Determination of KU-band earth station antenna G/T using the moon as RF source

The Moon has been successfully used as a calibrated source of RF emissions in determining the gain-to-noise-temperature ratios (G/Ts) of medium size C-band antennas. This method to determining G/T has recently been applied to K_u-band antennas as well, and the results have agreed well with independent measurements of gain and temperature. However, because of the fact at the Moon´s angular diameter may extend beyond the main lobe of lobe antenna, a gain correction factor has to be applied. This factor requires accurate knowledge of the gain pattern for its determination, but once such knowledge has been obtained by pattern measurement, the G/T can be calculated with reasonable accuracy.