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Temperature dependence of Lorentz air-broadening and pressure-shift coefficients of (12)CH4 lines in the 2.3-micron spectral regionHigh-resolution (0.01/cm) absorption spectra of lean mixtures of CH4 in dry air were recorded with the McMath-Pierce Fourier transform spectrometer (FTS) of the National Solar Observatory on Kitt Peak at various temperatures between 24 and -61 C. The spectra have been analyzed to determine the values at room temperature of pressure-broadened widths and pressure-induced shifts of more than 740 transitions. The temperature dependence of air-broadened widths and pressure-induced shifts was deduced for approx. 370 transitions in the nu(sub 1) + nu(sub 4), nu(sub 3) + nu(sub 4), and nu(sub 2) + nu(sub 3) bands of (12)CH4 located between 4118 and 4615/cm. These results were obtained by analyzing a total of 29 spectra simultaneously using a multi-spectral non-linear least-squares fitting technique. This new technique allowed the determination of correlated spectral line parameters (e.g. intensity and broadening coefficient) better than the procedure of averaging values obtained by fitting the spectra individually. This method also provided a direct determination of the uncertainties in the retrieved parameters due to random errors. For each band analysed in this study the dependence of the various spectral line parameters upon the tetrahedral symmetry species and the rotational quantum numbers of the transitions is also presented.
Document ID
19950053399
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Devi, V. Malathy
(The College of William and Mary, Williamsburg, VA United States)
Benner, D. Chris
(The College of William and Mary, Williamsburg, VA United States)
Smith, M. A. H.
(NASA Langley Research Center Hampton, VA, United States)
Rinsland, C. P.
(NASA Langley Research Center Hampton, VA, United States)
Date Acquired
August 16, 2013
Publication Date
March 1, 1994
Publication Information
Publication: Journal of Quantitative Spectroscopy & Radiative Transfer
Volume: 51
Issue: 3
ISSN: 0022-4073
Subject Category
Instrumentation And Photography
Accession Number
95A84998
Distribution Limits
Public
Copyright
Other

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