Sentinel-3   Sentinel-3 is being developed by ESA for the European Global Monitoring for Environment and Security programme. The mission's main objective is to measure sea-surface topography using radar altimetry, sea- and land-surface temperature using an advanced visible/thermal radiometer and ocean- and land-surface colour using a visible spectrometer.   Sentinel-3 will benefit a broad range of services for the marine environment by delivering information to advance ocean forecasting systems, including sea-water quality, eutrophication, wave height, sea-ice extent, global sea-level rise, as well as data for land-based services. Last update: 7 March 2011