Comparison of RADARSAT SAR-derived wind speeds with buoy and QuikSCAT measurements

The radar cross section (RCS) of the ocean surface depends on both wind speed and direction. By using estimates of the wind direction from an atmospheric model plus RCS measurements from the RADARSAT-1 synthetic aperture radar (SAR), we processed over 3000 wide-swath SAR RCS images into wind speed fields. We have validated these wind fields against both buoy and QuikSCAT scatterometer measurements. The standard deviation of SAR wind speeds with respect to buoy or QuikSCAT wind speeds Is less than 2 m/s. If the QuikSCAT wind directions are used rather than the model directions for the SAR wind speed retrieval, the agreement between SAR and QuikSCAT wind improves to a standard deviation of 1.5 m/s.