Extracting Usable Geophysical Doppler Properties from Sentinel–1 for Coastal Monitoring

In 2005, the Doppler frequency from space-borne SAR was demonstrated to contain sea surface current signature. From mid-2007 to 2012, a first Doppler frequency grid from ENVISAT ASAR was proposed by ESA for exploring this information. The OCN-RVL product from Sentinel-l was supposed to provide a Doppler frequency with a better accuracy and resolution than ASAR. The retrieved radial surface velocity could then be directly used by the oceanographic community. However, the Doppler frequency as provided by OCN-RVL today contains a strong signal processing signature that prevents it from being usable in practice. In this paper we propose an algorithm, based on the Doppler properties over land, that is capable to cancel the signature and extract exploitable geophysical information. By making the algorithm freely available, we offer to the coastal community the means to take advantage of this information for the analysis of wind, wave, and sea current signatures, at a spatial resolution of 2 by 2km
²
.