Detection and identification of a tunnel by iterative inversion from cross-borehole CW measurements

Iterative multiparameter optimization is applied to find underground geophy sical structural parameters including an isolated penetrable target such as the air tunnel. 11 physical parameters such as relative permittivities, an d the conductivities of the background, the tunnel, and the fractured zone, their sizes and locations, and the measuring borehole distance are found f rom the in situ measured data by using the hybrid optimization algorithm co mbining the Levenberg-Marquardt and the genetic algorithms. (C) 1999 John W iley & Sons, Inc.