The spectral absorption file (usually named with a .abs or .gas file
extension) is used by the Classic Absorption model, which is commonly
used with the Gas radiometry solver.
This file is used to describe the absorption of volume as a function of wavelength. Since this data is commonly used with gases or plumes (which can vary in concentration), the units of the absorption coefficients are for a given concentration and over a given optical path length.
Format Details
The file contains the spectral absorption as a function of frequency (in wavenumbers) in a simple, two column text file. The columns can be separated by any whitespace (spaces, tabs, etc.). The spectral samples must be ordered in decreasing order. The units of the absorption coefficients are inverse ppm meters or 1/ppm-m.
Example File
3700.000000 4.019800e-02 3699.500000 1.237900e-02 3699.000000 5.621300e-03 3698.500000 3.779900e-03 3698.000000 2.733500e-03 3697.500000 2.178500e-03 [lines deleted for documentation purposes] 502.120000 2.651600e-03 501.640000 3.204400e-03 501.160000 4.839500e-03 500.670000 8.929400e-03 500.190000 3.098300e-02
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The spectral samples do not need to be on regular intervals. |