Numerical simulation of bistatic scattering from a target at low altitude above rough sea surface under an EM-wave incidence at low grazing angle by using the finite element method

To study bistatic scattering from a target at low altitude above two-dimensional (2-D) randomly rough sea surface under an electromagnetic (EM) wave incidence at low grazing angle (LGA), a numerical approach of the finite element method (FEM) is developed. The conformal perfectly matched layer (PML), as the truncation boundary of the FEM, is employed to reduce the reflection error of planar PML in conventional FEM. Numerical code of our FEM is examined by available solution of the FBM (forward backward iterative) method. Bistatic and back-scattering from composite model of a target above randomly rough sea surface generated by Monte Carlo realization, and functional dependence upon the sea surface wind speed, target altitude, incident and scattering angles etc. are numerically demonstrated and discussed. This study presents numerical description for the observation principle and physical insight associated with the coupling interactions of a complex volumetric target and randomly rough sea surface.