Computerized Calculation of Complex Object RCS Using Physical Theory of Difiraction

The conception of elementary edge waves (EEW) in physical theory of difiraction (PTD) is shown to be robust in computer-aided calculation of radar cross section (RCS) of com- plex objects with metal edges. The backscattered fleld of near-the-edge inhomogeneous current, which is the difierence between actual current and its homogeneous part, given by physical optics (PO), is exhibited not to have magnitude singularities and phase jumps. The contribution to RCS from inhomogeneous current along a lengthy edge can be evaluated as a superposition of EEW. This contribution is shown to become negligible with increasing of deviation from the plane, perpendicular to the edge. Averaging of RCS, calculated with PTD, in angular and/or frequency range and some numerical correction of EEW for rounded edges and thin plate ends permit widening the scope of PTD application.