A Fast and Efficient Method for the Composite Scattering of a Coated Object Above 3D Random Rough Surfaces

This paper presents a fast and efficient method that combines physical optics with physical optics to solve the composite scattering problem of a coated object above 3-D random rough surfaces. The object coated with lossy electric or magnetic radar absorbing materials is modeled as a stratified structure, and 3-D random rough surfaces are generated using Monte Carlo method with Gaussian spectrum. The proposed method utilizes fast and efficient physical optics as a solution for the coated object and the underlying random rough surface. Then a reradiation physical optics method based on Huyghens' principle is used as a solution for coupling scattering between the coated object and the underlying rough surface. The proposed method is numerically validated by comparing it with the commercial software FEKO and a multihybrid Kirchhoff approximation with the hybrid finite element-boundary integral algorithm. Runtime and memory consumption are also compared. Our method is found to reduce considerable time and memory while maintaining sufficient accuracy. The difference scattering radar cross section of a coated sphere above a 3-D perfectly electric conductor rough surface is numerically simulated. Furthermore, the dependence of difference scattering characteristic on the object coating parameters and the underlying rough surface parameters under different polarizations is discussed.