2009 年 7 巻 ists26 号 p. Pd_63-Pd_68
In Space Systems Dynamics Laboratory at Kyushu University, the mini-satellite QSAT is being developed. This satellite aims at investigating the plasma physics in the aurora zone in order to better understand spacecraft charging and at conducting a comparison of Field-Aligned-Currents observed in orbit with ground-based observations. In order to achieve the mission objectives, the spacecraft attitude must be determined. The attitude determination concept of QSAT is based on a combination of the Weighted-Least-Square and Linearized-Kalman filter estimation methods. The Weighted-Least-Square method produces the optimal attitude-angle observations at one point in time by using the Sun sensor and magnetometer measurements. The recursive Linearized-Kalman filter combines the angular observations with the attitude rate measured by the gyros to produce the optimal attitude solution.