An exeriment for high speed retrieval by ENVISAT-ASAR cross-polarized observations

We present a new empirical C-band cross-polarization ocean backscatter model for high wind retrievals, from ENVISAT-ASAR. The model relates normalized radar cross section (NRCS) in cross-polarization (VV/VH) to the wind speed at 10-m height. This wind retrieval model has the remarkable characteristic that it is independent of SAR radar incidence angles or wind directions but is extremely linear with respect to wind speeds, especially high winds. To evaluate the accuracy of the proposed model, winds were retrieved from a dual-polarization ASAR image of storm surge and to retrieve wind direction by CMOD5, using the new model and compared with ASAR data. A root mean square error of retrieval wind speed is about 1.13m/s in new empirical C-band model and wind direction is about 16.16°.