Time Domain Electromagnetic Migration In Inel Rwmc Cold Test Pit Characterization

The main task of the conducted research was interpretation of time domain<br>electromagnetic (TDEM) data set acquired at the Cold Test Pit within the<br>Radioactive Waste Management Complex (RWMC) at the Idaho National<br>Engineering Laboratory (INEL) using Electromagnetic Migration method.<br>There were several publications dedicated to the development of simple<br>and fast inversion technique for the processing of transient electromagnetic<br>data (Eaton and Hohman, 1989; Macnae and Lamogntagne, 1987;<br>Barnet, 1984). Majority of these papers have been based on equating the<br>transient response, measured at the surface of the Earth, to the EM field of<br>current filament images of the source (Nabighian, 1979).<br>In this paper we have developed and used a different approach to processing<br>of transient data, based on downward extrapolation in reverse time.<br>We call this method the time domain electromagnetic migration<br>(Zhdanov et al., 1994). The technique has been developed for the transformation<br>of the transient electromagnetic migration field into resistivity<br>images of the vertical cross-section. We discuss the principles of electromagnetic<br>migration and resistivity imaging and present the results of application<br>of the method for the imaging of TDEM data set from the RWMC.