APS star tracker and attitude estimation

Star tracker is an important component in the spacecraft attitude determination system. With the small satellite development, the traditional CCD star tracker could not meet the requirement in the mass, power consumption, and volume, The AFS CMOS based Autonomous Star Tracker (AAST) has been proposed recently. The star tracker contains digital image processing unite and attitude algorithm processing unite so that it can perform ali the functions without external support and provide 3-axis attitude information directly. In this paper, the star tracker prototype is introduced. The design concept of the optics and electronics contribute to the construction of a low mass (1kg), low power (2W), high rate (5Hz) and inexpensive autonomous star tracker. This paper also introduces a multi-vectors attitude determination method which has a simple fixed iterated initial value and at most two times iteration, A novel method is proposed an this paper for the star tracker performances testing, especially for the validation of Lost-In-Space star identification and attitude determination algorithms. The performances of the star tracker prototype have been verified through the real night sky experiments using this method