Pre-stack Reverse-time Migration Applied to Ground Penetrate Radar Synthetic Data

Reverse-time migration (RTM) is used to handle complex velocity models with steeply dipping interfaces and dramatic variations in transverse velocity, which promises better imaging results compared with traditional migration method such as Kirchhoff migration algorithm. RTM has been increasingly used in oil and gas seismic exploration. Based on the similarity of kinematics and dynamics between electromagnetic wave and elastic wave, we apply pre-stack RTM method to process Ground Penetrating Radar (GPR) data in this paper. Finite-difference time domain (FDTD) numerical method is used to simulate the electromagnetic wave propagation including forward and backward extrapolation, the cross-correlation imaging condition is used to obtain the final image. Evaluation is in the context of a complex geological structure model; the Gaussian random roughness surface is introduced to represent the underground layer interface; common offset radar data and multi-shot wide-angle reflection and refraction (WARR) radar data are synthesized. The migration results from electromagnetic wave pre-stack RTM show excellent coincidence with the true model.