Primary research interests are the retrieval of hydrologic parameters from satellite-based passive microwave measurements and their applications at NOAA. This has included work with the Nimbus-7 SMMR, DMSP SSM/I and SSMIS, NOAA AMSU and MHS, TRMM TMI , the Aqua AMSR, the GCOM AMSR-2, S-NPP and NOAA ATMS and the GPM GMI sensors. Several of the algorithms he has been developed are used operationally by FNMOC, NESDIS and NASA. Ralph is a member of the AMSR science team, the NASA Precipitation Measurement Missions Science team, leads NESDIS/STAR’s Precipitation and Hydrology Science Teams, and NESDIS/JPSS Hydrology Initiative.