Two-Dimensional Imaging Of Transient Electromagnetic Soundings

Transient electromagnetic (TEM) soundings have been used extensively in geophysical<br>investigations in connection with environmental problems (Christensen and Sørensen 1994, 1995).<br>Within the geophysical community there is a growing realization that dense measurements<br>over large areas are needed to produce the reliability and detail demanded by the severity of many<br>of the problems addressed in environmental geophysics (Sørensen et al 1995, Sørensen 1996).<br>This calls for new efficient methods of data collection and fast interpretation procedures.<br>Consequently much interest has been directed towards rapid approximate interpretation<br>algorithms - imaging procedures - which will allow a quick overview of the data collected and<br>provide good starting models for rigorous, iterative inversion procedures.<br>A number of imaging methods for transient electromagnetic soundings have been suggested<br>based on the variation of the diffusion velocity with conductivity, e.g. Eaton and Hohmann (1989).