Quantifying GPR transient waveforms in the intermediate zone

In this paper we examine the transient electromagnetic field variation around dipole antennas placed on the surface of a half-space. To achieve this we employ three-dimensional (3D) finite-difference time-domain (FDTD) numerical modelling. We have previously shown how antenna height, shielding and ground properties impact the directionality and energy flow. Here, we report how the transient fields around a dipole change their amplitude, shape and frequency content. Further, we demonstrate how the aforementioned attributes change as we move away from the source.