Concealed Weapons Detection System Using Uncooled, Pulsed, Imaging Arrays of Millimeter-Wave Bolometers

Published

August 1, 2001

Author(s)

Erich N. Grossman, Shalva Nolen, Nicholas Paulter, Carl D. Reintsema

Abstract

We describe a system for detection of concealed weapons based upon imaging the millimeter-wave reflectance contrast between the weapon and the human body. An architecture based upon pulsed illumination and gated detection has a large advantage in sensitivity over chopped CW illumination and synchronous detection. A simple sensitivity estimate based on an assumed range at 8 m, a 30Hz frame rate, a primary collection area of 30 cm diameter, and an overall optical efficiency of 50 %, yields a noise-equivalent reflectance difference of 0.67% in a single frame. The uncooled niobium microbolometers provide a (measured) noise equivalent power of 100 pW/Hz^1/2 and a time constant of 200 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 mm diameter wafer. The optical and electrical systems used for coupling signals into and out of the focal array are also describe.

Proceedings Title

Proc. SPIE Conf. on Passive Millimeter-Wave Imaging Technology V

Volume

4373

Conference Dates

April 16-20, 2001

Conference Location

Orlando, FL, USA

Pub Type

Conferences

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Keywords

array, bolometer, concealed weapons, imaging, millimeter-wave

Citation

Grossman, E. , Nolen, S. , Paulter, N. and Reintsema, C. (2001), Concealed Weapons Detection System Using Uncooled, Pulsed, Imaging Arrays of Millimeter-Wave Bolometers, Proc. SPIE Conf. on Passive Millimeter-Wave Imaging Technology V, Orlando, FL, USA, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=13483 (Accessed December 12, 2024)