[A-CG06_29AM1] Satellite Earth Environment Observation

[ACG06-07] 全球降水観測計画/二周波降水レーダの軌道上初期機能確認状況

*小嶋 正弘¹、古川 欣司¹、三浦 健史¹、百束 泰俊¹、改井 洋樹¹、石切 孝之¹、井口 俊夫²、花土 弘²、中川 勝広²、奥村 実³ (1.宇宙航空研究開発機構、2.情報通信研究機構、3.NEC東芝スペースシステム株式会社)

キーワード：全球降水観測計画, 二周波数降水レーダ

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 radiometer (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 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 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). The objectives of the DPR are (1) to provide three-dimensional precipitation structure including snowfall over both ocean and land, (2) to improve the sensitivity and accuracy of precipitation measurement, (3) to calibrate the estimated precipitation amount by MWRs and MWSs on the constellation satellites.The DPR consists of Ku-band (13.6 GHz) precipitation radar (KuPR) and Ka-band (35.5 GHz) precipitation radar (KaPR). The KuPR unit will measure 2.6m X 2.4m X 0.7m in size. The KaPR unit will measure 1.3m X 1.5m X 0.8m in size. 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 has handed over to NASA and integration of the DPR to the GPM core spacecraft have completed in May 2012. GPM core spacecraft satellite system test has completed in November 2013. The results 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 has started on November 2013 and GPM core observatory will be launched in February 2014. DPR orbital check out will be started in March 2014 and it will be completed in April 2014. The orbital check out status of DPR will be reported .