Level 1 algorithm development of spaceborne dual-frequency precipitation radar (DPR) for GPM

Abstract

Global Precipitation Measurement (GPM) started as an international mission and follow-on mission of the TRMM project to obtain more accurate and frequent observations of precipitation. The accurate measurement of precipitation will be achieved by the Dual-frequency Precipitation Radar (DPR) installed on the GPM core satellite. DPR consists of two radars, which are Ku-band (13.6 GHz) precipitation radar (KuPR) and Ka-band (35.5 GHz) radar (KaPR). Level 1 algorithm, which calculates engineering values, for processing the products of each KuPR and KaPR will be developed based on the PR level 1 algorithm. Japan Aerospace Exploration Agency (JAXA) is developing level 1 algorithm. Housekeeping (HK) and science telemetry data of the DPR is basically similar to that of PR except for pulse repetition frequency (PRF) and noise sampling. DPR will use variable PRF (VPRF) technique to obtain higher sensitivity under the limited resources on the spacecraft. Sampling methods of noise for each angle are different between PR and DPR. The information of VPRF table and noise sampling will be added to level 1 products of KuPR and KaPR. KaPR sampling simulation experiment using TRMM PR was carried out for half-day on 15 March 2007 to get the same geometry data of KaPR scanning in order to create synthetic data of level 1 products for development of higher-level algorithms of DPR and examine to make the best use of them in the critical design, operation and algorithm development for DPR. It successfully finished and we could get the simulation data with same geometry of KaPR scanning.