Atmospheric Absorption in Microwave Solar Observation and Solar Flux Measurement at 17 Gc/s

A 17 Gc/s radio polarimeter was constructed at the Tokyo Astronomical Observatory, and the routine solar observation has been made since May 1964. The solar flux is measured by a comparison of the sky and the ambient temperatures. It is shown theoretically and observationally that the absorption of the terrestrial atmosphere does not affect the flux measurement. A procedure to correct the atmospheric absorption at higher frequencies is also shown. By six month observations, the apparent disk temperature of the sun at 17 Ge/s is in the present quiet period.