Algorithm for the calculation of absorption coefficient-pressure broadened molecular transitions /

This report describes an algorithm for the accelerated computation of the convolution of a Lorentz line shape (pressure broadened) with spectral line data. A computational savings of approximately 10 has been achieved over conventional methods. The Lorentz function has been decomposed into three functions, each of which is convolved independently at optional sampling intervals. Criteria for the determination of the sampling interval of the Lorentz function for a resultant error of 0.1 percent is described. The report contains a listing of the computer program based on the algorithm and sample results in the spectral region 3550 to 3650/cm due to water and carbon dioxide."Optical Physics Division Project 2310.""ADA047515 (from http://www.dtic.mil).""22 July 1976."Includes bibliographical references (pages 35-36).This report describes an algorithm for the accelerated computation of the convolution of a Lorentz line shape (pressure broadened) with spectral line data. A computational savings of approximately 10 has been achieved over conventional methods. The Lorentz function has been decomposed into three functions, each of which is convolved independently at optional sampling intervals. Criteria for the determination of the sampling interval of the Lorentz function for a resultant error of 0.1 percent is described. The report contains a listing of the computer program based on the algorithm and sample results in the spectral region 3550 to 3650/cm due to water and carbon dioxide.Mode of access: Internet

AFCRL atmospheric absorption line parameters compilation /

The report describes a compilation of the molecular spectroscopic parameters for a number of infrared-active molecules occurring naturally in the terrestrial atmsophere. The following molecules are included in this compilation: water vapor; carbon dioxide; ozone; nitrous oxide; carbon monoxide; methane; and oxygen. The spectral region covered extends from less than 1 micrometer to the far infrared, and data are presented on more than 100, 000 spectral lines. The parameters included in the compilation for each line are: frequency, intensity, half-width, energy of the lower state of the transition, vibrational and rotational identifications of the upper and lower energy states, an isotopic identification, and a molecular identification. A discussion is provided separately for each molecular species, indicating the sources and accuracy of the data and a general discussion of how the data were obtained."Optical Physics Laboratory Project 7670."AD0762904 (from http://www.dtic.mil)."26 January 1973."Includes bibliographical references (pages 63-67).The report describes a compilation of the molecular spectroscopic parameters for a number of infrared-active molecules occurring naturally in the terrestrial atmsophere. The following molecules are included in this compilation: water vapor; carbon dioxide; ozone; nitrous oxide; carbon monoxide; methane; and oxygen. The spectral region covered extends from less than 1 micrometer to the far infrared, and data are presented on more than 100, 000 spectral lines. The parameters included in the compilation for each line are: frequency, intensity, half-width, energy of the lower state of the transition, vibrational and rotational identifications of the upper and lower energy states, an isotopic identification, and a molecular identification. A discussion is provided separately for each molecular species, indicating the sources and accuracy of the data and a general discussion of how the data were obtained.Mode of access: Internet

Comparison of 8 to 12 micrometer and 3 to 5 micrometer CVF transmissometer data with LOWTRAN calculations /

This report contains a description and analysis of a series of atmospheric transmittance measurements taken at the Targeting Systems Characterization Facility, Wright-Patterson Air Force Base, Ohio with a circular variable filter (CVF) transmissometer. The data cover the spectral regions from 8- to 12-micron and from 3- to 5-micron for both 8-km and 2.25-km atmospheric paths. The instrumentation is described and comparisons of the data with calculations using the atmospheric transmittance and background radiance code, LOWTRAN 6, are presented. Keywords include: Atmospheric transmittance; Atmospheric optics; Infrared; Attenuation; Absorption; and Aerosols.Optical Physics Division Project 7670, 2004."26 June 1984."Distributed to depository libraries in microfiche.Cover title.Includes bibliographical references (page 63).Scientific Interim.This report contains a description and analysis of a series of atmospheric transmittance measurements taken at the Targeting Systems Characterization Facility, Wright-Patterson Air Force Base, Ohio with a circular variable filter (CVF) transmissometer. The data cover the spectral regions from 8- to 12-micron and from 3- to 5-micron for both 8-km and 2.25-km atmospheric paths. The instrumentation is described and comparisons of the data with calculations using the atmospheric transmittance and background radiance code, LOWTRAN 6, are presented. Keywords include: Atmospheric transmittance; Atmospheric optics; Infrared; Attenuation; Absorption; and Aerosols.Mode of access: Internet