Atmospheric attenuation of microwave radiation

A specially constructed combined radio telescope-radio sextant has provided continuous measurement of the power from the sun. The change in received power with zenith angle has been used to estimate the attenuation due to the atmosphere at the wavelength of 8.7 mm. Values ranging from 0.031 to 0.067 db per km at sea level were observed for days with a wide variety of weather conditions. Qualitative statements concerning attenuation under conditions of unusually heavy rainfall are made.