Diffraction from multiple ridges: Comparing three-and two-dimensional results

Diffractions from multiple-wedge structures are important in many wireless communications environments. For irregular terrain, the diffraction from ridges are commonly calculated using a two-dimensional height profile. Due to the fact that such a profile does not have the information about the slope and orientation of the ridges, and the interior angle is often incorrectly represented, three dimensional method is needed to improve the accuracy of the diffracted field. Furthermore, the ray paths determined using the height profile is in general wrong because they are not the least-time paths. In this paper we compare the path loss differences between the two- and three-dimensional methods.