A study of moderate resolution (1 cm−1) atmospheric transmission measurements made over a 5.7-km path and under a wide range of temperatures and humidities is presented. A description of the Fourier interferometric transmissometer (FIT) used for this study and a detailed analysis of the experimental protocol developed for that type of instrument are given. Results for the 2.8–5.5-μm spectral window are compared to calculations using the lowtran6 and fascod2 transmission codes. We examine the accuracy with which these codes predict transmittance in spectral domains (1800–2000 and 3200–3500 cm−1) strongly affected by water vapor concentration. Preliminary analysis, indicates that although lowtran6 predicts well the summer transmittance (+30.3° C) there are significant divergences for the winter case (−21.4° C). The comparison of fascod2 with experimental results shows much closer agreement than lowtran6 for both summer and winter cases.
© 1990 Optical Society of America
Original Manuscript: October 12, 1989
Published: September 1, 1990
Jean-Marc Theriault, Pierre L. Roney, and Francoise Reid, "Atmospheric transmission in the 2.8–5.5-μm region: description of the Fourier interferometric transmissometer and typical result at low temperatures," Appl. Opt. 29, 3654-3666 (1990)