Paper
16 October 2007 A new model for calculating infrared background radiance at all altitudes including atmospheric clutter and clouds
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Abstract
A new correlated-k algorithm has recently been incorporated into SAMM-2, the Air Force Research Laboratory background radiance and transmission code. SAMM-2 incorporates all of the major components necessary for background scene generation at all altitudes: atmospheric characterization, solar irradiance, molecular chemical kinetics and molecular spectroscopic data. The underlying physical models are applicable for both low-altitude local thermodynamic equilibrium (LTE) conditions as well as high-altitude non-LTE (NLTE) conditions. Comprehensive coverage in the .4 to 40 micron (250 to 25,000 wavenumber) wavelength region for arbitrary lines-of-sight (LOS) in the 0 to 300 kilometer altitude regime is provided. A novel 1 cm-1 resolution correlated-k algorithm has been developed in order to provide the orders-of-magnitude increase in computational efficiency when compared to the existing SAMM-2 line-by-line (LBL) algorithm and applicable to both LTE and NLTE atmospheric conditions. The SAMM-2 correlated-k algorithm processes molecular lines at runtime by reading line center information from the HITRAN 2000 database and computing statistical cumulative probability distributions within a spectral interval under the presumption of a Voigt line shape profile. This algorithm is useful for treating atmospheric phenomena at all altitudes requiring a spectrally monochromatic treatment of the atmospheric transmission and/or radiance, including multiple scattering or atmospheric structure.
© (2007) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
R. Panfili, H. Dothe, J. W. Duff, J. Gruninger, and J. H. Brown "A new model for calculating infrared background radiance at all altitudes including atmospheric clutter and clouds", Proc. SPIE 6745, Remote Sensing of Clouds and the Atmosphere XII, 67451M (16 October 2007); https://doi.org/10.1117/12.738140
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KEYWORDS
Absorption

Databases

Atmospheric modeling

Doppler effect

Analytical research

Molecular spectroscopy

Algorithm development

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