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

In this paper, an enhanced band-pass filtering algorithm based on the 3-D Fourier transform is presented to extract ocean wave information from X-band nautical radar images. After the current velocity is determined by an iterative least-squares method with appropriate thresholds, the components of the image spectra will be classified as the fundamental, the first-order harmonic waves and noise. In the proposed algorithm, only the fundamental components are used for wave spectra and parameter retrieval. The modified wave algorithm is first tested via numerical simulation. Further validation is then performed using field data. Unlike the previous wave analysis research that is conducted with horizontally polarized radar data, here, vertically polarized radar data is used. Retrieved results show good agreement with in-situ values obtained using a TRIAXYS wave buoy.