Enhanced signal and auditory processing for landmine detection using EMI sensors

Although the ability of EMI sensors to detect landmines has improved significantly, false alarm rate reduction remains a challenging problem. However, experienced operators can often discriminate mines from metallic clutter with the aid of an audio transducer. The goal of this work is to optimize the presentation of information to the operator and to determine whether information as to the presence of metal can be co-presented with information regarding mine/non-mine belief. Traditionally, an energy calculation is provided to the sensor operator via a signal whose loudness and/or frequency is proportional to the energy of the received signal. This information codes information as to the amount of metal present. However, there is information in the unprocessed sensor signal that the operator could use to effect discrimination. We have experimentally investigated the perceptual dimensions that most effectively convey the information in a sensor response to a listener using simulated data. Results indicated that, consistent with the auditory warning literature, pulsed audio signals with a distinct harmonic pattern which rise in fundamental frequency can be used to provide information which provides better performance than simple single-frequency tones. Additionally, the data indicated that the amount of metal could be coded in the rising pitch of the complex, and that the mine/no-mine probabilities could be coded in a separate dimension - The pulse rate. In this paper, we describe these results in detail.

Duke Scholars

Author Stacy L. Tantum Electrical and Computer Engineering

Author Leslie M. Collins Electrical and Computer Engineering