Angular correlation function and scattering coefficient of electromagneticwaves scattered by a buried object under a two-dimensional rough surface

We study three-dimensional (3-D) electromagnetic wave scattering from a bur ied object under a two-dimensional (2-D) random rough surface. The surface integral equations of wave fields are used for the rough surface and the su rface of the buried object. The surface fields are then solved by the metho d of moments. The scattered wave field from the object is represented by th e rough-surface field so that the matrix equation can be salved efficiently by means of the sparse-matrix canonical-grid method. Numerical simulations are illustrated for a perfectly conducting sphere buried under a 2-D rough surface. Both the scattering coefficient (normalized radar cross section) and the angular correlation function (ACF) are calculated. The study of 3-D electromagnetic scattering allows the use of azimuthal angular averaging a nd the study of cross polarization and the polarization angular correlation function (PACF). It is found that the ACF is more effective in suppressing the clutter that is due to the rough-surface scattering, and the PACF is m ore useful for the detection of the buried object. (C) 1998 Optical Society of America [S0740-3232(98)00412-8].