Numerical Analysis Of The Scattering Characteristics Of Rough Surface With Above Or Underneath Target

The electromagnetic scattering research of composited model including rough surface and target has a broad meaning, such as remote sensing and target detection. This paper analyzes the numerical method for one dimension composited models, such as forward and backward method (FBM), generalized forward and backward method (GFBM), propagation inside layer expansion (PILE) and spectral acceleration (SA). Besides, a new extended spectral acceleration method (ESA) is introduced to deal with the absorptive medium with more details. In this paper, ESA is verified to precisely deal with the electromagnetic scattering problems of composited models. Next, we have developed generalized minimum residual algorithm (GMRES) procedure right preconditioned with generalized forward and backward spectral acceleration method (GFBM-SA) to analyze the composited model, which the surface is connected with the target. Furthormore, the experimental data is proposed to show the different iterative characteristics of GMRES-RP and GFBM-SA. Meanwhile, combined with the proposed forward and backward extended spectral acceleration method (FBM-ESA), constucting a new preconditioning matrix, the GMRES-RP is introduced to deal with the composited model when the target is above or below the rough surface. The simulation data show the developed ESA method can manage the interaction between two points of surface with a low relative error below6e-3%when the length of surface is2048lamda and the dielectric constant of the absorbing medium is4+0. li. There is no need to use multilevel method to deal with large rough surface. And ESA is more flexible than SA for that the parameter selection is determined by the specific rough surface situation. Besides, a good accuracy is achieved in the calculation of the scattering coefficient of dielectric rough surface. The analysis of electromagnetic scattering of the composited models are based on the applicable and specific preconditioning matrix. The computational efficiency is largely improved compared to GFBM-SA, especially for TE polarization, in processing the composited model when the target is connected to rough surface. And the GMRES-RP can handle wider roughness range. Also the GMRES-RP, combined with forward and backward spectral acceleration method (FBM-SA) method, can handle the composited model, when the target is above or below the rough surface, accurately and effectively. From the achieved electromagnetic scattering coefficients, we know that the target below the rough surface can hence the backscattering coefficient.