Extraction of wind direction from the HF hybrid sky-surface wave radar sea echoes

In this article, we develop an experiment to obtain the sea state parameters by the HFHSSWR and the in situ instruments. The wind direction is extracted, and the results are compared with the in situ data. In addition, the wind direction ambiguity was eliminated by the ML method. The results show that it is feasible to extract the wind direction using the HFHSSWR.