High Resolution Subsurface 3D SAR Imaging Using Robotic Bi-Static Transceivers

In this paper, a novel subsurface imaging technique for fast and high-resolution imaging of buried targets and subsurface features is introduced. The method employs synthetic aperture (SAR) technique to coherently process data collected at different locations within the imaging area and form a large 2D synthetic aperture to achieve high lateral resolution using small size antennas, eliminating the need for large antenna arrays required in high-resolution conventional ground penetrating radar (GPR) systems. The method only requires a pair of a transmitter and a moving receiver in a bi-static configuration to sample scattered fields from the ground to create 3D image of the subsurface environment. The small size of a special antenna for this system enables mounting of transceivers on robots or drones for autonomous data collection. Simulation and measurement results show that unlike GPR systems that require time consuming process of sampling the scattered fields on a grid, the new method requires a small number of samples on a circle to provide image of subsurface features within the entire circular area.