Analysis of High-Frequency Electromagnetic Scattering by Complex Targets Using Dual Flat Facet Representation

It is usually difficult to cater for multiple scattering and shadowing in the application of high-frequency asymptotic methods for electromagnetic (EM) scattering since this involves complicated geometrical computation. Efficient techniques with the use of dual flat representation of the target geometry are proposed to overcome this drawback. The dual facet representation is formed by a set of small triangular facets and an additional set of relatively large triangular facets. The set of smaller facets is used for the EM analysis so that approximation can be adopted to avoid the complicated geometrical computation associated with multiple scattering and shadowing, and the set of larger facets is applied for the computation of line/facet interaction and geometrical reflection to achieve computational efficiency. Numerical results are presented to demonstrate the validity and efficiency of the present technique, and the effect of the facet size on the solution accuracy is discussed.