Backscattering From Electrically Large Target Above Nonlinear Sea Surface

Abstract

Abstract-The composite scattering of an electrically large target above nonlinear sea surface is analyzed based on the reciprocity theorem. The two-dimensional nonlinear sea surface is simulated with the Fast Fourier transform (FFT), with which the phase modified two-scale method is utilized to calculate the scattering field of the wind-driven sea surface. The electromagnetic currents of the sea surface, which are excited with plane wave, are calculated with the iterated Kirchhoff approximation (KA). The coupling scattering between the target and the sea surface, which includes the complex scattering matrix of composite scattering, is ingeniously reduced to the integrals involving the target scattering and high order currents of sea surface. A sensitivity analysis is performed for the dependency of the coupling scattering on the target features. The relationship of the full composite scattering model with the sea state is examined, which provides theoretical basis for the target recognition.