Special problems in applying the physical optics method for backscatter computations of complicated objects

The backscatter computation of complicated objects is carried by the physical optics (PO) method, known as the vector Kirchoff approximation. The object is described by a geometrical model using flat plates (panels). These panels can be nonperfectly conducting and multilayered. The PO solution for the scattering matrix of a single multilayered panel is evaluated in detail using the Fresnel reflection coefficients. An example of the computed reflection coefficient of a two-layered medium is presented. The phase integral of the PO method is solved analytically. The hidden-surface problem is discussed, and the procedure for the treatment of doubly reflecting panels is described. For an ideal conducting cube with additional surfaces that generate shadow and double-reflection effects, the computed radar cross section (RCS) is compared with measurements. Computational results of the RCS for nonperfectly conducting panels are given