November 21, 2017


The Sentinel-3 mission is the result of close collaboration between ESA, the European Commission, Eumetsat, industry, service suppliers and data users.

ESA and Eumetsat share responsibility for ensuring that the mission runs smoothly. After the successful in-orbit commissioning phase during the first five months of the mission to check out all of the satellite’s functions, ESA handed over operations to Eumetsat.

ESA is responsible for operating the Sentinel-3 ground segment for land surface products and for continuous improvement of data and products through research and development. Eumetsat is responsible for supplying marine products and for satellite operations.

CNES's role

Under a cooperation agreement with ESA, CNES supplied a new version of the DORIS instrument vital for deducing sea surface height from the radar altimeter data. Besides DORIS, CNES is also providing expertise for many other aspects of the Sentinel-3 mission, notably for processing and characterization/validation of the altimetry instruments (altimeter, radiometer, GNSS and DORIS), as well as characterization of the optical instruments (OLCI and SLSTR).

This work was conducted from the start of the Sentinel-3 project on behalf of ESTEC for the Sentinel-3A development and validation phases, and for ESRIN during in-orbit commissioning. Work is ongoing for the B, C and D models of this series of satellites.