Conductivity-depth transform of GEOTEM data

Abstract

A conductivity-depth transform (CDT) of airborne transient electromagnetic (EM) data generates approximate sections and maps of the subsurface electrical conductivity variations. The resulting products have instrumentation parameters such as the transmitter waveform removed and can be directly integrated with other information from the survey area. Although approximate, the conductivity depth transform has a number of advantages over an exact inversion method. These are illustrated with two examples: a groundwater salinity study in Australia and a survey over the Bushman mineral deposit in Botswana.