Simplified Filtering Estimator for Spacecraft Attitude Determination From Phase Information of GPS Signals
This paper presents an implementation of a simplified filtering estimator for satellite attitude determination using GPS (Global Positioning System) signals. The non-linear system of estimator was modelled using Euler angles parameterisation which applicable for real-time operation onboard-satellite. An approach was to keep a pitch state independent of roll and yaw. In order to cope with spacecraft dynamics, the moment of inertial tensor of spacecraft and torques caused by Earth's gravitation field were modelled to estimate the rate of change of angular velocity. Other advantage of the simplified filtering estimator was that the electrical path difference, line bias, between antenna chains caused an offset error in GPS measurements can be estimated. The developed filtering estimator was testing through simulated data, and flight data from real spacecraft.