Impact of atmospheric layering on lowtran 6 radiance calculations

Abstract

Measurements of 8-12-microm near-horizon sky radiances and meteorological parameters over the ocean near San Diego, CA, were used to evaluate the sky radiance algorithm of LOWTRAN 6. Discrepancies in measured and calculated sky radiances previously attributed to the neglect of multiple scattering effects of aerosols can be overcome by introducing additional low level layers in the calculations of LOWTRAN 6. A comparison between radiance calculations using the single scattering, additive layer approach and those using a multiple scattering version of LOWTRAN raises questions about the applicability of the multiple scattering approach in the far infrared region.

<title>Impact of atmospheric layering on LOWTRAN radiance calculations</title>

“…In earlier work, Ben Shalom et al (1983) , Hughes (1987) and Wollenweber (1990) presented results which proved the dependence of LOWTRAN radiances on layer thickness of the atmospheric model used. Especially for optical paths close to the horizon LOWTRAN 6 calculated radiances showed a strange behaviour with zenith angle (Wollenweber, 1990), that could be fixed by subdividing the atmospheric layers.…”