THE IOWA FLOOD CENTER (IFC) AND NASA'S GPM GROUND VALIDATION PROGRAM WILL TEAM UP TO PROVIDE HIGH-RESOLUTION RADAR-BASED RAINFALL MAPPING FOR THE SMAPVEX CAMPAIGN PLANNED FOR THE SOUTH FORKS IOWA REGION IN THE SUMMER OF 2016. TWO X-BAND POLARIMETRIC RADARS WILL BE DEPLOYED OUTSIDE OF THE SOUTH FORK WATERSHED BOUNDARIES AND WILL SCAN REGULARLY DURING RAINFALL EVENTS. THE RADARS WILL BE COMPLEMENTED WITH TWO OPTICAL DISDROMETERS AND A VERTICALLY POINTED K-BAND MICRO RAIN RADAR BOTH PROVIDED BY THE GPM GROUND VALIDATION PROGRAM. THESE INSTRUMENTS WILL BE DEPLOYED AND MAINTAIN BY IFC ENGINEERS. THE COLLECTED DROP SIZE DISTRIBUTION DATA WILL ALLOW DEVELOPMENT OF CUSTOM POLARIMETRIC ALGORITHMS FOR MAPPING RAINFALL INTENSITY WITH SPATIAL RESOLUTION OF ABOUT 100 M AND TEMPORAL RESOLUTION OF 1-2 MINUTES. THE MAPS WHEN COMBINED WITH THE IN-SITU RAIN GAUGE NETWORK DATA WILL RESULT IN HIGH ACCURACY RAINFALL ACCUMULATION FIELDS. THESE DETAILED RAINFALL ACCUMULATION MAPS WILL ALLOW RESOLVING SOIL MOISTURE FIELDS WITH HIGH SPATIAL ACCURACY AND TRACKING ITS CHANGES OVER TIME. IN ADDITION THEY WILL PROVIDE AN OPPORTUNITY FOR ULTRA-HIGH RESOLUTION OF RAINFALL-RUNOFF MODELING FOR STREAM FLOW FORECASTING. BOTH PROBLEMS ARE OF HIGH SCIENTIFIC AND PRACTICAL INTEREST TO THE IFC AND THE SOIL MOISTURE RESEARCH COMMUNITY.