An Effective Method for Borehole Imaging of Buried Tunnels

Figure 3

LSM imaging of the tunnel in the cross-hole measurement setup. Normalized logarithmic plot of the LSM indicator, binarized LSM indicator with threshold 0.75, and binarized three-dimensional LSM indicator in the whole region: (a)–(c) vertical dipoles and (d)–(f) horizontal dipoles.

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