With the technical development of the communication satellites and the wide application of multibeam antennas,antenna pointing control problem is becoming increasingly important. The traditional pointing measurement utilizesseveral beams, which occupies lots of satellite resources. In this paper, a maximum likelihood estimation of theantenna pointing based on communication beams is proposed, which reduce the antenna pointing measurementrequirements on satellite. The estimation performance is analyzed which gives the pointing measurement precisionand error distribution. The pointing error is composed of calibration error and estimation error, while the pointingerror follows normal distribution. Simulation results show that the precision improvement slows down due to thecalibration error when SNR is greater than 20dB, and the worst precision is better than 0.1°(3σ). Moreover, theperformance is largely affected by channel stability when the uncertainty is greater than 1dB(σ) in our simulation.Considering the effects on pointing measurement accuracy of the channel stability, an improved robust method isgiven in our discussion. It utilizes another beacon beam to calibrate the pointing measurement results, which caneliminate the performance descent due to the channel uncertainty. Simulation shows that this improved method isinsensitive to the channel stability and can provide a stable pointing measurement performance similar to thetraditional method.
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