In recent years, the acoustic technology for landmine detection has demonstrated success in field testing. Acoustic-to-seismic responses of buried landmines are exploited for locating the targets. Field experiments have demonstrated that different burial conditions and different landmines show different linear frequency responses. Therefore, the landmine detection system uses broad-band excitations. Until now, the research work for acoustic landmine detection has primarily focused on demonstrating a high probability of detection and low false alarm rate through systematic field experiments, such as blind field tests, especially for anti-tank mines. However, the speed of detection has not yet been shown to meet operational requirements. In designing a moving platform, one must know how fast an acoustic detector can acquire high-quality data, and what factors limit increased moving speed. Based upon field test results, this paper investigates the relationship between the bandwidth of the pseudo-random excitation, frequency resolution of linear response measurements, speckle noise, and reliable moving speeds of acoustic/seismic sensors.
Recent success in using a laser Doppler vibrometer (LDV) based acoustic-to-seismic (A/S) landmine detection [Sabatier, J. M. and Xiang, N. IEEE Trans. Geoscience and Remote Sensing 39, 2001, pp.1146-1154.; Xiang, N. and Sabatier, J. M., J.Acoust. Soc. Am.113, 2003, pp. 1333-1341] and a ground penetrating synthetic aperture radar (GPSAR) [Bradley et al. Proc.SPIE, 4038, pp.1001-1007, 2000] suggested a novel configuration of fused sensors comprised of a LDV-based A/S detection sensor and a GPSAR. Extensive field experiments revealed that these two technologies can be considered 'orthogonal'. When used in concert, a fused configuration may significantly improve the probability of detection and reduce the false alarm rate. They function best against different types of landmines under different burial conditions because they exploit disparate phenomena to detect mines. In order to better understand the fused detection ability, a co-located field experiment has been conducted using both a LDV-based A/S sensor and a GPSAR. This paper will discuss the comparative experimental study using the recent co-located field scanning results.