Application of Millimeter-Wave Radiometry for Remote Chemical Detection

• Published in: IEEE transactions on microwave theory and techniques Vol. 56; no. 3; pp. 700 - 709
• Main Authors: Gopalsami, N., Bakhtiari, S., Elmer II, T.W., Raptis, A.C.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.03.2008; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: AIR; Applied sciences; CALIBRATION; Chemical detection; Chemicals; Circuit properties; DETECTION; Electric, optical and optoelectronic circuits; Electronics; Exact sciences and technology; Feasibility; Fuel processing industries; Gas industry; GASES; Microwave circuits, microwave integrated circuits, microwave transmission lines, submillimeter wave circuits; Microwaves; Millimeter wave measurements; millimeter waves; NEVADA TEST SITE; NITRIC OXIDE; NUCLEAR FUEL CYCLE AND FUEL MATERIALS; NUCLEAR FUELS; On-line systems; PLUMES; PROCESSING; Prototypes; RADIANT HEAT TRANSFER; radiometer; RADIOMETERS; Radiometry; remote sensing; Solids; Spectra; Spectral lines; TARGETS; Testing; Ground based measurement; Microwave; Wave detection; On-line systems; Calibration; Passive system; millimeter waves; Baseline; Switching; Field experiment; Remote sensing; Millimetric wave; Low pressure; Radiometry; Feasibility; Radiative transfer; Chemical detection; Non contact measurement; Radiometer
• ISSN: 0018-9480; 1557-9670
• DOI: 10.1109/TMTT.2008.916985

Passive millimeter-wave systems have been used in the past to remotely map solid targets and to measure low-pressure spectral lines of stratospheric and interstellar gases; however, its application to pressure-broadened spectral line detection of industrial emissions is new. We developed a radiative transfer model to determine feasibility and system requirements for passive millimeter-wave spectral detection of terrestrial gases. We designed and built a Dicke-switched multispectral radiometer in the 146-154-GHz band to detect nitric oxide (NO), a prototypical gas of nuclear fuel processing operations. We first tested the spectral detection capability of the radiometer in the laboratory using a gas cell and then field tested it at the Nevada test site at a distance of 600 m from a stack that released hot plumes of NO and air. With features such as Dicke-switched integration, frequent online calibration, and spectral baseline subtraction, we demonstrated the feasibility of remote detection of terrestrial gases by a ground-based radiometer.