Performance of sentinel-3A SAR altimetry retrackers: The SAMOSA coastal sea surface heights for the baltic sea

Abstract

Performance of the Sentinel-3A SRAL altimeter data is evaluated in the coastal waters of the Gulf of Finland, Baltic Sea. Sea Surface Heights (SSH) were computed along three ascending passes nearby three tide gauge (TG) sites in Estonia. These SSH were compared to a high-resolution marine geoid model in conjunction with a TG corrected hydrodynamic model (HDM). The SAMOSA2 and SAMOSA+ retracker retrieved SSH values were inter-compared as well. The quality assessment yielded the root mean square error of 115 and 99 mm for the SAMOSA2 and SAMOSA+ retrieved Sentinel-3A SSH data, respectively. The near-zero mean of discrepancies shows that there is no significant systematic bias between the geodetic infrastructure and Sentinel-3A SSH data.