Evaluating the Properties of Millimeter- and THz Wave Scattering from Common Rough Surfaces

A simple numerical approach is presented to estimate rough surface scattering. We measure the roughness parameters of rough surfaces and then import them into a 2D model to compute the scattered fields under various surface illuminations. The validity of this approach is demonstrated by comparing the simulation results with measurements. Besides, we use the 2D model to simulate rough surfaces of a wide range of roughness parameters and perform a qualitative analysis on the scattering patterns. We show that, for most common building materials of moderate roughness, increasing the root-mean-square height of the rough surface reduces the maximum reflection and increases diffuse scattering. On the other hand, increasing the correlation length of the rough surface will lead to lower maximum reflection and diffuse scattering.