Combining F-K Filter with Minimum Entropy Stolt Migration Algorithm for Subsurface Object Imaging and Background Permittivity Estimation

Determination of background permittivity and removing of the direct wave is one of the main problems in data processing on Ground Penetrating Radar. The interference of direct wave will greatly affect the accuracy and the resolution of GPR imaging. We propose an f-k filtering approach for the solution, which use a difference of an apparent velocity between a direct wave and a reflection from a target. Besides, a Stolt migration algorithm combined F-K filter with minimum entropy technique is proposed to improve the focus effect of the radar image and realize the precise inversion of background relative permittivity. Synthetic data generated by FDTD have been used to test the improved migration algorithm, and the results show that the presented algorithm can achieve comparative results produced by windowed filter based Stolt migration algorithm.