On Accuracy of Discrete Ray Tracing Method in Comparison with Rigorous Solutions

This paper is concerned with a numerical analysis of electromagnetic wave scattering by a conducting cylinder or by a conducting half-plane to check the accuracy of the numerical results computed by discrete ray tracing method (DRTM). In case of a cylinder, its boundary is approximated in terms of piecewise-linear plates, and source and image rays are searched based on the approximated profile. The total scattered fields are given by superposing each scattered field related to each plate which is computed by use of the source and image diffraction coefficients obtained by the Fresnel function. In case of a half-plane, the total scattered fields are computed rigorously by using the Fresnel function. In the former case, numerical results are compared with the rigorous solutions given by use of the Bessel and Hankel functions. In the latter case, numerical computations are performed to check the effect of diffraction points on the field distributions in shadow region. It is demonstrated that DRTM provides us a good convergence.