Digital spacecraft antenna tracking system

A processor (30) of a digital tracking control receiver (24) compares each tracking antenna output received through a multiplexer (20), with a set of predetermined reference response vectors stored in memory (32), to determine direction of received beacon signal. An array of tracking antenna elements (18) generates output signal in response to beacon signal, reflected from a parabolic reflector antenna (14). The parabolic reflector antenna is positioned on a space craft (12) to receive the signal from the beacon located on the ground. The tracking array of antenna elements are oriented selective to the reflector antenna. The tracking control receiver converts an amplitude and phase of each tracking antenna into respective i' and q' terms and computes dot product of each i' and q' term and each reference response vector. If the dot product is maximum, the direction of received beacon signal is determined to be the direction of a reference grid. The tracking control receiver generates a steering control voltage for use by a space craft control system in response to the determined direction of the received beacon signal. An independent claim is also included for digital antenna tracking method.