After more than four and a half years since the launch of Sentinel-3A (S3A) and about two and a half years since the launch of Sentinel-3B, it is useful to assess the wind and wave data observed by the Synthetic Aperture Radar Altimeter (SRAL) instruments that are among the most important components of the payload of both satellites. Both altimeters, which are identical, operate fully in High Resolution Mode (HRM, which is also known as Synthetic Aperture Radar, SAR, Mode, or delay-Doppler altimetry, DDA). The only exceptions were one of the earliest cycles (27 days) during the commissioning phase of each satellite when the altimeters were configured to sense using the conventional Low-Resolution Mode (LRM).
Surface wind speed and significant wave height observed by S3A and S3B SRAL in near real time (NRT) have been monitored and validated against the corresponding parameters from the ECMWF Integrated Forecast System (IFS), in-situ buoy and platform instruments and other satellites (specifically: Jason-3, Cryosat-2 and SARAL/AltiKa) including cross-comparison since the availability of such data. S3A and S3B NRT Level 2 Surface Topography Mission (STM) Marine Product (SR_2_WAT) is routinely obtained from EUMETSAT Copernicus Online Data Access (CODA) are used for this purpose.
Daily, cyclic, seasonal and yearly assessments of the data are carried out routinely. Unlike the routine “short”-term assessments, the assessment period for the current study covers the data since the data were made available shortly after the launch of launch of both satellites. The evolution of quality of NRT Sentinel-3 global wind and wave data will be studied. The results will be presented.