Further Measurements of the Submillimeter Background at Balloon Altitude

Measurements of the far-infrared background radiation were made with a balloon-borne radiometer at an altitude of 44 km. Equivalent blackbody temperatures of ${2.55}_{-0.45\mathrm{}}^{+0.25\mathrm{}}$, ${2.45}_{-1.05\mathrm{}}^{+0.45\mathrm{}}$, and ${2.75}_{-2.75\mathrm{}}^{+0.8\mathrm{}}$ °K were obtained for the background radiation in bandwidths extending from 1 to 11.5, 13.5, and 18.5 ${\mathrm{cm}}^{-1\mathrm{}}$. The total measured flux in the largest bandwidth is dominated by the atmospheric emission by ozone and water. The radiation of these atmospheric components was determined independently in a separate pair of radiometer spectral responses.