ANALYSIS OF LONG-PATH, LASER-CALIBRATED ATMOSPHERIC TRANSMISSION SPECTRA FROM $3\;\mu m$ TO $5\;\mu$m

Abstract

During the past two years the Infrared Mobile Optical Radiation Laboratory (IMORL) facility of the Naval Research Laboratory has assembled an extensile data base of high-resolution $(0.08\;cm^{-1})$, laser-calibrated, atmospheric transmission spectra covering a wide range of meteorological conditions. By numerically degrading the spectral resolution of the long-path, absolute transmission spectra from the NRL-IMORL data base, these measurements have been compared with the predictions of the LOWTRAN atmospheric propagation model. Results of comparisons made in the $1800\;cm^{-1}$ to $3200\;cm^{-1}$ atmospheric window indicate reasonably good agreement, particularly for high-visibility conditions. Based on this analysis, an improved algorithm has been derived for the LOWTRAN water-vapor-continuum estimates.