (TRMM). The objectives of the GPM mission are to observe global precipitation more frequently and accurately than TRMM. The frequent precipitation measurement about every three hours will be achieved by some constellation satellites with microwave radiometers (MWRs) or microwave sounders (MWSs), which will be developed by various countries. The accurate measurement of precipitation in mid-high latitudes will be achieved by the DPR. The GPM core satellite is a joint product of National Aeronautics and Space Administration (NASA), JAXA and NICT. NASA is developing the satellite bus and the GPM microwave radiometer (GMI), and JAXA and NICT are developing the DPR. JAXA and NICT are developing the DPR through procurement. The contractor for DPR is NEC TOSHIBA Space Systems, Ltd. The configuration of precipitation measurement using an active radar and a passive radiometer is similar to TRMM. The major difference is that DPR is used in GPM instead of the precipitation radar (PR) in TRMM. The inclination of the core spacecraft is 65 degrees, and the flight altitude is about 407 km. The non-sun-synchronous circular orbit is necessary for measuring the diurnal change of rainfall similarly to TRMM. The DPR consists of two radars, which are Ku-band (13.6 GHz) precipitation radar (KuPR) and Ka-band (35.55 GHz) precipitation radar (KaPR). According to the different detectable dynamic ranges, The KaPR will detect snow and light rain, and the KuPR will detect heavy rain. In an effective dynamic range in both KuPR and KaPR, drop size distribution information and more accurate rainfall estimates will be provided by a dual-frequency algorithm. The proto-flight test for DPR have finished in February 2012 and DPR integration on GPM core spacecraft was successfully completed in May 2012. The status of proto-flight model of DPR will be presented.

Proceedings Article | 3 October 2011 Paper

Status of proto-flight test of the dual-frequency precipitation radar for the global precipitation measurement

T. Miura, M. Kojima, K. Furukawa, Y. Hyakusoku, T. Iguchi, H. Hanado, K. Nakagawa, M. Okumura

Proceedings Volume 8176, 81760P (2011) https://doi.org/10.1117/12.898083

KEYWORDS: Radar, Satellites, Microwave radiation, Radiometry, Communication and information technologies, Electromagnetism, Neodymium, Inspection, Aerospace engineering, Meteorology

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Proceedings Article | 13 October 2010 Paper

Status of development of the GPM Dual-frequency Precipitation Radar (DPR), algorithm development, and ground validation activities

Misako Kachi, Takeshi Miura, Riko Oki, Shuji Shimizu, Takuji Kubota, Naofumi Yoshida, Yasutoshi Hyakusoku, Kinji Furukawa, Masahiro Kojima, Toshio Iguchi, Kenji Nakamura

Proceedings Volume 7826, 78260A (2010) https://doi.org/10.1117/12.865552

KEYWORDS: Algorithm development, Radar, Satellites, Microwave radiation, Meteorology, Calibration, Ka band, Detection and tracking algorithms, Signal attenuation, Standards development

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Proceedings Article | 17 October 2007 Paper

Development of the DPR algorithms and products for GPM

Shuji Shimizu, Riko Oki, Misako Kachi, Hiroshi Hanado, Masahiro Kojima, Toshio Iguchi, Kenji Nakamura

Proceedings Volume 6744, 67440I (2007) https://doi.org/10.1117/12.739032

KEYWORDS: Satellites, Radar, Floods, Microwave radiation, Sensors, Algorithm development, Meteorology, Radiometry, Earth observing sensors, Climatology

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Proceedings Article | 30 November 2006 Paper

Global precipitation measurement (GPM) mission and its application for flood monitoring

Misako Kachi, Riko Oki, Shuji Shimizu, Masahiro Kojima

Proceedings Volume 6407, 64070A (2006) https://doi.org/10.1117/12.694043

KEYWORDS: Satellites, Floods, Microwave radiation, Radar, Radiometry, Climatology, Earth observing sensors, Sensors, Clouds, Eye

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Proceedings Article | 3 October 2006 Paper

Development of spaceborne dual frequency precipitation radar for the global precipitation measurement mission

Shuji Shimizu, Riko Oki, Masahiro Kojima, Toshio Iguchi, Kenji Nakamura

Proceedings Volume 6361, 63610O (2006) https://doi.org/10.1117/12.694963

KEYWORDS: Satellites, Radar, Meteorology, Antennas, Radiometry, Microwave radiation, Algorithm development, Control systems, Climatology, Waveguides

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Proceedings Article | 21 October 2005 Paper

Global precipitation measurement (GPM) mission and dual-frequency precipitation radar (DPR)

Kenji Nakamura, Riko Oki, Toshio Iguchi, Masahiro Kojima

Proceedings Volume 5978, 597806 (2005) https://doi.org/10.1117/12.629624

KEYWORDS: Satellites, Radar, Radiometry, Meteorology, Microwave radiation, Algorithm development, Climatology, Antennas, Solids, Systems modeling

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Proceedings Article | 27 January 1997 Paper

Development results of the precipitation radar on TRMM

Masahiro Kojima, Toneo Kawanishi, Hiroshi Kuroiwa, Koki Oikawa, Toshiaki Kozu

Proceedings Volume 2957, (1997) https://doi.org/10.1117/12.265433

KEYWORDS: Calibration, Antennas, Radar, Databases, Space operations, Amplifiers, Temperature metrology, Observatories, Attenuators, Data communications

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Showing 5 of 10 publications

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