THE OVERARCHING GOAL OF THIS RESEARCH PROJECT IS TO USE THE OU/NSSL NMQ SYSTEM (HTTP://NMQ.OU.EDU) AS A BRIDGETO PROVIDE A CONSISTENT REFERENCE RESEARCH FRAMEWORK FOR CREATING CONTERMINOUS US (CONUS)-WIDE ERROR CHARACTERIZATION OF PRECIPITATION RETRIEVALS ACROSS TRMM/GPM CORE AND CONSTELLATION SATELLITES. THIS CROSS-PLATFORM ERROR CHARACTERIZATION WILL CONSIDER INFLUENCING FACTORS AND WILL ACT AS A BRIDGE TO INTERCALIBRATE ACTIVE AND PASSIVE MICROWAVE MEASUREMENTS FROM THE GPM CORE SATELLITE TO THE CONSTELLATION SATELLITES. ANALYSIS OUTPUTS WILL PROVIDE FEEDBACKS TO PRECIPITATION RETRIEVAL ALGORITHM DEVELOPERS AND ALSO TO DEVELOPERS OF MERGED LEVEL-3 PRODUCTS. TASKS ARE: 1. ESTABLISH A TRUSTWORTHY REFERENCE PRECIPITATION DATABASE. CURRENTLY THE NMQ SYSTEM INCORPORATES DATA FROM ALL WSR-88D RADARS AND AUTOMATED RAIN GAUGE NETWORKS TO GENERATE CONUS-WIDE 1-KM 5-MINTUE 3-D PRECIPITATION PRODUCTS (HTTP://NMQ.OU.EDU). THE ON-GOING DUAL-POLARIZATION UPGRADE OF THE NMQ (Q3) WILL PROVIDE ADDITIONAL INSIGHT INTO THE MICROPHYSICS OF PRECIPITATION (PARTICLE SIZE DISTRIBUTION HYDROMETEOR TYPES) FOR VALIDATING SATELLITES BOTH ACTIVE AND PASSIVE SENSORS. THE UNCERTAINTY OF THESE PRODUCTS WILL BE QUANTIFIED. 2. PERFORM AN IN-DEPTH COMPARISON ANALYSIS BETWEEN GROUND BASED RADARS AND SPACE RADARS TRMM PRECIPITATION RADAR (PR) AND FUTURE A DUAL-FREQUENCY PHASED ARRAY RADAR (DPR) USING NMQ PRODUCT.