Ocean surface wind speed retrieval from C-band quad-polarized SAR measurements at optimal spatial resolution

Abstract

ABSTRACT This work investigates the effect of the resampling spatial resolution (RSR) on the retrieval of ocean surface wind speed from satellite-borne Synthetic Aperture Radar (SAR) images. For this purpose, 358 RADARSAT-2(RS-2) fine-beam quad-polarized SAR images and in-situ National Data Buoy Centre (NDBC) and China State Oceanic Administration (SOA) buoy measurements from selected geographic locations are used in this paper. In order to obtain better accuracy SAR-retrieved wind speeds, CMOD5.N function, Z2011 polarization ratio (PR) model and C2PO model constitute the best models for VV-, HH- and cross-polarized SAR images, respectively. The resulting statistical analysis suggests that better accuracy wind speeds can be retrieved at somewhat coarser resolutions. The optimal RSR for the VV-, HH-, VH- and HV-polarized channels are 850, 1050,1350 and 1450 m, respectively, with RMSEs of 1.74, 2.03, 1.61 and 1.83 m/s.