Numerical simulation of GPR via Leapfrog ADI-FDTD

Abstract

Numerical simulation of Ground-penetrating radar (GPR) is the basis for interpretating and inverting geological information from real GPR measured data. However, the current matured finite difference time domain (FDTD) numerical simulation technique has drawbacks such as strict time step limitation due to Courant Friedrich Lewy (CFL) condition and long computation time. As an improve method of FDTD, the alternating direction implicit FDTD (ADI-FDTD) numerical simulation technique, although stable and not limited by CFL condition, occupies a large amount of memory and has low computational efficiency. Therefore, we developed a GPR numerical simulation method based on the Leapfrog ADI-FDTD technique. The calculation results of this method are unconditionally stable, and its time step is not limited by CFL condition. In addition, in response to address the problem of slow numerical simulation speed cause by traditional sequential simulation, we also introduced Open multi-processing (OpenMP) technology to improve the serial simulation of sequential calculation into parallel simulation of multi-channel simultaneous computation in shared memory, further improving the computational efficiency of GPR numerical simulation. The numerical simulation results of homogeneous model, high contrast boundary model, three-layer geological model and slightly more complex geological model show that the proposed method effectively combines the advantages of Leapfrog ADI-FDTD and OpenMP parallel computing to achieve GPR numerical simulation quickly.