A full electromagnetic simulation of a ground penetrating radar: theory and experiment

Ground penetrating radars (GPRs) are electromagnetic systems used for detecting buried objects in the earth. The electromagnetic analysis of GPRs is complicated by the close proximity of the transmitting and receiving antennas, the surface of the earth and the buried object. Because of this close proximity, separate models for each of the elements when isolated, e.g., one of the antennas in free space, often cannot be combined to analyze the complete system. Other complicating factors are the dissipation and dispersion for the electromagnetic signals in the earth and the clutter caused by buried rocks, roots, etc. A full electromagnetic simulation of a GPR is described which uses the finite-difference time-domain (FDTD) numerical method. Results from the simulation are compared with measurements previously made on a one-third size, scale model for the GPR.