Chapter 1 - The Detection Problem

• Published in: Aspects of Explosives Detection pp. 1 - 10
• Main Authors: Marshall, M., Oxley, J.C.
• Format: Book Chapter
• Language: English
• Published: Elsevier B.V 2009
• ISBN: 9780123745330; 9780444549365; 0444549366; 9780080923147; 0123745330; 0080923143
• DOI: 10.1016/B978-0-12-374533-0.00001-5

Prevention of explosions requires the detection of bombs, bomb makers, and bomb placers. State-sponsored actors and non-state-sponsored terrorists are the main threats on which explosives detection needs to focus. The geographical location such as an airport or a building, whether the threat is on (or in) people or objects, the target mobility, and whether the target is moveable or fixed are all factors that impose constraints on the detection techniques employed and influence the operational deployment of bomb detectors. In modern times, many techniques have been investigated for the detection of explosives and illicit chemicals. Imaging techniques such as radiography are quite good for recognizing bombs either visually or by computer-aided image recognition, but as they are not particularly sensitive, they detect suspect items of a certain minimum size. Detection of explosives is divided into bulk and trace technologies where the bulk detection looks for a mass with certain properties considered indicative of an explosive. In detecting the presence of an explosive compound at trace levels, the general approach is to look for a specific chemical from a library of target compounds rather than for a general property. To date, only two technologies have reached the original goal of certification, namely, X-ray computer tomography (CT) in 1996 and X-ray powder diffraction coherent Compton scattering in 2004.