A Forward Approach to Establish Parametric Scattering Center Model for Dielectric-PEC Composite Targets

In this article, a forward approach is proposed to establish the 3-D scattering center (SC) model for dielectric-perfect electrically conducting (PEC) composite targets (including nested targets). First, various-order SCs are separated from computer-aided design (CAD) models by ray tracing and clustering technology applicable for the dielectric-PEC composite target; in particular, the multiple refraction-containing coupling scattering mechanisms are involved in the scattering of nested targets. Furthermore, a set of forward methods (FMs) is developed to determine the parameters of 3-D attribute SCs, including amplitude, frequency factor, position, and length. The method addresses the challenge of deriving the model parameters of multi-order refraction-containing coupling SCs generated by multiple bounces and complex propagation media. Finally, this approach is validated by establishing the parametric model of several composite targets (including nested targets), and the synthetic aperture radar (SAR) image reconstructed by the model behaves a good agreement with the result of the RLGO algorithm in FEKO. This approach provides a clear physical image of the SC formation process. It helps construct a target feature database and enables radar target recognition via image-domain characteristics and physically relevant model parameters.