The Sentinel-6/Jason-CS satellite carries an advanced radar altimeter to monitor sea-level variability and the rate of sea-level rise, both globally and regionally. It builds on heritage from the Jason series of satellites, Copernicus Sentinel-3 and ESA’s CryoSat mission. It is also designed to act as the reference mission for other satellite altimeters. The satellite payload also includes an advanced microwave radiometer and a radio occultation package to measure atmospheric parameters. It will also complement ocean information from Sentinel-3 – the other member of the Copernicus altimetry constellation.