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U.S. Department of Energy
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Monitoring atmospheric pollutants with a heterodyne radiometer transmitter-- receiver

Patent ·
OSTI ID:4367139
The presence of selected atmospheric pollutants including radioactive particles can be determined by transmitting an infrared laser beam of proper wavelength through the atmosphere, and detecting the reflections of the transmitted beam with a heterodyne radiometer transmitter-receiver using part of the laser beam as a local oscillator. The particular pollutant and its absortption line strength to be measured are selected by the laser beam wave length. When the round-trip path for the light is known or measured, concentration can be determined. Since pressure (altitude) will affect the shape of the molecular absorption line of a pollutant, tuning the laser through a range of frequencies, which includes a part of the absorption line of the pollutant of interest, yields pollutant altitude data from which the altitude and altitude profile is determined. (4 Claims, 5 Drawing Figures) (Official Gazette)
Research Organization:
Originating Research Org. not identified
NSA Number:
NSA-29-007845
Assignee:
to National Aeronautics and Space Administration
Patent Number(s):
US 3766380
OSTI ID:
4367139
Country of Publication:
United States
Language:
English