On the Spatial Resolution of UAV-Mounted DLGPR Imaging Systems

The integration of Ground Penetrating Radar (GPR) systems on board Unmanned Aerial Vehicles (UAVs) has experienced an important and rapid growth in the last few years. In contrast to conventional GPR systems (which usually function in ground-coupled mode), UAV-mounted GPR systems operate at a significant distance from the soil surface. Among other differences, the air-launched operation implies that the electromagnetic waves propagate through an inhomogeneous medium. This must be taken into account in the imaging algorithm to retrieve a well-focused radar image. Associated to this issue, in this contribution the spatial resolution of UAV-mounted down-looking GPR systems is studied. The analysis conducted shows that in the cross-range direction the spatial resolution equation used for homogeneous media is not applicable. In addition, results demonstrate that the cross-range resolution barely changes with the soil permittivity.