Underground Cavity Imaging Based on PSTD Reverse Time Migration Algorithm

In order to solve the problem of low resolution and low imaging efficiency of GPR imaging of underground holes, the pseudo-spectrum time domain (PSTD) method and normalized cross-correlation imaging conditions are proposed to be used in the reverse time migration (RTM) imaging algorithmin this paper. Aiming at the problem of low resolution of underground cavity imaging, normalized cross-correlation imaging conditions are used to improve the imaging results. The results show that the reverse-time migration profile based on the normalized cross-correlation imaging conditions can more clearly reflect the deep information of the cavity, and the shape information of the cavity can be determined.