Abstract: Tracking of collocated satellites is accomplished by providing a single tracking antenna having a tracking feed and combiner which receives a first satellite signal. A first pointing error signal is extracted from the tracking feed based on the first satellite signal and the antenna is steered to a pointing angle to minimize the first pointing error signal. A second satellite signal is received and a second pointing error signal is extracted from the tracking feed based on the second satellite signal. An offset angle for the second satellite is then calculated from the second pointing error signal relative to the pointing angle of the antenna. Orbit estimation and can then be accomplished for the second satellite based on the offset angle directly or by conversion to an absolute angle.