Retrieval of ocean wave characteristics from K-band radar

A method is proposed for the retrieval of period, height and direction for ocean waves from K-band radar signal. This method is designed for the K-band frequency modulated continuous wave radar mounted on an unmanned surface craft. The K-band radar signals transmitted, reflected and received at sea surface are analyzed. The frequency of the received signal shifts with water particle movements. The relationship between the frequency shift and the wave characteristics is established. The ocean wave characteristics can be retrieved through extracting the frequency shift and analyzing the periodicity and the amplitude of the frequency shift with the deterministic relationship. Numerical simulations about the retrieval processes under some wave conditions have been performed and the results show that the retrieval method is reasonable and feasible for the K-band radar. Besides, a sea surface experiment has also been carried out with a K-band radar and the experimental results are approximate to the measurements results of a wave rider buoy.