Numerical Simulation and Electromagnetic Scattering Calculation of Freak Waves Based on Different Wave Spectra

Based on the Longuet-Higgins random wave theory, an improved phase modulation method is used to simulate freak waves. This method can generate freak wave at specific positions, the spectral structure of the target spectrum is also maintained. By comparing different wave spectra, modulation intervals and wave steepness, the accuracy of simulation has been improved. After the simulated freak waves are obtained, we propose an electromagnetic scattering model based on the two-scale method (TSM). By comparing the calculation results of the normalized radar cross section (NRCS) of the freak wave and its background wave, it is concluded that the NRCS value of freak wave is obviously low and different from the background wave. In practical ocean engineering, freak waves can be detected by comparing different NRCS.