Modelling of angular dispersion due to rough surface scattering for implementation in ray-tracing-based propagation prediction tools

This paper describes the modelling of scattering caused by irregular surfaces as a basis for im-plementation in ray-tracing methods. An approach is presented in a first attempt to model the dispersive effects, caused by scattering on surfaces which have "random" irregularities, directly at the receiver. The method is based on assigning an effective stochastic roughness to a specific surface. The scattering effects caused by the surface roughness include the combined effects of both the surface irregularities and changes in material properties. The possibility of including the model into a 3-D ray-tracer is outlined. The results of simulations and measurements show that the method can be used to model the dispersive effects of rough surface scattering in a manner similar to using the reflection reduction factor for Gaussian surfaces, except that the reduced power in the specular direction is distributed in the angular domain.