In situ microwave reflection coefficient measurements for smooth and rough exterior wall surfaces

Microwave reflection coefficient measurements at 1.9 GHz and 4.0 GHz are given for a variety of typical smooth and rough exterior building surfaces. The measurements are compared to theoretical Fresnel reflection coefficients using Gaussian rough surface scattering models when applicable. Individual multipaths are resolved temporally, using a spread spectrum sliding correlation system, and spatially, using directional antennas. The measurement test cases include walls made of limestone blocks, glass, and brick. The results indicate that the Fresnel reflection coefficients adequately describe the reflective properties of the glass and brick surfaces. The rough stone wall measurements are shown to be bounded by predictions for a smooth surface model and a Gaussian rough surface model.