A C-band Geophysical Model Function for Determining Coastal Wind Speed Using Synthetic Aperture Radar

A new geophysical model function (GMF), called C_SARMOD2, has been developed to determine coastal wind speed. A total of 3078 RADARSAT-2 and Sentinel-1A VV-polarized SAR images were collocated with in situ buoy measurements, which was used to derive transfer functions and then to validate the wind speed retrievals. The wind speeds retrieved by the proposed C_SARMOD2 model are more similar to buoy measurements with almost no bias and a root mean square error of 1.84 m/s. Two representative quad-and dual-polarization SAR images acquired from coastal regions are used as case studies to examine C_SARMOD2 performances. The case study and statistical validation results suggest that the proposed C_SARMOD2 has the potential to measure coastal wind speeds at sub-kilometer resolutions and also advocate for the necessity of revisiting the methodologies for ocean surface wind speed measurements in coastal areas.