High Update Rate Star Tracker for Gyroless Spacecraft Operation

Abstract

Traditional star trackers are designed for high accuracy but low update rate and rely on rate gyros to interpolate between measurements. However, the available rate gyros are either noisy, or expensive and heavy. The proposed work demonstrates the advantage of sacrificing some of the star tracker's accuracy for a higher update rate. As a result, aside from removing the need for a rate gyro, Attitude Determination and Control Systems overall performances are increased. The proposed star tracker achieved a 0.001 ° accurate Attitude Determination, with a 98.8% sky coverage at a 50Hz update rate. In addition, the image processing and star matching algorithm are designed to be efficiently implemented as a fully pipelined single-pass FPGA circuit.