Remote Detection of Hazardous Liquids Concealed in Glass and Plastic Containers

Raman-based standoff detection systems have the potential to characterize materials through various transparent glass and plastic containers. This allows the analysis of the content without opening the container. In the Defense and Security arena, this implies to minimize exposure of operators to potentially harmful substances and helping to speed a screening process. The objective of this work is to study, in real field conditions, the remote detection of hazardous liquids concealed in commercial products bottles. A telescope assisted Raman system with a 488.0 nm excitation wavelength was used for noninvasive, nondestructive interrogation of the content of common liquid containers and determining if the liquid is the intended one or a concealed hazardous liquid. Commercial products such as: sodas, juices and liquors were mixed with hazardous liquids such as liquid explosives or chemical warfare agent simulants (CWAS) and characterized by remote Raman spectroscopy. Spectroscopic signatures of hazardous liquids were used to discriminate between consumer products liquids at 22 feet target-collector distance. The effect of the container type and color was also studied providing good understanding of the technique strengths and challenges. This technique has potential to be used as a detector for hazardous liquids at a check point or to inspect the contents of suspicious bottles remotely.