Abstract

A number of equations are derived for the absorptance along a slant path. The absorptances of slant and homogeneous paths are compared. Various combinations of assumptions are made in the derivation of these equations as to the variation of the temperature and absorber concentration along the path, the extent and nature of the overlapping of the spectral lines, the variation of the intensity and half-width from line to line, the shape of the spectral lines, and the extent of the frequency interval considered. The particular assumptions applicable to each result are clearly stated. A general method is developed for obtaining slant path absorptances from homogeneous path data when either the weak or strong line approximation is valid. A combination of the weak and strong line results gives new general expressions for the relationship of slant and homogeneous path absorptance. These results are correct in both of the weak and strong line limits and in addition provide a good approximation for all values of the parameters.

© 1963 Optical Society of America

The Absorption of Laser Radiation Along Atmospheric Slant Paths

Gilbert N. Plass
Appl. Opt. 5(1) 149-154 (1966)

Spectral Band Absorptance of Radiation Traversing Two or More Cells in Series

Gilbert N. Plass
Appl. Opt. 4(1) 69-78 (1965)

Calculated Slant-Path Absorption and Distribution of Atmospheric Water Vapor

Robert F. Calfee and David M. Gates
Appl. Opt. 5(2) 287-292 (1966)

Models for Spectral Band Absorption*

Gilbert N. Plass
J. Opt. Soc. Am. 48(10) 690-703 (1958)

Transmittance of Carbon Dioxide and Water Vapor Over Stratospheric Slant Paths

Gilbert N. Plass
Appl. Opt. 3(4) 479-482 (1964)