Directional sea spectrum determination using HF Doppler radar techniques

Second-order features in HF radar Doppler spectral data are compared with a theoretical model of the radar spectrum. The model is the corner reflector double-scatter model which employs a more realistic directional sea spectrum model than those used in earlier works. It includes a frequency-dependent angular spreading function and assumes the existence of spectral energy over a full arising from an apparent second-order wave-wave interaction. Comparison is made with ground wave data collected at the NRL/NOAA/ITS San Clemente Island HF radar.