TEM Models for a Conductive Host and Filament Migration

Abstract

Simple planar filaments can be used to provide a reasonable approximation to compound TEM eddy current decay systems. An optimum solution can be found using inversion theory to constrain the location and physical dimensions of these filaments in order to duplicate any spatial anomalies observed with fixed loop surveys. Multiple filament solutions are possible for any traverse using different windows in the total decay curve. Any systematic migration or progression in the results as a function of time can provide an indication of target or host configuration. Filament tracking techniques are developed here to provide a basis for data stripping designed to isolate a target response from the effects of highly conductive host materials. The results can provide for more complex geological constraints in place of a simple half-space model.