A CALIBRATION-FREE METHODOLOGY TO ESTIMATE SIGNIFICANT WAVE HEIGHT USING TIME-SEQUENCES OF X-BAND MARINE RADAR IMAGES

This research applies a calibration-free method to estimate the significant wave height (Hs) using the amplitude of the electromagnetic signal acquired by a coherent on receive X-Band radar that operates in horizontal polarization. The experiments were conducted from 8th to 11th November 2015 at the research platform FINO-3 located in the German Bight of the southern North Sea. Unlike the traditional wave dispersion based procedure, the proposed method uses other filtering and signal processing techniques to invert the sea surface elevation from the sea clutter radar images. The comparison of radar-derived H-s to in-situ measurements collected by a waver rider buoy resulted in a root mean square error of 0.33 m with a bias of 0.09 m and a correlation coefficient of r =0.92. Validation of H-s estimates considering the AWAC measurements shows a RMSE of 0.24 m with a bias of 0.18 m and r =0.96. Therefore, this calibration free methodology is very well suited to be applied to X-Band marine radars operated from offshore platforms as well as ships.