Study On The Modified Two-scale Method Of Electromagnetic Scattering From Time-varying Rough Sea Surface With Foams

In this paper, some representative sea wave spectrums modes and characteristics have been analyzed. The direction function are added to the sea wave spectrums modes, and the Monte Carlo method is applied to simulate the two-dimensions rough sea surface in different wind speeds and wind regions for embodying the dimensional anisotropy of sea surface.The slant of the non-gauss surface waves is taken into account for further study on the modify two-scale method. Non-gauss surface bi-spectrums function is added to the first-order scattering coefficient of classical small perturbation method for explaining the difference between upwind and downwind observations. Meanwhile, in the new modified model, the effects of the shadow function, the slope and the curvature of the surface on the scattering are also considered.Based on the new modified two-scale method, the coverage of the deep ocean whitecaps is further studied. The model of volume scattering of the whitecaps is given, and the backscattering coefficient of A. K. Fung spectrum ocean surface with a slap of the whitecaps is calculated with 25,40,55 incident angles and 2m/s to 16m/s wind speeds by the VRT. The data obtained from new modified two-scale method considering volume scattering will be closer to the experimental data than from the conventional method.The model of 2-D dynamic A.K.Fung spectrum ocean surfaces is simulated using the Monte Carlo method. The backscattering coefficients have been calculated by the new modified two-scale model considering volume scattering in different sea surface conditions and wave bands, obtaining sea-clutter series signal from the ocean surfaces in different conditions and the statistical characters.