Retrieval of Sea Surface Wind Speed Using Spaceborne Millimeter-Wave Radar Measurements

Spaceborne millimeter-wave radars can acquire sea surface backscatter information under clear sky conditions. The analysis based on the classical sea surface scattering model and a matching data set of global CloudSat Cloud Profiling Radar (CPR) observations and AMSR-E sea surface parameters shows that the sea surface scattering cross section is significantly dependent on the sea surface wind speed (SSW) in the range of less than 13 m/s. Then, with CPR observations and the sea surface temperature as the input information, an SSW retrieval model under clear sky conditions is established using neural networks. Retrieval results show that the correlation coefficient and the RMS error, between the millimeter-wave cloud radar SSW and the AMSR-E SSW, are approximately 0.95 and 0.97 m/s, respectively.