RCS computation of airplane using parabolic equation

The accurate analysis of scattering from objects with dimensions large compared to the wavelength using rigorous methods (finite element, FDTD, method of moments) with a personal computer is almost impractical. In asymptotic methods, physical optics ( PO), geometrical theory of diffraction (GTD), the accurate modeling of the object's boundary is too cumbersome. The parabolic equation method gives accurate results in calculation of scattering from objects with dimensions ranging from one to tens of wavelengths. Solving parabolic equation with the marching method needs limited computer storage even for scattering calculations of large targets. In this paper, first the calculation procedure of radar cross section using parabolic equation in three dimension is studied and the necessary equations are derived. In order to show the validity of the parabolic equation, the RCS of a conducting sphere is calculated and the results are compared with analytic results. The airplane RCS has been computed by using a staircase model in the parabolic equation and the results are compared with physical optics results.