Infrared Continuum Absorption by Atmospheric Water Vapor in the 8-12- Micrometer Window

Abstract

We have carried out a detailed analysis of several long-path-length transmission measurements in the 8 to 12 micrometer atmospheric window in order to determine the extinction coefficient due to the water vapor continuum. Our results indicate that three modifications to the current LOWTRAN atmospheric transmission model are required. The first two corrections are an improved fit to the pure water vapor continuum absorption coefficient and the elimination of the atmospheric broadened continuum term. Finally, and most critically, a strong measured temperature dependence must be included in the water vapor continuum absorption coefficient. For path lengths ranging from 10 to 50 km, failure to incorporate these corrections can lead to errors in the computed transmission ranging from factors of 2 to more than 10,000.

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1976
Accession Number
ADA025377

Entities

People

  • John E. A. Selby
  • Lucien M. Biberman
  • Robert E. Roberts

Organizations

  • Institute for Defense Analyses

Tags

Communities of Interest

  • Advanced Electronics

DTIC Thesaurus Topics

  • Absorption
  • Absorption Coefficients
  • Carbon Dioxide Lasers
  • Coefficients
  • Databases
  • Frequency
  • Ground Level
  • Humidity
  • Inclusions
  • Infrared Equipment
  • Infrared Windows
  • Lasers
  • Light Sources
  • Measurement
  • Ultraviolet Equipment
  • Vapor Pressure
  • Water Vapor

Fields of Study

  • Physics

Readers

  • Spectroscopy.