A fast and accurate numerical approach for electromagnetic inversion

TL;DR

This paper introduces a rapid and precise numerical method for electromagnetic inversion that models layered earth conductivity using a novel integral approximation and applies optimization algorithms to interpret survey data.

Contribution

It presents a new splitting-based integral approximation method and a novel minimization approach for electromagnetic inversion in layered earth models.

Findings

The method achieves high accuracy in modeling electromagnetic fields.

It effectively estimates underground conductivity from survey data.

Numerical experiments confirm the technique's reliability.

Abstract

This paper deals with the solution of Maxwell's equations to model the electromagnetic fields in the case of a layered earth. The integrals involved in the solution are approximated by means of a novel approach based on the splitting of the reflection term. The inverse problem, consisting in the computation of the unknown underground conductivity distribution from a set of modeled magnetic field components, is also considered. Two optimization algorithms are applied, based on line- and global-search methods, and a new minimization approach is presented. Several EM surveys from the ground surface are simulated, considering the horizontal coplanar (HCP) and perpendicular (PRP) magnetic dipolar configurations. The numerical experiments, carried out for the study of river-levees integrity, allowed to estimate the errors associated to these kind of investigations, and confirm the reliability of the technique.