A Modified Model for Quasi-Monostatic Ground Penetrating Radar

Abstract

Ground penetrating radar (GPR) is a widely used nondestructive testing tool. This letter presents a modified model for quasi-monostatic configured GPRs. In this model, the antenna effects are represented by a set of linear transfer functions and the GPR responses of the layered media are modelled by 3-D Green's functions. In order to obtain sufficient accuracy, the proposed model includes a special effect such that a part of the electromagnetic wave, propagating directly from the transmitting antenna to the receiving antenna, is reflected outside as a new transmitting signal. The experimental results of the full-waveform inversion have demonstrated that considering this special effect in the quasi-monostatic model is effective for improving accuracy. Although both monostatic and quasi-monostatic GPRs can be accurately modelled for full-waveform inversion, the results of the experiment performing inversion of a three-layer media with low permittivity contrast, proved that the latter can achieve better performance due to its intrinsic higher signal-to-noise ratio (SNR).