Sea Level

About the SRAL

Thumbnail - Sentinel-3 Launch - Sea Level

The dual-frequency Synthetic Aperture Radar Altimeter (SRAL) will provide sea surface topography measurements in “SAR mode”, i.e. with a spatial resolution as narrow as 300m.

SRAL is supported by a microwave radiometer for atmospheric correction and by a DORIS receiver, Global Navigation Satellite System, and laser retroreflector to determine its position in space with pinpoint accuracy.

The SRAL will be used to determine sea and lake surface height, significant wave height, surface wind speed, and sea ice height and thickness.

Last Updated:  Thursday, 15 March 2018

Sea level is a key indicator of climate change as it integrates the response of the climate system to continuing greenhouse gas emissions: i.e. ocean thermal expansion, glacier melting and ice mass loss from the Greenland and Antarctic ice sheets

Anny Cazenave Senior Scientist at the Laboratoire d’Etudes en Geophysique et Oceanographie Spatiale


Altimetry constellation

Monitoring sea surface topography and mean sea level for operational oceanography and climate monitoring requires a constellation of several altimeter missions, including one reference mission.

A constellation of at least three altimetry satellites, with different orbits and repeat cycles, is needed to provide global coverage and to sample ocean variability at scales ranging from eddies, to large gyre currents, tropical oscillations like El Niño, and general circulation.

With the optimum combination of the Jason-3 and the future Sentinel-6 reference altimeter missions, and the altimeter mission of Sentinel-3, Europe will, in cooperation with the United States, provide both the reference and the backbone of the constellation expected to meet the requirements for operational oceanography and sea level monitoring for the next two decades.

Access ocean altimetry data via EUMETSAT and CMEMS.

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