Evaluation of marine radar as an ocean-wave-field detector through full numerical simulation

The importance of ocean waves parameters (propagation direction, mean period, significant wave height, etc.) is related to several aspects of a ships safety, efficiency in operation, routing, design, and maintenance. However, some available methods for obtaining those parameters have data limitations and inconvenient aspects. In severe weather conditions, an ocean-wave-field detector is necessary. This can provide two-dimensional ocean-wave-field information directly. Among other conventional methods, ship-borne wave radar has the ability to function as such a detector, and some researchers have tried to develop practical systems. A numerical approach using plan position indicator (PPI) images from conventional marine radars is proposed to retrieve valuable information from the ocean waves. A three-dimensional Fourier transform is applied to a set of consecutive radar PPI images to perform spectrum analysis. The removal of undesired elements in the spectrum is achieved by applying a hi-pass filter to remove static components, and by comparing the data with the expected dispersion shell to correct for nonocean-wave power. Numerical experiments under controlled conditions using simulated PPI images were performed through numerical simulations based on theoretical ocean-wave equations. The results include a comparison between the original wave parameters used in the simulation and the values retrieved from the spectrum analysis.