Status of algorithm development and CAL/VAL plans in the JAXA GPM project

摘要

The Global Precipitation Measurement (GPM) started as an international project and a follow-on and expansion of the Tropical Rainfall Measuring Mission (TRMM). The GPM mission consists of two different categories of satellites. One is a TRMM-like core satellite carrying both active and passive microwave instruments, jointly developed by Japan and the US. The other is a constellation of satellites carrying passive microwave sensors and provided by partner agencies.rnA Dual-frequency Precipitation Radar (DPR) for the GPM core satellite is being developed by JAXA and NICT, and consists of Ku- and Ka-band precipitation radars to measure light rainfall and snowfall as well as moderate-to-heavy rainfall. One major objectives of GPM is to contribute to operational utilization, and frequent and accurate precipitation products, at less than 3-hour intervals, will be produced by combining multi-satellite microwave radiometers and geostationary IR information. DPR will provide accurate rainfall database to microwave radiometers, and enhance their algorithms, which will be used to make frequent rainfall map.rnThe DPR LI algorithms are being developed by JAXA. Collaboration activities between Japan and the US have started to develop L2/3 rainfall algorithms for DPR, and DPR/GMI combined products. Research activities to develop algorithms for rainfall map products have been underway both in Japan and the US. Validation activities in JAXA will be focused on contributions to algorithm development before and after the launch, as well as evaluation of the quality of rainfall products. Pre-launch validation will include ground-based campaigns and utilization of synthetic data produced by numerical models.