WSEAS Transactions on Systems
Print ISSN: 1109-2777, E-ISSN: 2224-2678
Volume 12, 2013
The Brazilian Autonomous Star Tracker - AST
Authors: , , , ,
Abstract: The main subject of this paper is the star tracker system called AST (autonomous star tracker), currently under development at the Brazilian National Institute for Space Research – INPE. A description of the approach used to estimate the attitude on board the spacecraft, in real time and autonomously, is presented. The methods and techniques described in this paper guided the creation of the embedded software of the instrument in what concerns the attitude estimation and tracking. In it, a pattern recognition procedure is employed to identify stars in the field of view (FOV) of an active pixel sensor (CMOS APS), which comprises a star sensor system of one fixed head. As results, two computer program packages were created. The first one is intended to control the star tracker system operation, and the other is a simulation environment to test the system operation. This simulator environment was called ADAST (Attitude Determination Algorithm Software Test) and it represents an important contribution to the sector, for it comprises a complete simulation environment of a star sensor/tracker system, to be used in both, the understanding of the fundamentals of this equipment operation, and in the design and testing of algorithms that make up the system. The part of the studies concerning the search and track operations, along with their results, are discussed and presented in this paper. Some tests of the AST system are scheduled and are also described. Once tested, the AST will integrate the attitude control system of future Brazilian satellites within the goals of the space program in progress.