Research on key issues of extracting wind direction from HF surface wave radar oceanic backscatter

Based on the scattering mechanism between HF radio wave and sea surface, the key issues of inversing wind direction from the first-order oceanic backscatter of HF Surface Wave Radar(HFSWR) were researched, and an algorithm has been applied to the HFSWR data. Firstly, the foundational theory of inversing wind direction was discussed based on the first-order radar cross section equation. Secondly, the basic requirements of inversing wind direction were derived by the well-generated wave spectral model. Thirdly, the typical Longuet-Higgins and Donelan wind directional models were discussed and the appropriate directional spreading parameters were determined by both dogvane measured and HFSWR data. Finally, the algorithm was applied to the measured Doppler sea echo data. Seen from the results, the inversed wind direction shows good agreement with the measured wind direction of dogvane, and the wind direction ambiguity is almost eliminated. Therefore the algorithm turns out to be effective.