Atmospheric monitoring using infrared heterodyne radiometry
Abstract
The potential of infrared heterodyne radiometers (IHR's) for remote passive monitoring of such atmospheric constituents as SO2, O3, C2H4, and NH3 is discussed. It is shown that the infrared heterodyne receiver provides excellent sensitivity and specificity as compared to conventional infrared detectors, and that it can be tuned to discrete portions of the infrared spectrum by proper selection of the laser local oscillator. For atmospheric monitoring applications, the IHR telescope collects the thermal energy radiating from the earth at a clear spectral window, or a spectral region where the signature lines of the constituent gases at various layers of the atmosphere will be energized by the upwelling thermal radiation. When the vertical temperature distribution of the atmosphere is known, the concentration of the constituent gas can be determined as a function of altitude from the radiance data collected at the IHR, using an iterative technique.
- Publication:
-
International Instrumentation-Automation Conference
- Pub Date:
- 1974
- Bibcode:
- 1974isa..conf..403P
- Keywords:
-
- Air Pollution;
- Atmospheric Composition;
- Infrared Radiometers;
- Pollution Monitoring;
- Spectral Signatures;
- Combustion Products;
- Exhaust Gases;
- Lasers;
- Optical Heterodyning;
- Remote Sensors;
- Instrumentation and Photography