An empirical procedure for removal of polarisation effects observed in TEM field data

Abstract

Research has demonstrated that negative TEM voltages observed in coincident loop or in-loop survey data are due to induced polarisation effects. These effects have approximate negative exponential decays which are most often observed in late time data. By removing the inductive half-space and thin layer responses, and then matching and removing the negative exponential due to polarisation effects from affected readings, it is possible to provide a better presentation of data and unveil anomalous conductive responses which would otherwise have been overlooked.