Optimal antenna of ground penetrating radar for depicting the debris thickness and structure of the Koxkar Glacier, Tianshan, China
Zhen Wu, Shiqiang Zhang, Shiyin Liu
Journal of Earth Science ›› 2013, Vol. 24 ›› Issue (5) : 830-842.
Optimal antenna of ground penetrating radar for depicting the debris thickness and structure of the Koxkar Glacier, Tianshan, China
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 resolution. 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 characteristics; 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 covered by debris.
multi-frequency ground penetrating radar / antenna / comparative test / Koxkar Glacier / debris layer
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