Optimal antenna of ground penetrating radar for depicting the debris thickness and structure of the Koxkar Glacier, Tianshan, China

Abstract

We use multi-frequency ground penetrating radar (GPR) to detect and map debris thickness and shallow layer structure of buried ice-body under debris-covered. The basis analysis is depend on mainly (1) the stacking wave velocity in a common mid-point (CMP) survey, (2) the ratio of attenuation of an electromagnetic wave passing through different media, and (3) the vertical resolu- tion. Through a series of analysis, it was found that the optimal average velocity in the shallow layer (0-4 m) is 0.06 m/ns. Images obtained with antennas having different frequencies have different cha- racteristics; i.e., the 50 MHz antenna provides much worse vertical resolution than the 200 and 100 MHz antennas (90 and 160 ns, respectively) and the performance of the 200 MHz antenna for a debris-covered glacier is best. This study provides the basis for accurate analysis of the structure and thickness of the debris layer in the zone of ablation of a debris-covered glacier, this study also provides a reference for research into the formation mechanism and estimation of the ice volume of glacier