Measurement of ocean surface waves by HF radars using a direction finding receive antenna

HF radars are capable of measuring surface currents and ocean waves. Existing algorithms for wave retrieval make use of the second-order side bands of the HF Doppler spectrum. However, the resolution of side bands requires an array of receive antennas which permits the application of beamforming techniques. The authors present an empirical method which relies on the correlation between the standard deviation of the HF Doppler peaks and the significant waveheight weighted by an azimuthal function. Using data of two radar sites the significant waveheight and the mean wave direction can be retrieved. This method is applied to HF measurements performed with a direction finding array.