Radar multipath scattering from the composite model: Specular image modified model and ISAR imaging analysis

The theoretical implementation aspect of high‐frequency electromagnetic scattering prediction from the composite model is proposed in this work. First, the composite model is described and the multipath scattering prediction method (physical optics + equivalent edge currents + four‐path model) is formulated. Then, by introducing the concept of the specular image facet, a modification, named specular image modified four‐path model (SIMFPM), is developed to calculate the coupling scattering field between the electrically large three‐dimensional perfect electric conducting target and the dielectric rough surface. The proposed procedure makes preparation for the analysis of the multipath scattering effects on inverse synthetic aperture radar (ISAR) imaging in the final part. Numerical examples demonstrate the accuracy of the SIMFPM and present the multipath effects on the ISAR image.