The Copernicus Sentinel-6 mission: Enhanced continuity of satellite sea level measurements from space

Last modified: 
March 25, 2021 - 4:08pm
Type: Journal Article
Year of publication: 2021
Date published: 06/2021
Authors: Craig Donlon, Robert Cullen, Luisella Giulicchi, Pierrik Vuilleumier, Richard Francis, Mieke Kuschnerus, William Simpson, Abderrazak Bouridah, Mauro Caleno, Roberta Bertoni, Jesus Rancaño, Eric Pourier, Andrew Hyslop, James Mulcahy, Robert Knockaert, Christopher Hunter, Alan Webb, Marco Fornari, Parag Vaze, Shannon Brown, Joshua Willis, Shailen Desai, Jean-Damien Desjonqueres, Remko Scharroo, Cristina Martin-Puig, Eric Leuliette, Alejandro Egido, Walter Smith, Pascal Bonnefond, Sophie Le Gac, Nicolas Picot, Gilles Tavernier
Journal title: Remote Sensing of Environment
Volume: 258
Pages: 112395
ISSN: 00344257

Given the considerable range of applications within the European Union Copernicus system, sustained satellite altimetry missions are required to address operational, science and societal needs. This article describes the Copernicus Sentinel-6 mission that is designed to provide precision sea level, sea surface heightsignificant wave height, inland water heights and other products tailored to operational services in the ocean, climate, atmospheric and land Copernicus Services. Sentinel-6 provides enhanced continuity to the very stable time series of mean sea level measurements and ocean sea state started in 1992 by the TOPEX/Poseidon mission and follow-on Jason-1, Jason-2 and Jason-3 satellite missions. The mission is implemented through a unique international partnership with contributions from NASA, NOAA, ESA, EUMETSAT, and the European Union (EU). It includes two satellites that will fly sequentially (separated in time by 5 years). The first satellite, named Sentinel-6 Michael Freilich, launched from Vandenburg Air Force Base, USA on 21st November 2020. The satellite and payload elements are explained including required performance and their operation. The main payload is the Poseidon-4 dual frequency (C/Ku-band) nadir-pointing radar altimeter that uses an innovative interleaved mode. This enables radar data processing on two parallel chains the first provides synthetic aperture radar (SAR) processing in Ku-band to improve the received altimeter echoes through better along-track sampling and reduced measurement noise; the second provides a Low Resolution Mode that is fully backward-compatible with the historical reference altimetry measurements, allowing a complete inter-calibration between the state-of-the-art data and the historical record. A three-channel Advanced Microwave Radiometer for Climate (AMRsingle bondC) provides measurements of atmospheric water vapour to mitigate degradation of the radar altimeter measurements. The main data products are explained and preliminary in-orbit Poseidon-4 altimeter data performance data are presented that demonstrate the altimeter to be performing within expectations.

Freely available?: 
Yes
Summary available?: 
No