3D GPR characterization of buried metallic and plastic tanks using time-reversal processing technique

This work presents a 3D GPR characterization of metallic and plastic buried tanks using the Time-Reversal (TR) technique. Geometry estimation of buried objects is very useful in many studies (e.g., archeology and engineering) and the GPR method can yield optimal results. In this work, we applied the TR technique to recover the geometry of buried tanks at the Shallow Geophysics Controlled Site 1, located in University of São Paulo. Four targets were chosen, two 200 L metallic tanks horizontally and vertically located at different depths and two vertical 100 L plastic tanks filled with different fluids. The TR technique uses the invariance property of the wave equation to generate images of targets in many applications (geoscience, meteorology, medicine, sound quality, etc.). This invariance property allowed modelling electromagnetic (EM) wave propagation using real data signals reversed in time as the source, focusing the energy on the target region and recovering its geometry. The modelling process applied the Finite Difference Time Domain (FDTD) approximation. The 3D geometry obtained with the TR technique was analyzed. The results showed that in some cases, particularly the plastic tanks, the TR obtained good geometry recovery.