Finite element method GPR forward simulation in dispersive medium

In order to more accurately understand the propagation law of GPR (ground penetrating radar) wave in dispersive medium, the Fourier transform was adopted under the condition that relative dielectric constant in dispersive medium and frequency satisfied the Debye condition, and the wave equation of electromagnetic field was obtained in time domain based on the Maxwell equations. The wave equation of GPR electric field was taken as an example, and the 2-D finite element equation of GPR in dispersive medium was gotten by means of Galerkin finite element method. By combining transmitting absorbing boundary, the strong reflected wave on truncation boundary was effectively weakened and the reflected wave on truncation boundary was absorbed adequately. On the basis of the theory mentioned above, the program of its feasibility and effectiveness was tested by homogeneous and two-rounded models. The results show that compared with the modeling results of non-dispersive medium, the GPR wave in dispersive medium attenuates faster than that in non-dispersive medium, and the width of GPR wave in dispersive medium gets larger with the increase of the distance. Width of the reflected wave with the abnormal body in dispersive medium is larger than that of the reflected wave in non-dispersive medium.