“…In Reflex-Win software, modeling results are obtained using the finite difference time domain (FDTD) method. The FDTD technique has been widely used to analyze EM phenomena (Tirkas & Demarest, 1991;Jurgens et al, 1992;Luebbers, Steich, & Kunz, 1993;Huang, 1996;Chen & Huang, 1998;Bergmann, Robertsson, & Holliger, 1998;Oguz & Gurel, 2001). This technique is used for accurate modeling near field time-domain GPR and it can also model antennas and targets with complex shapes with virtually no additional computational effort (Roberts & Daniels, 1997).…”