Attitude Change Rate Estimation from Multi-Head Star Sensor Images

Abstract

For a star sensor to be autonomous, it must detect the attitude change rate of a spacecraft, i.e., the body rate, even when it is high. In this paper, we propose a body rate estimation method from multi-head star sensor images based on a maximum likelihood method in a frequency domain. In a previous work, we showed that body rate could be estimated from star sensor images in a frequency domain. That was, however, for a one head star sensor case, and since the field of view of the star sensor head is narrow, the estimation accuracy of the component of the body rate vector parallel to the head's optical axis was low. In this paper, we extend the method to a multi-head star sensor case and show that sufficient estimation accuracy is obtained from the proposed method.