AN IMAGING OF BURIED ANOMALIES, USING MULTISHEET INVERSION

The objective of this paper is to construct a stable inversion scheme to determine the conductance of a buried inhomogeneous layer masked by sedimentary cover. We employ a model which incorporates a surface she et of conductance S-1(x, y) and a buried sheet of conductance S-2(x, y ). The buried sheet is embedded at a depth d in a layered earth of con ductivity sigma(z). The sigma(z), d and S-1(x, y) are assumed to be kn own. We determine S-2(x, y) by inverting the monochromatic horizontal electromagnetic (EM) field measured at the earth's surface. To do this , we use Price's matching conditions at the sheets and a stable contin uation of EM field from the earth's surface onto the buried sheet. Emp loying synthetic data we demonstrate that the designed inversion schem e generates a reasonable image of the buried structure. The scheme is fast, since it doesn't require any forward modelling.