Thursday, 13 February 2003: 4:00 PM
Comparison of high-resolution SAR image wit QuikSCAT wind measurements(Formerly paper number JP4.21)
QuikSCAT scatterometer data provide global measurements of wind speed and direction over the oceans at 25 kilometer resolution. Synthetic aperture radars now offer the prospect of measurements of wind speed at sub-kilometer resolution. For over two years. we have been routinely processing RADARSAT SAR imagery into wind speed estimates in near real time at part of the Alaska SAR Demonstration. The imagery routinely reveals high-resolution features near the air sea interface including von Karman vortices, intense gap flows, boundary jets, atmospheric internal waves, and convective cells. SAR imagery is not as extensive or complete as QuikSCAT scatterometer measurements, but offers the prospect of wind speed measurements in coastal areas where conventional scatterometers fail. Using two years of QuikSCAT data and RADARSAT SAR data, we show that wind speed measurements between the two agree to 1.3 m/s and that the optimum wind speeds are obtained when SAR and scatterometer data are merged together for a composite estimate.