An imaging of buried anomalies, using multi-sheet 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 sheet of conductance S₁ (x, y) and a buried sheet of conductance S₂ (x, y). The buried sheet is embedded at a depth d in a layered earth of conductivity σ(z). The σ(z), d and S₁ (x, y) are assumed to be known. We determine S₂(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 continuation of EM field from the earth’s surface onto the buried sheet. Employing synthetic data we demonstrate that the designed inversion scheme generates a reasonable image of the buried structure. The scheme is fast, since it doesn’t require any forward modelling.