Abstract

For several years we have been making measurements of atmospheric transmittance in the wavelength region 2.8 to 15 μm under various meteorological conditions. The aim of this work was to compare experimental measurements of the transmittance with the predictions of the LOWTRAN computer codes. In this paper we present measurements of the contribution to the total atmospheric absorption made by the water-vapour continuum in the regions 4.3-5.5 μm and 8-12 μm. These contributions are included incorrectly in LOWTRAN 4 (and also in LOWTRAN 5) (1,2) and make a significant difference to the atmospheric transmittance under humid conditions or along long gorizontal paths.

© 1985 Optical Society of America