THE INITIATION OF THE SENTINEL CONSTELLATION OF OCEAN COLOR (OC) IMAGERS IN EUROPE BY THE COPERNICUS PROGRAM PROVIDES THE POTENTIAL FOR A POWERFUL NEW TOOL KIT FOR U.S. AND OTHER FOREIGN RESEARCHERS, WITH ALL DATA BEING FREELY AVAILABLE TO THE INTERNATIONAL COMMUNITY. CHALLENGES TO OPTIMIZE UNCERTAINTIES FOR SENTINEL IMAGERS GOING FORWARD INCLUDE 1) RIGOROUS VALIDATION THAT INVOLVES THE CRITICAL ASPECT OF THE BIDIRECTIONAL REFLECTANCE DISTRIBUTION FUNCTION (BRDF), WHICH IS OVERLOOKED, TO OUR KNOWLEDGE, IN CURRENT GLOBAL CALIBRATION AND VALIDATION EFFORTS AS THESE ONLY CONSIDER NADIR VIEWING, AND 2) IMPROVED OPERATIONAL ALGORITHMS FOR INLAND AND OCEAN WATERS THAT INCORPORATE THE BRDF. THESE CHALLENGES HAVE PROMPTED THE EU TO RECENTLY FUND SEVERAL NEW PROGRAMS SUCH AS WATERHYPERNET, HYPERNETS, AND COASTOBS TO DEVELOP NEXT GENERATION VALIDATION CAPABILITIES WITH HYPERSPECTRAL DATA AT MULTIPLE VIEWING ANGLES. OUR PROJECT HAS TWO BROAD OBJECTIVES: 1) PARTICIPATE IN DEVELOPING AND TESTING FUTURE VALIDATION CAPABILITIES FOR OC IMAGERS IN THE SENTINEL CONSTELLATION; AND 2) ASSESS PERFORMANCE OF THE ZTT ALGORITHM FOR SENTINEL OC IMAGERS, WORKING TOWARDS OPERATIONAL IMPLEMENTATION. THESE OBJECTIVES WILL BE CARRIED OUT THROUGH DIRECT INVOLVEMENT IN WATERHYPERNET AND HYPERNETS VALIDATION PROGRAMS AS WELL AS WITH THE COPERNICUS OC OPERATIONAL PROCESSING FACILITY (CMEMS-OCTAC) WHERE DR. BRANDO SERVES AS DEPUTY LEADER. DR. RUDDICK IS ALSO INTERESTED IN INSTALLING A WATERHYPERNET SYSTEM ADJACENT TO AN EXISTING AERONET-OC SITE WE HAVE JUST INSTALLED IN LAKE OKEECHOBEE, FL IN THE 2020 TIME FRAME.