Kinji Furukawa

The Global Precipitation Measurement (GPM) Mission for Science and Society

The GPM mission collects essential rain and snow data for scientific studies and societal benefit.

Development of the spaceborne Dual-frequency Precipitation Radar for the Global Precipitation Measurement mission

The Dual-frequency Precipitation Radar (DPR) installed on the Global Precipitation Measurement (GPM) core satellite is being developed by JAXA and NICT. This paper describes the mission objectives, the precipitation measurement method and techniques, and the construction of the DPR

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

The Dual-frequency Precipitation Radar (DPR) on the Global Precipitation Measurement (GPM) core observatory is developed by Japan Aerospace Exploration Agency (JAXA) and National Institute of Information and Communications Technology (NICT). GPM objective is to observe global precipitation more frequently and accurately. GPM contributes to climate and water cycle change studies, flood prediction and numerical weather forecast. GPM consists of GPM core observatory and constellation satellites carrying microwave radiometers (MWRs) and/or sounders (MWSs). The frequent measurement will be achieved by constellation satellites, and the accurate measurement will be achieved by DPR with high sensitivity and dual frequency capability. GPM core observatory is jointly developed by National Aeronautics and Space Administration (NASA) and JAXA. NASA is developing the satellite bus and GPM microwave radiometer (GMI), and JAXA is developing DPR. GPM algorithms for data processing are developed jointly. The DPR consists of Ku-band (13.6 GHz) radar suitable for heavy rainfall in the tropical region, and Ka-band (35.55 GHz) radar suitable for light rainfall in higher latitude region. Drop size distribution information will be derived which contributes to the improvement of rainfall estimate accuracy. DPR will also play a key role to improve rainfall estimation accuracy of constellation satellites. DPR proto-flight test at JAXA Tsukuba space center is finished and it is delivered to NASA for integration to the GPM observatory. In this paper, DPR PFT test result at Tsukuba space center, DPR status in the GPM observatory environmental test, and DPR on-orbit calibration plan will be presented.

Satellite system test status of The Dual-Frequency Precipitation Radar on the global precipitation measurement core spacecraft

The Dual-frequency Precipitation Radar (DPR) installed on the Global Precipitation Measurement (GPM) core satellite is being developed by JAXA and NICT. This paper describes mission objectives, technical performance, resource allocation, critical design, proto-flight test (PFT) of the DPR instrument and satellite system test status. The DPR system PFT has completed in February 2012. 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 started at NASA Goddard Space Flight Center. After completion of all satellite system tests, the GPM core spacecraft will be sent to JAXA Tanegashima Space Center and launched by H-IIA launch vehicle.

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

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.

The orbital operations status of the dual-frequency precipitation radar on the global precipitation measurement core spacecraft

The Dual-frequency Precipitation Radar (DPR) installed on the Global Precipitation Measurement (GPM) core satellite was developed by JAXA and NICT. This paper describes mission objectives, technical performance, resource allocation, design, proto-flight test (PFT) of the DPR instrument, satellite system test including launch operations and orbital check out results of the DPR. The DPR system PFT has completed in February 2012. 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 at NASA Goddard Space Flight Center. GPM core observatory was shipped to JAXA Tanegashima Space Center, JAPAN and Launch Site Operations has completed. GPM core observatory was successfully launched by H-IIA launch vehicle on Feb 28, 2014. DPR orbital check out had started in March 2014 and it was completed in May 2014. The orbital check out results of DPR is reported in this paper.

Preliminary design of the spaceborne dual-frequency precipitation radar for the global precipitation measurement

The dual-frequency precipitation radar (DPR) installed on the Global Precipitation Measurement (GPM) core satellite is being developed by JAXA and NICT. This paper describes the results of preliminary design of the DPR instrument.

Current status of the dual-frequency precipitation radar on the global precipitation measurement core spacecraft

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 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 nominal flight altitude is 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 ground test. 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 results of orbital checkout show that DPR meets its specification on orbit. After completion of initial checkout, DPR started Normal Operations and Initial Calibration and Validation period was started. JAXA conducted internal calibrations, external calibrations and phase code changes to mitigate KuPR sidelobe clutter effect. JAXA evaluated these operations results and concluded that DPR data could go public. DPR products were released to the public on Sep. 2, 2014 and Normal Observation Operation period was started. JAXA is continuing DPR trend monitoring, calibration operations to confirm that DPR keeps its function and performance on orbit.

Two years and four months orbital operations status of the Dual-frequency Precipitation Radar on the Global Precipitation Measurement core spacecraft

The Dual-frequency Precipitation Radar (DPR) installed on the Global Precipitation Measurement (GPM) core satellite was developed by JAXA and NICT. This paper describes mission objectives, technical performance, resource allocation, ground test results, orbital check out results and orbital operation status of the DPR. The DPR system PFT has completed in February 2012. GPM core spacecraft satellite system test has completed at NASA Goddard Space Flight Center 2013. GPM core observatory was shipped to JAXA Tanegashima Space Center, JAPAN and GPM core observatory was successfully launched by H-IIA launch vehicle on Feb 28, 2014. DPR orbital check out was completed in May 2014. DPR products released to the public on Sep. 2, 2014 and Normal Observation Operation period was started. The orbital operations status of DPR is reported in this paper.

Current status of the dual-frequency precipitation radar on the global precipitation measurement core spacecraft and the new version of GPM standard products

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 objective of the GPM mission is to observe global precipitation more frequently and accurately. 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. The inclination of the GPM core satellite is 65 degrees, and the nominal flight altitude is 407 km. The non-sunsynchronous circular orbit is necessary for measuring the diurnal change of rainfall. The DPR consists of two radars, which are Ku-band precipitation radar (KuPR) and Ka-band precipitation radar (KaPR). GPM core observatory was successfully launched by H2A launch vehicle on Feb. 28, 2014. DPR keeps its performances on orbit after launch. DPR products were released to the public on Sep. 2, 2014. JAXA is continuing DPR trend monitoring, calibration and validation operations to confirm that DPR keeps its function and performance on orbit. JAXA have started to provide new version (Version 4) of GPM standard products on March 3, 2016. Various improvements of the DPR algorithm were implemented in the Version 4 product. Moreover, the latent heat product based on the Spectral Latent Heating (SLH) algorithm is available since Version 4 product. Current orbital operation status of the GPM/DPR and highlights of the Version 4 product are reported.