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Theoretical Fundaments to Obtain Complex Permittivity and Resistivity in CR Method
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 25th European Meeting of Environmental and Engineering Geophysics, Sep 2019, Volume 2019, p.1 - 5
Abstract
The resistive capacitive contact (CR) method is a non-intrusive geophysical technique that allows to characterize the subsoil, by means of electrical images. There are several models that interpret how the electromagnetic signal propagates in terms of the conductivity and polarization of the charges under the action of an electric field. In general, most of the works focus on the phenomenon of polarization. When a time-varying electric field is applied on a surface with a sufficiently high frequency for there to be a considerable relaxation time, not only a complex susceptibility but also a complex conductivity are generated and therefore, a complex resistivity. The purpose of this work is to analyze the behavior of the electromagnetic signal on a soil, with relatively high frequencies, and to link the complex conductivity and resistivity through the tangent of losses, as a function of a scale factor and a phase shift between the emitted and received signal. Through an adequate description of the physical principles involved, a theoretical formulation will be developed. It could be obtain through experimentally measuring the amplitudes and the phase shift, both the usual information of the apparent resistivity of the subsoil, and also information about its apparent permittivity.