December 18, 2020


CNES President Jean-Yves Le Gall and Alain Ratier, Director General of Eumetsat (EUropean organisation for the exploitation of METeorological SATellites), signed a cooperation agreement covering data from the Nadir altimeter payload on the SWOT (Surface Water and Ocean Topography) satellite. The Nadir payload includes the French Poseidon-3C and DORIS altimeters, complementing the KaRIn wide-swath radar interferometer designed to measure the topography of surface waters and oceans at high resolution.

As the supplier of Poseidon-3C and DORIS, CNES will store the data from the two instruments at the SWOT mission centre based at its Toulouse facility. The cooperation agreement sets out the terms and conditions under which Eumetsat will be able to access, exploit and distribute Nadir altimeter data to its user community. These data will be a precious aid for:
-    National weather services in Eumetsat’s member states and for the European Centre for Medium-range Weather Forecasts (ECMWF)
-    Research scientists, to conduct operational climate monitoring and detection of global climate change phenomena

The SWOT mission is led jointly by CNES and NASA, with contributions from the UK Space Agency (UKSA) and the Canadian Space Agency (CSA). Global warming is likely to have far-reaching effects on freshwater flows from lakes to rivers and reservoirs, with significant social consequences. The SWOT satellite will use radar technology to characterize the world’s oceans, coasts, rivers and lakes in order to gain new insights into how they change over time and to obtain a clearer picture of their impact on farming, industry and human populations. The satellite is currently in development and scheduled to launch end February 2022 for a mission planned to last three and a half years.

The longstanding cooperation between CNES and Eumetsat in the domain of Earth’s atmosphere and observation of the oceans from space is enshrined in a series of agreements. These include the cooperation agreement on Europe’s contribution to the OSTM/Jason-2 mission signed in 2006, the agreement on Europe’s contribution to the Jason-3 programme signed in 2010 and the agreement on the Sentinel-6/Jason-CS mission signed in 2017.

Pascale Bresson    Press Officer    Tel. +33 (0)1 44 76 75 39
Raphaël Sart    Head of Media    Tel. +33 (0)1 44 76 74 51