Terahertz standoff identification under real world conditions

Many chemicals, including hazardous substances, can be distinguished based on their spectral fingerprints in the terahertz range under laboratory conditions. In a real-world standoff environment, additional factors such as water vapor absorption in humid air, clothes and packaging materials, and the surface properties of the particular sample make this task more difficult. We have performed measurements and simulations in order to quantify these influences and improve on the limits of detection.