Aperture Synthesis Method to Investigate on the Reflection Properties of Typical Road Surfaces

In this contribution, a millimeter wave FMCW (frequency modulated continuous wave) radar is utilized to investigate the surface reflection of an asphalt sample at 80 GHz. Since the reflection properties of such a rough surface usually strongly depend on the characteristics of the antenna (i.e. opening angle, spot on sample) that is used in the measurement, a more generalized approach is presented here. Based on the backprojection algorithm, the measurement data, obtained by a relatively undirected antenna, are used to infer the reflection properties for different antenna systems with other radiation patterns. Exemplary measurement results are presented in this paper, proving the suitability of the proposed method.