Fast Computation of Wideband RCS of Electrically Large Targets Modeled with NURBS Surfaces
NURBS曲面建模的电大目标的宽带RCS快速计算

The Physical Optics (PO) algorithm is utilized to compute the transient scattering response and wideband Radar Cross Section (RCS) of electrically large targets modeled with NonUniform Rational B-Spline (NURBS) surfaces. The formula for the time-domain scattered field is obtained with an inverse Fourier transform, which contains a convolution product. The time-domain PO integral is also derived with the inverse Fourier transform. In order to avoid the utilization of numerical integrations, the NURBS surfaces are discretized into small triangular facets, and Radon transform is introduced to obtain closed-form expressions for the time-domain and frequency-domain PO integrals. The improved z-buffer technique is used in the judgement and elimination of shadows for the sake of acceleration. The wideband RCS is obtained with the Fast Fourier Transform (FFT). The RCS of several targets is calculated under Gaussian-pulse plane wave incidence. Results show that the proposed method has a high accuracy and is faster than the traditional Time-Domain Physical Optics (TDPO).