Electromagnetic scattering by targets over a real Earth

The finite element method is applied to the boundary value problem of the scatterer. To account for the presence of a real Earth, multiple expansions are used to deal with the air-earth half spaces. The technique developed is applicable for metallic or dielectric targets. Computations have been made for scatterers in both free space and the presence of a real Earth. The accuracy and reliability have been checked by shifted sphere solutions, comparison with bistatic radar scattering experiments, and the reciprocity theorem. These comparisons have confirmed the validity of the method.