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).