Observations of Solar and Lunar Radiation at 15 Millimeters

Observations of the radiation from the sun and the moon in a wide wavelength band centered approximately at 1.5 mm are reported. These waves were detected with a Golay detector using a searchlight mirror for a telescope. Measurements of atmospheric extinction are reported and compared with calculations of water vapor absorption which have been made by J. H. Van Vleck. It is found that the measured extinction is greater than the calculated.Observations of the radiation emitted by the moon at different phases are reported.The transmittances of some materials to the 1.5-mm waves from the sun are included.