Vyacheslav Aranchuk - aranchuk@olemiss.edu
University of Mississippi
1 Coliseum Drive
University, MS 38677
James M. Sabatier - sabatier@olemiss.edu
University of Mississippi
1 Coliseum Drive
University, MS 38677
Richard Burgett - rburgett@olemiss.edu
University of Mississippi
1 Coliseum Drive
University, MS 38677
Popular version of paper 3aEAa1
Presented Wednesday morning, May 25, 2011
161st Meeting of the Acoustical Society of America, Seattle, WA, USA
The detection and neutralization of landmines is an important task because of military, humanitarian, and environmental impacts.B More than 100 million mines have been laid in the world, killing and injuring thousands of innocent people and preventing economical use of land.B
The most commonly used devices for landmine detection are metal detectors. They work by measuring the disturbance of an emitted electromagnetic field caused by the presence of a metallic object in the ground.B These detectors cannot differentiate a real mine from metallic debris, such as metal scraps, shrapnel, etc. This results in the high false alarm rate: 100-1000 false alarms for each real mine. Each false alarm means a waste of time and causes a loss of concentration. Moreover, most of the modern mines are made of plastic and have low metal content, which poses severe difficulties for metal detectors.
One of the new most-successful landmine detection methods uses low frequency acoustic waves in the ground. The concept of the method is shown in Figure 1.
Figure 1. Concept of acoustic detection of buried landmines
The method is based on excitation of mechanical vibration of the ground using sound waves, for example created by a loudspeaker, and sensing vibration of the ground surface in many points remotely with a laser vibration sensorba laser vibrometer. A mine is a more compliant object than soil and natural objects like rocks and roots, because it is a complex mechanical structure. Mines also exhibit a resonance while natural clutter objects donbt. As a result, the vibration amplitude of the ground surface above a mine is higher than the vibration amplitude of the surrounding area. A laser vibrometer measures the vibration in many points of the ground surface, to create a vibrational map of the interrogated area. A buried landmine can be detected by higher vibration amplitude of the surface area.
A multiple beam laser vibrometer, which can sense vibration of the ground in many points simultaneously, has been developed by MetroLaser, Inc. and the University of Mississippi. A laser acoustic sensor based on the multiple beam laser vibrometer can scan one square meter of the ground surface in less than twenty seconds.B The current research is focused on increasing the speed of detection.