Acoustic-to-seismic transfer function attribute for discrimination of false alarms and landmine detection

Abstract

Acoustic detection of landmines based on the analysis of both spatial and frequency dependencies of the acoustic-to-seismic transfer function (A/S TF) utilizes the difference between mine impedance and the impedance of the surrounding ground. However, some deeply buried mines and some types of mines are hard to detect due to the natural variability of the ground. This work addresses the problem of false alarms and clutter (high values of the A/S TF in some frequency bands) that mimic the physics of a buried landmine. A time-scale, linear method (wavelet analysis) was used for improving the probability of landmines detection. Wavelet analysis of the calculated and measured signals permit one to find stable characteristics typical of the undisturbed ground, the disturbed ground, and the ground with a mine. The wavelet analysis showed that these characteristics may be used for the discrimination of landmines from false alarms. These characteristics also may be used as the additional criterion to find mines which are hard to locate by traditional methods. The advantages of the suggested technique are illustrated using the experimental data. Possibilities for buried landmine classification are discussed. [Work supported by ONR Grant N00014-02-1-0878.]