Share Email Print

Proceedings Paper

FTIR Measurements Of Minor Atmospheric Constituents
Author(s): F. J. Murcray; D. G. Murcray; F. H. Murcray; A. Goldman; R. D. Blatherwick
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

The major components of the Earth's atmosphere, nitrogen, oxygen and argon, are essentially transparent to infrared radiation. Most of the minor and trace gases in the atmosphere have significant infrared absorptions, which provide a means of measuring their abundance. For many years, we have been using the infrared as a remote sensing tool. As Fourier Transform systems (FTS) have developed, they have been increasingly used in our work. We primarily use two techniques for atmospheric measurements: solar absorption spectra and atmospheric emission spectra. In the solar absorption case, the sun is used as an intense source, and the measurement is similar (in principle) to that carried out routinely in the laboratory. Unfortunately, no reference (vacuum) path is readily available, the sample (atmosphere) is not under uniform temperature or pressure conditions and the composition is not uniform. Despite the complications, accurate determinations of gas amounts can be made in many cases, and path lengths unattainable in the laboratory can yield significant information about the molecular spectroscopy of some compounds. Interferometer systems have advantages for recording solar spectra in the infrared: relatively small size for comparable resolution and a highly accurate frequency scale. In most cases there is no multiplex advantage, but the throughput may be higher. FTS can also cover broad spectral intervals, which allows quantification of several gases simultaneously. The atmosphere is a very weak infrared source, and instrument sensitivity is of primary importance. FTS may or may not have a multiplex advantage, but it still provides an accurate frequency scale and substantial throughput.

Paper Details

Date Published: 1 December 1989
PDF: 6 pages
Proc. SPIE 1145, 7th Intl Conf on Fourier Transform Spectroscopy, (1 December 1989); doi: 10.1117/12.969378
Show Author Affiliations
F. J. Murcray, University of Denver (United States)
D. G. Murcray, University of Denver (United States)
F. H. Murcray, University of Denver (United States)
A. Goldman, University of Denver (United States)
R. D. Blatherwick, University of Denver (United States)

Published in SPIE Proceedings Vol. 1145:
7th Intl Conf on Fourier Transform Spectroscopy
David G. Cameron, Editor(s)

© SPIE. Terms of Use
Back to Top