An alternative algorithm for wave information extraction from X-band nautical radar images

A new algorithm is presented to extract ocean wave information from X-band nautical radar images. Based on the iterative least-squares (LS) current method in which the samples of the image spectra are classified as the contributions from fundamental, first-order harmonic, and higher harmonics waves or noise, the proposed algorithm uses the classified fundamental and first-order harmonic wave components for wave spectra and parameter retrieval directly. Unlike the previous wave analysis in which a band-pass filter is required subsequently to eliminate the non-wave contributions after current velocity is obtained, the proposed algorithm simplifies the wave retrieval without such a bandpass filter. Harmonic wave components are also accounted for in the wave retrieval process. This algorithm is applied to both simulated and field radar images, and results from both types of data show that this modified wave algorithm is effective.