Attitude estimation for a bias-momentum geosynchronous satellite using an adaptive observer

Attitude estimation for a bias momentum geosynchronous satellite is investigated using a modification of the adaptive observer technique developed by Kreisselmeier. The unknown parameters are taken to be the offsets of the angular momentum vector along the roll and yaw axes. The results are compared with those obtained using a Luenberger observer. The modified adaptive observer gives good estimates for roll, roll rate, and pitch rate only. It is suggested that this is due to the low degree of observability of the yaw angle and yaw rate of this system.