4.2 Comparison of Radarsat Sar-derived Winds with Buoy and Quikscat Measurements

Spaceborne synthetic aperture radars (SARs) measure surface radar cross section (RCS) with ground resolutions from 25 to 100 m. In turn, the RCS of the ocean surface is a function of wind speed and direction. Over the past few years, we have been routinely using RCS measured by the RADARSAT SAR to compute highresolution wind speed. We have converted over 3000 wide-swath SAR RCS images, provided by the Alaska SAR Facility (ASF), into high-resolution wind speeds. SAR images have covered both the East Coast of the United States and Gulf of Alaska and Bering Sea regions. To validate these SAR-derived wind speeds we have systematically compared them to model, buoy, and, most recently, QuikSCAT scatterometer wind speed measurements. Thus far, the standard deviations of SAR wind speeds with respect to buoy or QuikSCAT wind speeds are less than 2 m/s.