CoAuthors

Amandine Guillot (CNES, France); Nicolas Picot (CNES, France); Matthias Raynal (CLS, France); Sylvie Labroue (CLS, France); Jean-Christophe Poisson (CLS, France); Pierre Thibaut (CLS, France)

The Sentinel-3 Mission (S-3) is part of the Global Monitoring for Environment and Security (GMES/Copernicus) European initiative. For oceanic applications, the S-3 mission will deliver continuity to existing ESA ERS, Envisat and CryoSat missions. The topography payload consists in a Doppler altimeter SRAL, a microwave radiometer MWR, and 3 instruments for precise orbit computation purposes (GNSS, DORIS and laser reflector). The Sentinel-3 satellites (A and B) will fly on a new orbit with a 27-days cycle.
The SRAL instrument is a nadir Ku/C altimeter, with two operating modes: the low resolution mode (LRM), used on all past oceanographic missions and the high resolution mode (SAR) used for the first time on CryoSat. The SAR mode (also called Delay Doppler) provides a better along track resolution (around 320m) with respect to the LRM mode.

The Sentinel-3A satellite has been launched in February 2016, and CNES (with the support of CLS) has provided a strong support to ESTEC project for the topography calibration and validation during the commissioning phase over all surfaces. In this paper, we will present a first quality assessment of SRAL measurements in SAR mode on deep ocean, coastal areas, inland waters and polar regions.