| Novel Methods of Detecting Buried Explosive Devices |
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| Oak Ridge National Laboratory, Oak Ridge, Tennessee | |
| Sep 30 2007 | |
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Advertisement: Another novel method involves the use of swept acoustic resonance by means of an apparatus that would include a transmitting and a receiving ultrasonic transducer placed in contact with the ground. This apparatus would be used in conjunction with a previously developed metal detector, which would be used to locate buried metal objects that may or may not be the metal components of landmines (most landmines contain at least some metal). The ultrasonic transducers would be placed on the surface at a small safe distance away from a location indicated by the metal detector, so that the surface projection of the detected metal object would lie between the transducers. The transmitting transducer would emit a train of acoustic pulses shaped to have energy concentrated in the frequency range of 5 to 50 kHz. The structural features of landmines have mechanical resonances in this frequency range. The output of the receiving transducer would be processed to develop a transfer function that would exhibit a measurable characteristic in the presence of resonances associated with a landmine. A third novel method involves exploitation nuclear quadrupole resonance (NQR). The basic idea is to excite and detect NQR by means of a lowpower signal at a suitable radio frequency applied to a small induction coil placed near a suspected mine. Previous research has already shown that some explosive compounds have NQR signatures useful for detection: for example, trinitrotoluene (TNT) exhibits a response distributed over 12 spectral lines, of which the ones most appropriate for detection of mines lie in the frequency range from 836 to 870 kHz. A fourth novel method involves semiotic multi-sensor data fusion. The basic idea is to apply semiotic concepts (in contradistinction to older feature-vector-based pattern-recognition methods) to make the most effective use of data from multiple sensors in order to achieve both a high probability of detection and a low falsealarm rate. The approach to be taken in developing this method is not as well defined as are the approaches being followed for the other three methods. However, the mere fact that dogs can detect mines consistently by means that we do not yet understand can be taken as evidence that mines have detectable features. This work was done by S. W. Kercel, R. S. Burlage, D. R. Patek, and C. M. Smith of Oak Ridge National Laboratory and A. D. Hibbs and T. J. Rayner of Quantum Magnetics, Inc. Prev: All-Dielectric, Non-Electronic Radio-Receiver Front Ends Next: System for Imaging Turbulent Combustion Flows |
