Fast processing of resistivity sounding measurements in N-layer soil

This paper presents a new method and derives the theoretical equations for calculation of the apparent resistivity standard curves of horizontally multilayered models. For known earth parameters, the apparent resistivity distribution can be computed efficiently by this method. The profile of the apparent resistivity calculated with Schlumberger electrode arrangement for an arbitrary number of layers is presented. However, to prove the reliability of the present method, the apparent resistivity of given three to five layer models is calculated for the Wenner array using existing methods and the presented one. Also, this paper uses an inversion method to find the electrical grounding parameters of an N-layered earth (resistivities and thicknesses) corresponding to a specific mathematical model. Parameters estimation is carried out in such a way as to get a fitting between the set of resistivity values measured by means of Schlumberger´s method, and those calculated from the mathematical model using such parameters.