Characterization of local 3D rough surfaces using UWB near-range phase-based GPR signatures from wide-beamwidth antennas

This paper pertains to further investigations on using an ultra wideband (UWB) multistatic coherent ground-penetrating radar (GPR) technique for precise profiling of the rough surfaces in three-dimensional space. The method is essentially based on the phase processing of the sliced layers of three-dimensional rough surfaces with multiple sub-frequency bands. The data acquired in the near range by a UWB stepped-frequency continuous-wave GPR with wide-beam antennas over a compound surface are used to verify the method. It was found that in the near-range measurements the range side-lobe interference effects and the reflections from the measurement surroundings sometimes have a significant influence on the target phase and amplitude responses, and consequently degrade the localization of the targets. The present study on this issue shows that within the ultra wideband, some sub-frequency bands are less sensitive to the measurement surroundings, but still sensitive to the target area. With the selected sub-frequency bands the image of the compound surface reconstructed in the surface height domain shows good agreement with the practical geometry of the rough surfaces.