Calculation of the RCS from the double reflection between planar facets and curved surfaces

A method to obtain the contribution to the monostatic radar cross section (RCS) due to double reflections between plane facets and curved surfaces is presented. This method is applied to arbitrary targets modeled by NURBS (non-uniform rational B-spline) surfaces. The method developed is a combination of geometrical optics (GO) and the stationary phase method (SPM).