Roll Angle Measurement Research Articles

Onboard spin axis controller for a geostationary spin-stabilized satellite

Design and performance of an onboard system for precision control of the spin axis attitude of either spinor dual-spin-stabilized geostationary satellites is presented in this paper. The spin axis controller uses the output of a spinning Earth horizon sensor to derive onboard real-time estimates of the spin axis roll and yaw attitude errors and Earth sensor bias. The Earth sensor directly provides the spacecraft roll angle measurement, while the Earth orbit kinematic coupling is used to derive the spacecraft yaw angle of sensor bias information. Maneuver logic uses these attitude error data to implement a simple control scheme that spin synchronously pulse fires a single axial thruster, providing for complete roll and yaw control of the spacecraft attitude. The proposed system provides substantially increased spacecraft autonomy and significantly reduces operational loads and the costs of the ground control station. The system also provides high spin axis pointing accuracy in the presence of severe attitude precession rates. The spin axis controller system is currently being implemented on the Intelsat VI communication satellite.