Comparison of the EMI Long Sea Path Transmittance Measurements With LOWTRAN 5 Calculations

Abstract

A series of broadband visible and infrared transmittance measurements made by EMI Ltd. over a 20 km sea path are compared to transmittances calculated by LOWTRAN 5. The purpose of the comparison is primarily to test the validity of the Maritime aerosol model in LOWTRAN under realistic conditions, and incidentally to test the molecular extinction in several window regions. The results of this comparison are the following: (a) the Maritime aerosol model provides a good description of aerosol extinction for conditions of a moderate wind blowing over the open ocean; (b) the calculated molecular extinction in the 8 to 12 micron region is accurate to within 7 percent in the log of the transmittance, although there is an indication the water vapor continuum absorption coefficient may be slightly too large; (c) the calculated molecular extinction in the 4.5 to 5.0 micron region is seriously underpredicted due to the lack of a water vapor continuum in this region.

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Document Details

Document Type
Technical Report
Publication Date
May 28, 1980
Accession Number
ADA092593

Entities

People

  • William O. Gallery

Organizations

  • Air Force Research Laboratory

Tags

Communities of Interest

  • Advanced Electronics

DTIC Thesaurus Topics

  • Absorption Coefficients
  • Air Force
  • Air Pressure
  • Calibration
  • Coefficients
  • Data Sets
  • Detectors
  • Frequency
  • Geography
  • Humidity
  • Lasers
  • Light Sources
  • Measurement
  • Particle Size
  • Particles
  • Water Vapor
  • Wind Direction

Fields of Study

  • Physics

Readers

  • Atmospheric Remote Sensing.