Numerical simulations of the scattered field near a statistically rough air-ground interface

The two-dimensional problem of horizontally polarized wave scattering from an air-ground interface is considered. The diffraction problem is formulated by means of the extinction theorem, leading to a system of two simultaneous surface integral equations. The small-slope approximation has been used to solve this system. This solution was used as a fast forward solver in the Monte Carlo simulations of the scattered field near to the rough interface. Properties of the reflected field have been investigated for a single realization of the rough interface as well as for a statistical ensemble of such interfaces. Special attention has been paid to the phase of the reflected field (in the case of a single realization) and to the variance of the reflected field (in the case of a statistical ensemble), which has direct relation with the surface clutter in ground penetrating radars. A principal possibility to retrieve a surface profile from interferometric measurements of the reflected field near the surface is demonstrated.