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Fig. 3
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Noticeable hyperbolas caused by subsurface rocks. The travel velocities of radar signal estimated by curve fitting from these hyperbolas are (1) 15.97 ± 0.48, (2) 15.63 ± 0.30, (3) 16.38 ± 0.30, (4) 17.08 ± 0.36, and (5) 16.50 ± 0.31 cm ns1.
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