Measurement of the complete far-field pattern of large antennas by radio-star sources

A correlation technique for measuring the complete far-field patterns of large-aperture antennas is described and evaluated analytically. The technique uses radio-star sources and employs an auxiliary antenna for providing a reference signal for crosscorrelation with the test-antenna signal. The major advantages provided by the correlation method, relative to single-antenna radiometric systems, are improved sensitivity, greater interference rejection, and the capability for measuring polarization and phase responses of test antennas, in addition to their gain pattern. Full realization of the ultimate capabilities of the technique requires the performance of crosscorrelation for high ratios of pre-detection to post-detection bandwidths.