Laser-based standoff detection of explosives: a critical review

Abstract

A review of standoff detection technologies for explosives has been made. The review is focused on trace detection methods (methods aiming to detect traces from handling explosives or the vapours surrounding an explosive charge due to the vapour pressure of the explosive) rather than bulk detection methods (methods aiming to detect the bulk explosive charge). The requirements for standoff detection technologies are discussed. The technologies discussed are mostly laser-based trace detection technologies, such as laser-induced-breakdown spectroscopy, Raman spectroscopy, laser-induced-fluorescence spectroscopy and IR spectroscopy but the bulk detection technologies millimetre wave imaging and terahertz spectroscopy are also discussed as a complement to the laser-based methods. The review includes novel techniques, not yet tested in realistic environments, more mature technologies which have been tested outdoors in realistic environments as well as the most mature millimetre wave imaging technique.

Towards optoelectronic detection of explosives

“…The interaction yields an optical response, which is collected by an optical receiver. As were described in li− teratures the standoff optical methods deliver the sensi− tivities reaching even the ppb level [56][57][58].…”

Standoff Detection of Explosives at 1 m using Laser Induced Breakdown Spectroscopy

“…LIBS can be a potential solution for application where the closer proximity of the operator to the sample is inaccessible/threatening or harsh environments. Standoff capability of LIBS offers a suitable choice for identification of hazardous materials including explosives in such situations, which otherwise is not possible by other conventional vapour based techniques like gas chromatography 12 and ion-mobility spectrometry (IMS) [13][14][15] . The standoff detection of explosives is a multifold challenging task where the signal strength decreases inversely with distance, inevitable losses in intensity arise due to atmospheric absorption/scattering of light and the possibility of the sample being present on varied types of materials.…”

A Data Acquisition and Detection Algorithm for Signal Analysis in Material Detection

“…In order to advance the detection procedure, standoff technique is to be used. It is known that best possible outcomes for standoff detection are achieved through optical laser techniques [8]. In this paper, we discuss about spectrometry technique in detail.…”