Comparison of Radar Imaging Configurations for the Characterization and Diagnosis of Roadways

This paper investigates and compares different imaging configurations for roadway inspection. Ground-penetrating radar is generally used to detect and characterize the vertical structure of the underground medium, whereas Off-Nadir Synthetic Aperture Radar can work both in back-scattering and forward-scattering modes. Back-scattering mode provides a capacity of discrimination in azimuth and range directions, while forward-scattering mode converts range resolution into vertical resolution. Vertical sampling is then used to realize tomography. 3D-focusing imaging of roadways is thus shown to be able to adequately and efficiently evaluate the underground structure.