21 August 2001 Concealed weapons detection system using uncooled pulsed imaging arrays of millimeter-wave bolometers
Author Affiliations +
We describe a system for detection of concealed weapons based on imaging the millimeter-wave reflectance contrast between the weapon and the human body. An architecture based upon pulsed illumination and gated integration has a large advantage in sensitivity over chopped CW illumination and synchronous detection. A simple sensitivity estimate based on an assumed range of 8 m, a 30 Hz frame rate, a primary collection area of 30 cm diameter, and an overall optical efficiency of 50 percent, yields a noise-equivalent reflectance difference of 0.66 percent in a single frame. The uncooled niobium micro bolometers provide a measured noise-equivalent power of 100 pW/Hz1/2 and a time constant of 175 ns, well matched to the source pulse width and the system sensitivity requirements. Optical coupling is provided by resonant slot-ring antennas, distributed in a focal plane array covering a single 75 mm diameter wafer. The optical and electrical systems used for coupling signals into and out of the focal plane array are also described.
© (2001) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Erich N. Grossman, Erich N. Grossman, Shalva Nolen, Shalva Nolen, Nicholas G. Paulter, Nicholas G. Paulter, Carl D. Reintsema, Carl D. Reintsema, } "Concealed weapons detection system using uncooled pulsed imaging arrays of millimeter-wave bolometers", Proc. SPIE 4373, Passive Millimeter-Wave Imaging Technology V, (21 August 2001); doi: 10.1117/12.438138; https://doi.org/10.1117/12.438138

Back to Top