Poster

[GP-P-04] Spectral analysis of reflected waves in ground penetrating radar signals

*Fuka Yamamoto¹, Yuki Fujiyasu¹, Kazuhei Miwa¹, Tada-nori Goto¹ (1. Graduate School of Science, University of Hyogo (Japan))

Ground penetrating radar (GPR), a non-destructive survey, is known to have higher resolution than other shallow geophysical surveys. Electromagnetic (EM) waves transmitted from the GPR system on the surface are reflected by the buried targets, which have different EM properties. The GPR is widely used in the fields of civil engineering and the environment. It is also effective in inspections of food, harvest, human body, and so on. However, with a simple GPR system, it is difficult to identify the substance of the reflector. Furthermore, in the case of a thin reflector, the reflected waves on the upper and lower surfaces of the reflector overlap and are hard to be separated. In this study, we focused on the spectral analysis of reflected waves to obtain the electrical properties of such thin reflectors. Here, a numerical simulation based on the finite difference method (FDTD) was performed. We carefully confirm the accuracy of numerical calculation by FDTD, then we focused on the spectrum peaks of the reflected wave. It was clarified a resonance phenomenon caused by the interference of the reflected waves within the buried object. Such phenomenon allows us to detect thin buried objects. It was also found that the spectral analysis is effective to extract the information of electrical conductivity of the reflector. This experiment assumed a paired GPR antennas without the wide-angle survey; therefore, a simplified system can tell us EM properties of the buried objects.