Stand-off Detection of Trace Explosives by Photo-Induced Acoustic Signature Analysis

Technology

This invention detects the presence of an explosive by using a pulsed focused energy source located at a target distance away from a substrate. The pulsed focused energy source can be a pulsed laser, microwave energy, or a sonic energy source. If there is an explosive on the substrate, the pulsed energy source releases the explosive’s internal energy which generates an acoustic wave. The invention also includes a detector adapted to detect the acoustic wave at a distance away from the substrate. The detector can be a microphone or a laser vibrometer and the target distance can be in a range of between about 1 meter and about 1,000 meters.

It should be noted that there are no currently fielded standoff detection techniques for trace. There are trace detection systems; however, they are not standoff, but rather rely on ingestion of material and are thus slow and inefficient.

Problem Addressed

Current ways of detecting explosives from a distance include detecting the weak acoustic signal caused by laser-induced sample heating or detecting auxiliary properties (chemical or optical) of the explosives. The methods either have distance limitations or often generate false positives. There is a need for a method of detecting explosives at a distance that is highly accurate.

Advantages

• Higher accuracy than other conventional methods for detecting explosives at a distance.
• Fast, stand-off, and specific detection of trace amounts of explosive materials with a single-wavelength focused energy source.