초록 ▼

Agile (electronically steerable) beam sensing with associated on-board processing, previously used exclusively for positioning of antennas for beam formation and tracking in communications systems, is now also used for satellite active attitude determination and control. A spinning satellite (100) i

Agile (electronically steerable) beam sensing with associated on-board processing, previously used exclusively for positioning of antennas for beam formation and tracking in communications systems, is now also used for satellite active attitude determination and control. A spinning satellite (100) is nadir oriented and precessed at orbit rate using magnetic torquing determined through use of an on-board stored magnetic field model (520) and attitude and orbit estimates (212). A Kalman filter (211) predicts parameters (202, 203) associated with a received signal (204) impinging on the satellite\s wide angle beam antenna (201). The antenna system measures the error between the parameter predictions and observed values and sends appropriate error signals (207) to the Kalman filter for updating its estimation procedures. The Kalman filter additionally outputs the spacecraft attitude error signals (215) to an attitude control law (213), which determines commands to attitude-altering magnetic torque elements (220) to close the control loop via the spacecraft dynamics (230).

대표청구항 ▼

An on-board attitude determination system for a spacecraft orbiting a celestial body comprising: means for estimating the orbit and attitude of the spacecraft relative to a plurality of remote sources of coherent energy signals; an agile beam sensor sensing the locations of the remote sources; means

An on-board attitude determination system for a spacecraft orbiting a celestial body comprising: means for estimating the orbit and attitude of the spacecraft relative to a plurality of remote sources of coherent energy signals; an agile beam sensor sensing the locations of the remote sources; means for pointing the agile beam sensor at the estimated relative locations of the remote sources; means for determining error signals representative of the difference between the estimated locations of the remote sources and actual locations of the remote sources as sensed by the agile beam sensor; and said estimating means being adapted to receive said error signals and update the predicted orbit and attitude of the spacecraft.