THE PRINCIPAL INVESTIGATOR HAS EXTENSIVE EXPERIENCE IN THE INTER-CALIBRATION WORK PROPOSED. HE HAS ESTABLISHED TOOLS AND LONG-TERM INTERACTIONS WITH THE INTERCALIBRATION WORKING GROUP ( XCAL TEAM ), WHICH WILL ALLOW A LOW-RISK APPROACH AND MINIMIZE COST. ALGORITHMS ALREADY EXIST THAT MEET THE MISSION REQUIREMENTS HOWEVER, THIS GRANT SUPPORTS RESEARCH TO IMPROVE ALGORITHMS AND APPLY THEM TO FUTURE SENSORS TO BE ADDED TO THE GPM CONSTELLATION SO THAT THE GPM MISSION CAN CONTINUE PRODUCING AND POTENTIALLY IMPROVE THE HIGH-QUALITY GPM LEVEL 1C DATASET. THIS PROPOSAL IS ALSO IMPORTANT AS IT WILL DEVELOP ALGORITHMS FOR CUBESAT RADIOMETERS, USING CURRENT TROPICS DATA THAT CAN THEN BE EXTENDED TO FUTURE CUBESATS TO BE INCORPORATED INTO THE GPM CONSTELLATION.