Interpretation of multifrequency complex resistivity data for a layered Earth model

A method is proposed for interpreting data obtained by measuring mutual impedances of dipole-dipole configurations on the surface of a layered Earth. Such data are assumed to be available over a sufficiently broad band of temporal frequencies and dipoles interspacing. For a given grounded transmitting dipole, two receiving grounded dipoles of selected different orientations are used. The electromagnetic circuit coupling is effectively cancelled at any given frequency by appropriate Bessel transform operation on the measured complex impedances versus spacing. The next step is to infer the complex resistivities of the Earth's layers at each frequency. From such inferred data at a sufficient number of spot frequencies, the dispersive behavior of the resistivity of each layer is deduced. This proposed procedure is demonstrated by applying it to computer-simulated data on a two-layer Earth with encouraging results. >