HIGHER ORDER METHOD OF MOMENTS FOR BISTATIC SCATTERING FROM 2D PEC ROUGH SURFACE WITH GEOMETRIC MODELING BY NURBS SURFACE

The higher order method of moments (HMOM) has been proposed to calculate the bistatic scattering from two-dimensional (2D) perfectly electric conducting (PEC) rough surface in this paper. The electric field integral equation (EFIE) is solved through the HMOM with the hierarchical higher order basis functions which are the modified Legendre polynomials. The non-uniform rational B-spline (NURBS) surface is applied to model the plane surface related to the rough surface. Validity of this approach is shown by comparing the bistatic scattering coefficient (BSC) to that of lower order MOM (LMOM) with the Rao-Wilton-Glisson (RWG) or rooftop basis function. This approach has fewer segments in the parametric directions than the LMOM with rooftop basis, and is more efficient for the fewer unknowns and requires less memory than the LMOM with RWG basis. Properties of EM scattering from a 2D Gaussian rough surface are also exhibited and analyzed.