Measurement and Analysis of Bidirectional Reflectance Distribution Function of Building Wall

With the development of
$5\mathrm{G}$
, the location of base stations is related to the electromagnetic wave scattering with the surface of objects, especially the building walls in cities. In this study, the building wall is simply modeled as a two-dimensional plane surface. Since the roughness of the building wall is relatively small, the specular reflection is the main component of the scattering wave. The bidirectional reflectance distribution function (BRDF) of building walls is approximated as the Fresnel reflection coefficients. Then, a field measurement system, called FUSAR-Rail-S, is established to measure the scattering of the building wall. In the measurement, two different walls are used to analyze the roughness effect on the scattering coefficient. A comparison of the measurement result with the Fresnel reflection coefficients shows that they are in good agreement in most angles. Within a certain angle range, the reflection coefficients increase when the incident angle becomes larger. In addition, the reflection coefficients of the smaller roughness wall are larger.