Background Variations in Millimeter Wave Telescopes Due to the Radome Structure

摘要

The difference between measured and theoretical standard deviations of atmospheric fluctuations in radome covered telescopes used in dual beam radio source flux measurements is discussed. The main reason for this increased deviation is shown to be background noise from the telescope surroundings, which is reflected from the radome frame. A so-called synchronous tracking method is introduced for eliminating the effect of the background. A higher tapering of the feed horn is possible, but lowers the total efficiency of the telescope.