Landmine Detection by Nuclear Quadrupole Resonance (NQR)

Abstract

Landmines continue to threaten U.S. and allied forces. Conventional mine detection sensors, such as ground penetrating radar (GPR), can give many false alarms due to natural and manmade objects in the ground having mine-like characteristics to these sensors. This can result in a slow advance rate as the forces must deal with these false alarms. Nuclear quadrupole resonance (NQR) technology is being developed by the U.S. Army for application to landmine detection as a confirmation sensor to verify the presence of landmines and eliminate false alarms from GPR. NQR technology has the capability to detect and discriminate explosives from other items in the environment and it can discriminate among the different types of explosives found in landmines.Recent field testing of an early prototype NQR landmine detection system developed by Quantum Magnetics, Inc. (QM) demonstrated high probability of detection and probability of false alarm rejection at scan times of about 20 seconds for TNT and a few seconds for RDX at 20°C. Current NQR research and development by the Army is focused on reducing the scan time for TNT.In 2004, the U.S. Army RDECOM CERDEC Night Vision and Electronic Sensors Directorate (NVESD) established a laboratory to investigate advanced NQR techniques for detection of landmines at Fort Belvoir, Virginia. The laboratory was established in collaboration with the U.S. Naval Research Laboratory (NRL), QM, King's College, London and the UK Defence Science and Technology Laboratory (Dstl). This paper reviews the basics of NQR technology, describes the capabilities of the laboratory at NVESD, and discusses the use of explosive simulants and proposed methods of reducing the scan time.

Performance Analysis of Techniques Used for Determining Land Mines

“…In recent studies, non-linear least-meanssquare detector and maximum likelihood detector that can also read the dependencies of the NQR frequencies to the temperature have been developed in order to increase the low signal to noise ratio. It is also possible to avoid from the disturbing effect of fertilizers with nitrogene content in the ground that can give rise to false alarms [44] [57].…”

“…In our study, NQR method is investigated for buried land mine detection and again the following variables are selected for performance criteria parameters for each work that is examined: soil type, material tested, test height, working rate and frequency, findings under these conditions [54] [55] [57]. Figure 6 gives the principle of the NQR method for mine detection.…”