Rainfall Estimates from GPM's Constellation of Radiometers

The GPM concept consists of a core satellite and a constellation of passive microwave radiometers. The core satellite was launched on February 28, 2014 and carries a dual frequency radar along with the GPM Microwave Imager (GMI). The core satellite has two primary functions. The first is to provide the highest possible quality of precipitation estimates to anchor our understanding of global precipitation along with detailed descriptions of the precipitation structures that produce this precipitation. The second objective is to use the reference precipitation cloud properties as a guide to unify and collate estimates from a constellation of existing microwave sensors in low Earth orbit. While much of the initial work on GPM has focused on the core satellite, the high quality of the initial products has allowed progress on the constellation product as well. This talk will provide initial results from the Microwave Imagers (GMI, TMI, AMSR2, SSMIS-F16, F17, and F18) that form part of the constellation. Questions related to instantaneous accuracy of the constellation radiometers as well as 6-hour and daily accumulations that can be derived from these satellites will be presented. Comparisons are made against surface based rainfall estimates from the National Severe Storms Laboratory's Stage IV precipitation product over the continental United States as well as radar estimates belonging to the OPERA network over Europe.