Experimental Evaluation of a Concept for Standoff Detection of Explosives on Moving Targets

Abstract

Laser-based trace detection of explosives can be performed contact-free and very rapidly. These benefits make laser techniques highly desirable for security applications, e.g. at airports or public places. A number of different spectroscopic techniques covering wavelengths from the UV to the IR have been investigated for application in potential explosives detection systems. In many cases, these studies focus primarily on static scenarios where the target is at a fixed distance from the detection system. When transferring the spectroscopic system from the laboratory towards a real application, however, varying observation distances and angles must be considered, especially during security checks on moving targets, e.g. luggage, people. We will present a proposal for a UV Raman detection system designed to detect µg traces of explosives on a person's shoes. The spectroscopic system is combined with an optical tracking system that locates shoes and aligns the spectroscopic unit accordingly. Detection distance of the system is 1 m with a tolerance of about ±0.5 m to accommodate different target positions within the field of view. The system is developed at a laboratory scale and represents a first step towards a shoe scanner for the detection of explosives during security checks, e.g. at airports.