Summary

Description

NASA is committed to measuring precipitation on a global scale. In 1997, NASA launched the Tropical Rain Measuring Mission which carried the first spaceborne precipitation radar (PR). Operating at 13.8 GHz, the PR demonstrated the potential of spaceborne radars to map global precipitation. To improve rainfall estimates, the next generation system being proposed for the NASA Global Precipitation Mission is a dual-wavelength (Ku/Ka-band) precipitation radar (DPR). Operating at Ku and Ka-band, it will yield additional information on the drop size distribution (DSD). Advanced ground-based Ku/Ka-band DPR systems are needed to develop and validate the retrieval algorithms that will be used by GPM. This proposed Phase I effort will investigate the required innovations to design and construct a novel, low-cost, scanning, dual-polarized DPR senor and sensor network. The focus will be on developing a low-cost ruggedized compact antenna, transceiver, power amplifier and real-time processing and communication subsystems. This advanced DPR sensor network will provide unprecedented spatial/temporal sampling and coverage and multiple methods to determine DSD: polarization, differential extinction, multi-look radar measurements of extinction. As a sensor network, limitations due to earth curvature, topography and ground clutter that affect the existing weather radar infrastructure can be overcome.