GPS-based attitude determination of gyrostat satellite by quaternion estimation algorithms

The theoretical methodologies and numerical results of quaternion estimation (QUEST) algorithms for the GPS-based attitude determination of a low earth orbit gyrostat satellite are presented. The attitude tumbling of the gyrostat satellite is suppressed with the proposed linear regulators. The numerical techniques for the generation of angular velocities of the gyrostat satellite and the determination of the attitude are investigated. As comparison, we formulated the process and observation models for the Kalman filtering algorithms. The simulation results indicate that QUEST algorithms can be employed to estimate the attitude of the gyrostat satellite point-by-point accurately, when combined with the GPS phase difference signals. The simulation also shows that the results from QUEST algorithms are of the same amplitude in accuracies as the results from the Kalman filtering algorithms. Under the appropriate assumption of measurement noises at the GPS phase difference signal, the precision of the attitude estimates is assessed to be at the level of 0.5degrees for the attitude motions of the gyrostat satellite. The results from the theoretical simulation in this paper can be used to validate the algorithms of the integer offset time biases and the assumption of line-of-sight measurement noises and the baseline-calibration. (C) 2002 Elsevier Science Ltd. All rights reserved.