The proposal is responsive to the NASA Research Opportunities in Space and Earth Sciences (ROSES) 010 A.26 Call: Earth Science U.S. Participating Investigator. The proposal will support the involvement of the proposal team in the development and validation of data products from the European Space Agency’s Sentinel 3 mission. The Sentinel 3 mission is designed to support GMES (Global Monitoring for Environment and Security) activities for land and sea applications it will provide global, moderate resolution coverage in 21 spectral bands through the Ocean Land Colour Instrument (OCLI). The launch of the first satellite is scheduled for 2013. The proposal team will be involved in the Sentinel 3 science team and will contribute, both in the pre-launch and in the post-launch phase, to data products related to: - Surface reflectance - Burned area detection - Active fires detection and Fire Radiative power characterization Building on the extensive expertise gathered by the proposal team in the MODIS and VIIRS missions, and in their involvement in international coordination activities (GEO, CEOS and GOFC), the focus will be on the development of integrated validation strategies for NASA and ESA products, on the sharing of validation data, and on ensuring the compatibility of the Sentinel 3 data products with the equivalent NASA products, in order to allow for their combined exploitation