Spacecraft Attitude Rate Determination from Star Trackers Based on Spatial Velocimeter

Abstract

This paper proposes a method to detect spacecraft attitude rate without rate gyros. In this method, a spatial velocimeter is applied to images acquired by a star tracker (STT), where a spatial velocimeter is normally used to detect object velocities from optical image data. The proposed method requires no priori attitude states or identification of STT acquired images. Therefore, it is directly useful for attitude rate determination right after orbit injection even when the attitude rate is relatively large.