Millimetre-wave scattering from one-dimensional surfaces of different surface correlation functions

High spectral components contained in surfaces with non-Gaussian correlation functions are believed to increase the magnitude of backscattering enhancement. In this paper, we present experimental and numerical studies of bistatic scattering from one-dimensional surfaces with Gaussian and power-law roughness spectral densities. Rough surfaces with an rms height of σ = 3 mm and correlation lengths of l = 3, 6 and 9 mm were fabricated and measured with a millimetre-wave scatterometer. The corresponding rms slopes were m = 1.41, 0.707 and 0.47, respectively. Both experimental and numerical simulation data show that surfaces obeying the power-law roughness spectral density have stronger backscattering enhancement than those with a Gaussian roughness spectral density for the same surface rms slope. Good agreement between experiments and numerical simulations was obtained. In addition, the numerical studies were conducted to obtain the scattering characteristics of surfaces with Gaussian and power-law roughness spectral densities for different rms heights, correlation lengths, and rms slopes.