Retrieval of SEA Surface Radial Current Velocity based on Sentinel-1 Ocean Data

This paper uses the level-2 Ocean data (OCN) of Sentinel-1 Interferometric Wide swath (IW) model to retrieve the sea surface radial current velocity. The level-2 OCN data of IW mode includes two modules: radial surface velocity (RVL) and ocean wind field (OWI). The RVL module provides parameters such as radial Doppler frequency shift, which can be used to retrieve the sea surface current velocity. The OWI module provides wind field retrieved from the SAR image and is used as the input of the empirical model CDOP to remove the Doppler frequency shift caused by the sea surface wind-wave field. The retrieval results are verified by using HYCOM data, and the bias was less than 0.1m/s and the root mean square error was about 0.2m/s in 4 test areas, which showed good agreement and utility of Sentinel-1 Ocean data in retrieving ocean current data.