Star sensor based spacecraft angular rate estimation independent of attitude determination

A star sensor based new method for estimation of satellite angular rates through derivative approach is proposed. The method is based on “optic flow” of star image patterns formed on a star sensor array. The satellite angular rates are derived directly from the 2D-coordinates of star images. Therefore, the proposed algorithm is computationally efficient in the category of vector derivative approach, where there is no need for star identification. The noisy character of estimated angular rates is alleviated by employing a simple linear time invariant Kalman Filter.