Autonomous Navigation of Satellite Constellation using Attitude Sensors and Cross-link Measurement
- Paper number
IAC-08.C1.4.9
- Author
Mr. Chunling Wei, China
- Year
2008
- Abstract
Autonomous navigation of satellite constellation can significantly decrease ground maintenance cost and improve autonomy ability. An autonomous navigation system using attitude sensors and cross-link measurement is studied in this paper. The involved attitude sensors include imaging earth sensor, star sensor and gyroscopes. The inter-satellite cross-link is used not only for communication or information exchange but also for obtaining the pseudo-range measurement between neighbor satellites among the constellation.
The autonomous navigation method using earth sensor and star sensor is a classical optical scheme, and the measurement input into the navigation filter is the direction vector of earth center in inertial coordinate frame. The earth sensor works in ultraviolet spectrum, and provides the coordinates of earth center in CCD frame, which is related to pitch and roll angles of the satellite, and radius of the image, which can be used to derive the orbit altitude. The star sensor and gyros are used to determine the inertial attitude of the satellite, and can attain arc-sec level accuracy.
According to the accuracy of state-of-the-art attitude sensors, the performance of autonomous navigation is dominated by the earth sensor and some systematic errors, such as misalignment and measurement bias. For satellite constellation, an integrated navigation scheme based on attitude sensors and cross-link measurement is proposed and validated through numerical simulation. The pseudo-range measurement uncertainty due to radio frequency cross-link is assumed to be 3m (3 σ). A distributed navigation filter is designed to adapt the constellation scenario.
Unit direction vector measurement error is also treated as state parameters and expanded into the navigation filter, after observability analysis of the systematic bias. In comparison with autonomous navigation methods in the literature, this paper stresses on-board calibration of systematic errors by using cross-link measurement and distributed filter architecture for autonomous navigation of satellite constellations
- Abstract document
- Manuscript document
(absent)