Accession Number:

ADA091972

Title:

Addition of a 5/cm Spectral Resolution Band Model Option to LOWTRAN5.

Descriptive Note:

Final technical rept.,

Corporate Author:

AERODYNE RESEARCH INC BEDFORD MA CENTER FOR ELECTRO-OPTICAL SIGNATURE STUDIES

Report Date:

1980-10-01

Pagination or Media Count:

226.0

Abstract:

This report presents a modified version of the atmospheric transmission and radiation code LOWTRAN5 which includes 1 an increase in the spectral resolution from 20 to 5cm, 2 the addition of temperature dependent molecular absorption coefficients, and 3 the use of a multi-parameter, Doppler-Lorentz band model for calculation of molecular transmittance. A set of 5cm band model parameters have been developed using the molecular data in the Air Force Geophysics Lab HITRAN line compilation for the major atmospheric absorbers. The absorption coefficient, Sd, and line density, ld, band model parameters were determined at 5cm resolution from 400-10,000cm 1-25 micrometers and at 200, 225, 250, 275, and 300K. Examples of these parameters for H2O and the uniformly mixed gases are presented. In addition to the Sd and ld band model parameters, the need for and determination of the molecular continuum absorption due to the tails of lines originating outside a given spectral interval are presented. Comparisons of LOWTRAN5 transmittance and radiance calculations with the modified version, LOWTRAN5BMOD, are shown and discussed. Comparison of predictions using both versions of LOWTRAN5 with transmittance and radiance measurements are included. A detailed set of appendices are included which cover instructions for the required modifications to LOWTRAN5, implementation directions, program listings, and test cases. Author

Subject Categories:

  • Atmospheric Physics
  • Computer Programming and Software

Distribution Statement:

APPROVED FOR PUBLIC RELEASE