Development of level 1 algorithm of Dual Frequency Precipitation Radar (DPR) for the Global Precipitation Measurement (GPM)

The Global Precipitation Measurement (GPM) mission consists of the GPM core Observatory (satellite) and the constellation satellites. The GPM core Observatory launched at 3:37 on February 28, 2014 (JST) from Tanegashima Space Center in Japan. It carries the Dual-frequency Precipitation Radar (DPR) and the GPM Microwave Imager (GMI). The DPR consists of Ku-band precipitation radar (KuPR) and Ka-band precipitation radar (KaPR). These radars have developed by Japan Aerospace Exploration Agency (JAXA) and National Institute of Information and Communications Technology (NICT) [1] and GMI has developed by National Aeronautics and Space Administration (NASA). The DPR level 1 algorithm has been developed by the JAXA. The main roles of level 1 algorithm are limit check for fatal and caution incidents, orbital cut and calculation of geometric information and transformation for engineering value. JAXA also has the responsibility of calibration of the DPR. The calibration methods have two types. One is the internal calibration with onboard calibration system, and the other is the external calibration with Active Radar Calibrator (ARC). These calibrations will carry out densely by the public data release. This paper describes the concepts of the level 1 algorithm and the calibration methods.