Numerical comparisons of short-pulse scattering models for rough surfaces

This paper provides a detailed numerical comparison between two frequency-domain rough-surface scattering models for the reconstruction of a short carrier-free pulse in the time domain. The two scattering models are a Space-Harmonic Model (SHM) and a Full-Wave Model (FWM), both of which assume a sinusoidally corrugated scatterer. To facilitate a time-domain comparison of the scattering algorithms, a Fourier series method is used to sum the scattered harmonics of the incident pulse. Several graphical comparisons are presented for backscattering of a train of square pulses which has been band limited to correspond to an X-band short pulse. The respective algorithmic difficulties and relative computational efficiencies are also briefly discussed. The computational results indicate that at moderate roughness and small incidence angles, the SHM and the FWM agree quite closely. The omission, however, of multiple scattering in the FWM formulation is seen to limit the effectiveness of the FWM for large scattering angles in combination with moderately rough surfaces.