Mathew R. Schwaller

A prototype Validation Network (VN) is currently operating as part of the Ground Validation System for NASA’s Global Precipitation Measurement (GPM) mission. The VN supports precipitation retrieval algorithm development in the GPM prelaunch era. Postlaunch, the VN will be used to validate GPM spacecraft instrument measurements and retrieved precipitation data products.

To improve the fidelity of radiometer-based rainfall estimates over land at short temporal and spatial scales, the Global Precipitation Measurement mission (GPM) requires development of physically-based passive microwave (PMW) precipitation retrieval algorithms anchored by dual-frequency precipitation radar (DPR) drop size distribution (DSD), hydrometeor profile and rain rate retrievals.

A Validation Network (VN) prototype is currently underway that compares data from the Tropical Rainfall Measuring Mission (TRMM) satellite Precipitation Radar (PR) to similar measurements from the U.S. national network of operational weather radars. This prototype is being conducted as part of the ground validation activities of the Global Precipitation Measurement (GPM) mission. The purpose of the VN is to provide a means for the precipitation community to identify and resolve significant discrepancies between the U.S.

The Global Precipitation Measurement mission (GPM) Ground Validation (GV) Science Implementation Plan (GVSIP) applies three overarching approaches to validation of GPM satellite constellation measurements, products, and algorithms. These approaches include: