A Simple Correction to the Apparent Conductivity from Surface Magnetic Dipole Data

Abstract

 A method to improve the determination of apparent conductivities from near-surface electromagnetic dipole data should be simple and easy to implement and use in the field. With this objective, we present a simple correction to the apparent resistivity from surface magnetic dipole data. In contrast with the traditional approach that uses a truncated series to approximate the fields, the proposed method calculates the apparent conductivity by solving a minimization problem using the complete homogeneous half-space analytical solutions for the magnetic field of the dipole sources. In comparison with previous approaches to improve apparent conductivity estimation, this is an extremely simple solution, easily implemented and demanding almost negligible computer time and memory. To illustrate the method, applications to synthetic 2D data and real data are presented. The results show that the method can improve the responses of conductive zones which are difficult to perceive in the raw field data.