Frequency Domain and Time Domain Analysis of the Transient Field Radiated by GPR Antenna

The paper reviews the frequency domain and time domain analysis of transient electric field generated by the ground penetrating radar (GPR) dipole antenna radiating above a lossy ground. The frequency domain model is based on the space-frequency Pockiington's integro-differential equation and related field formulas, while the related transient response is obtained by means of the Inverse Fast Fourier Transform (IFFT). The direct time domain approach deals with the space-time Hallen integral equation and related field formulas. The numerical solution of Pockiington and Hallen equation, respectively, is carried out via the Galerkin-Bubnov Indirect Boundary Element Method (GB-IBEM). The effects of the two-media interface are taken into account via the corresponding space-frequency and space-time reflection/transmission coefficients. Some illustrative computational examples for the transient electric field reflected from interface and the transient field transmitted through the ground are presented. The numerical results obtained by different approaches are in a satisfactory agreement.