Improved time-domain physical optics for transient scattering analysis of electrically large conducting targets

An improved time-domain physical optics model (TDPO) is proposed to determine the transient response of electromagnetic scattering of electrically large conducting targets modelled with triangular facets. A formula for the improved TDPO is derived, in which a time-domain convolution product between the incident plane wave and the time-domain physical optics (PO) integral is included. The time-domain PO integral is evaluated with a closed-form expression based on a Radon transform interpretation. Since the tedious and time-consuming numerical integration utilised in the conventional TDPO is avoided, the improved TDPO has a significant superiority over the conventional TDPO in terms of speed and stability, which is of great value to the transient response analysis of electrically large targets. Numerical results demonstrate the efficacy of the new method.