Comparison of a DC Integral Solution with a 3D EM Solution of the Magnetometric Resistivity Problem

Abstract

We have completed three-dimensional electro-magnetic (EM) modelling to verify the applicability of a direct current (DC) forward modelling solution for interpreting data collected by an experimental electrical resistivity tomography/magnetometric resistivity (ERT/MMR) system. Comparison of the EM solution to the static solution defines the range of environments where the zero frequency solution is applicable. The DC algorithm was determined to apply to a wide range of target resistivities (1´108 ohm-m ? 10 ohm-m) for operating frequencies up to 8kHz. However, magnetically permeable targets result in inaccurate interpretation and inversion results.