Development of star tracker system for accurate estimation of spacecraft attitude

Abstract

This thesis researches different star pattern recognition and attitude determination algorithms for a three-axis rotational spacecraft. A simulated star field will be suspended above the experimental Three-Axis Spacecraft simulator to proved a reference for the star-pattern recognition algorithms. A star field inertial reference frame database of stars will be developed with the simulator at zero attitude. The angle, planar triangle and spherical triangle star patter recongition algorithms will then be used to identify which stars are within a camera's field of vision. The imaged stars will then be matched up to the corresponding stars within the test bed database. With the imaged stars identified and the corresponding inertial frame reference data, the test bed's attitude will be determined using the least-squares, TRIAD, and Quaternion Estimator (QUEST) attitude determination algorithms. On the three-axis simulator, an iterative algorithm is developed to demonstrate increasing star tracker accuracy with each update A matrix.