Observing System Simulation Experiment on The Accuracy of Global Satellite Mapping of Precipitation (GSMAP) by Future Small Precipitation Radar Constellation

Abstract

As one of the future precipitation observation missions discussed in Japan Aerospace Exploration Agency (JAXA), there is a concept of small spaceborne precipitation radar constellation in the Tropics. This can improve a quality of the multi-satellite precipitation product called Global Satellite Mapping of Precipitation (GSMaP) developed by the JAXA under the Global Precipitation Measurement (GPM) Mission if realized. In this study, an Observing System Simulation Experiment (OSSE) on accuracy of GSMaP caused by increases of spaceborne precipitation radar observation was evaluated over Japan area. It was found that the accuracy got better as the frequency of pseudo precipitation radar data increases. The morphed technique in the GSMaP was adopted also in well-known global precipitation map products such as NASA IMERG and NOAA CMORPH, and therefore, current results could be expected to be similar in experiments using those products.