NIST researchers demonstrate 120-element focal-plane array for concealed weapons detection.Millimeter wavelength imaging is a natural approach for concealed weapons (Law) dangerous weapons so carried on the person as to be knowingly or willfully concealed from sight, - a practice forbidden by statute.<- in some states! -> See under Concealed. See also: Concealed Weapon detection (CWD CWD chronic wasting disease. ) because of the transparency of clothing and the spatial resolution (Data West Research Agency definition: see GIS glossary.) A measure of the accuracy or detail of a graphic display, expressed as dots per inch, pixels per line, lines per millimeter, etc. It is a measure of how fine an image is, usually expressed in dots per inch (dpi). achievable in this spectral region. However, large-format arrays of mm-wave detectors, analogous to CCDs in the visible region, do not yet exist. Recently, NIST (National Institute of Standards & Technology, Washington, DC, www.nist.gov) The standards-defining agency of the U.S. government, formerly the National Bureau of Standards. It is one of three agencies that fall under the Technology Administration (www.technology. researchers, working under the auspices of an Office of Law Enforcement Standards program, have demonstrated a 120-element focal-plane array of antenna-coupled microbolometers optimized for wave-lengths near 3 mm (100 GHz frequency). The microbolometers are 1.6 [micro]m x 10 [micro]m strips of thin-film Nb, and are coupled to free space through Au slot-ring antennas that are 850 [micro]m in diameter, while the overall array is 75 mm in diameter. A fast, low-noise readout (1) A small display device that typically shows only a few digits or a couple of lines of data. (2) Any display screen or panel. for the array has been built, which allows the sensitivity of the array to be limited by the fundamental Johnson noise of the microbolometers. Electrical noise-equivalent power for each pixel is approximately 100 pW/H[z.sup.1/2], with a response time of 400 ns. The focal-plane array enables development of several types of systems envisaged for CWD applications, including portals for airport passenger screening and police cruiser-mounted standoff systems. CONTACT: Erich Grossman, (303) 497-5102: grossman@boulder.nist.gov. |
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