When it comes to satellites, not only are the exact whereabouts and the orbit important but also the attitude, in other words the orientation of the satellite.
Without knowing the attitude it’s impossible to turn the solar cells towards the Sun, the cameras towards the objects to be observed, and the antennas towards to the transmitter or the receiver.
Within the framework of the thesis, the task was to propose and implement a Star Tracker algorithm for satellites, which is able to successfully determine the satellite’s attitude, based on photos of the stars.
The thesis describes the coordinate systems used by Star Trackers, the structure of the software, the specifications, and the possible realizations of its different parts.
The algorithms to identify stars are presented and compared. The design and implementation of a prototype in MATLAB is described.
After implementing and testing the prototype, the Star Tracker software was also implemented in C, which is required for running it on a microcontroller placed on a satellite. The thesis shows the main differences between the prototype and the software written in C, and explains the reasons for them.
The final part of the thesis presents the testing of the algorithm on both real and synthetic photos, and the evaluation of the results.