INFRARED RADIATION FROM THE $SKY^{*}$

$^{*}$This work was done under contract between Wright Air Development Center and The Ohio State University Research Foundation. $^{1}$Butler, NRL Report 3981, June, 1952. $^{2}$Oetjen, Bell, Young, Metter, J. Opt. Soc. Am. 45, 403 (1955). $^{3}$Sloan, Shaw, and Williams, J. Opt. Soc. Am. 45, 445 (1955). $^{4}$Burch and Shaw. J. Opt. Soc. Am. 47, 227 (1957).Author Institution: The Ohio State University“Data will be presented to show the measured spectral radiance of the sky (0$^\circ K$ reference temperature) in the one to twenty microns wavelength region. The relative importance of atmospheric $emission^{1,2,3,4}$ and scattered sunlight will be shown. The importance of the temperature, water vapor content, altitude, sun angle, elevation, and azimuth will be illustrated with typical spectra. A semi-quantitative explanation of the effects of these variables will be given on the basis of a simple model of the atmosphere.