Limitations of Time-Reversal approach to buried object detection in the soil

In this paper, we present the preliminary study on Time-Reversal limitations in refocusing into the soil and conception of method for its improvement. Due to the soil nature, it is important for detection of buried objects to develop modern algorithms with high capabilities. Firstly, based on a data from geological database and a pedotransfer function, we estimate the dielectric constant of the soil, which was used to create an electromagnetic model of soil subsurface. Secondly, used mathematical description of waves propagation into inhomogeneous dispersive loss medium, we performed forward probing numerical simulation of waves propagation into the soil (using the finite-difference time-domain method). Special emphasis was placed on a faithful mapping the phenomenon of dispersion and energy distortion. Then, based on time-reversal foundation, we performed simulation with a time-reversed segment of the recorded signal in forward probing step. Results of both simulations are presented and discussed. On the basis of numerical experiments we proposed the concept of compensation for defocusing-inrange.