Research On And Implementation Of Electromagnetic Modeling Method Based On Physical Optics

On account of the huge computation problem of electrically large complex targets scattering, this paper mainly discusses the realization of the Physical Optics (PO) electromagnetic modeling. The simulation of the EM modeling includes two parts, geometrical modeling and electromagnetic (EM) calculation.Geometrical modeling is a process of storing target models as some data structures. Geometrical info, topology info and EM info are required for EM calculation. And allowing for the characteristics of every modeling method, boundary representation as the form of gridding is adopted to model the targets. At the same time, ray-tracing method is introduced to consider the contribution of multi-scattering. Z-buffer algorithm is proposed to distinguish visible facets, and 3DDDA algorithm is suggested to consider ray-tracing.In the part of EM calculation, three principal scattering mechanisms, including facet contribution, edge diffraction and multi-scattering, are studied in the dissertation. Physical Optics is adopted to calculate the scattering of facets. Allowing for the characteristics of modeling, a simplified form is derived under condition of polygon, not including integral. ILDC is introduced to calculate the contribution of edge diffraction. And also a simplified form is reached for planar structure, not including dyadic. In order to improve the accuracy of calculation, multi-scattering is discussed, based on the two former contributions and ray-tracing method. Geometrical Optics (GO) and PO are used to calculate the multi-reflection between facets and facets, and a combination of GO and ILDC is used to calculate the interaction of edges and facets. The simulation results testify the validity of the above methods.After integrating the two parts, a primary version of the software system is obtained. It can carry out modeling operations according to the requirement of users, and can calculate RCS of modeled targets. Functions of the system are introduced in the last part of the dissertation,...