The characteristics of electromagnetic scattering from rough surface are investigated based on the Small Perturbation Method, the Kirchhoff Approximation and the Phase Perturbation. In X-band, the backscattering radar cross sections of random rough surfaces with different height root-mean-squares and correlation lengths are numerically analyzed. Backscattering and bistatic radar cross sections of 2-D and 3-D targets are calculated with the method of higher equivalent edge currents and comprehensive analysis, the results are in good agreetment with experimental data. In order to take into account the diffraction of the edge of targets, the method of equivalent edge currents, Physical Optics approximation and the reciprocity theorem method are combined to calculate the composite scattering field from a target above sea surface. The composite scattering field of square plates and cone-columns in different size above sea surface are also calculated, with the results improved from unconsidered diffraction. The influence of size, position and edge diffraction on the composite scattering field is analyzed. |