Poster: Improved Methods for Detection and Classification of UXO Using Broadband Transient Electromagnetic Techniques
Donald D. Snyder III, Snyder Geoscience, Inc.;
Scott C. MacInnes*, Kenneth L. Zonge, Jennifer L. Hare*, Zonge Engineering and Research Organization, Inc., Tucson, Arizona;
Mary M. Poulton, Department of Mining and Geological Engineering, University of Arizona, Tucson, Arizona
Poster Series – [pdf] TEMposterA TEMposterB TEMposterC
Panel A: NanoTEM® – A System for Fast Multi-Channel TEM Data Acquisition
Panel B: Static TEM Antenna Array; TEM Data Reduction and Parameterization
Panel C: UXO Classification
High Power TEM Transmitter — Background
Since the late 1950′s, airborne TEM systems have been highly successful in finding mineral deposits and in mapping geology. These transmitters drive the transmitter loop with bipolar current pulses with a half sine wave shape. Conventional TEM systems transmit a series of long bipolar current
Two current waveforms are illustrated below in Figure 1 (left panel). Most ground-based TEM systems use a transmitter waveform such as that shown in red; airborne TEM systems typically use a half-sine pulse waveform in order to generate the higher moments necessary for airborne operations (blue curve). These two current waveforms produce secondary transients with different characteristics. The time derivative of the current shown in the right panel of Figure 1, for example, drives induction EM. Equally important, however, is the fact that the peak transmitter moment (i.e., turns x Area x Current) for the half-sine waveform is usually much higher than the moments generated with conventional transmitter waveforms.
Can a TEM system driven by a half-sine pulse type transmitter improve UXO detection? With SERDP funding, Zonge Engineering is conducting research to determine the answer.