Double scatter radar cross sections for two dimensional random rough surfaces-high frequency approximation

Full wave solutions for the single and double scatter radar cross sections from two dimensional random rough surfaces are obtained. The solutions are given as multidimensional integrals. The high frequency approximation is applied to these expressions to reduce the dimensions of the integrals. The incident waves are assumed to be plane waves. The large radius of curvature approximation is assumed in this work. The high frequency double scatter expressions are given as four dimensional integrals and the single scatter cross sections is given in closed form. This work is an extension of the problem of double scatter from one dimensional random rough surfaces. The numerical results, using the high frequency approximations, show sharp enhancement in the backscatter direction at normal and oblique incident angles. This sharp enhancement is associated with the quasi anti-parallel double scatter path. The level and width of the peak in the backscatter direction depends on the mean square height and slope of the two dimensional random rough surfaces.