Computing the installation error between star tracker and Fiber Optic Gyroscope

Star tracker is one of the most important devices used on satellites for attitude determination. Since its output is discontinuous, it needs to be aided to complement its discontinuity. Using gyroscope unit is the most suitable choice for aiding the star tracker. However, using these two kinds of sensor simultaneously has some challenges. In other words, not only biases lead to low accuracy in the attitude determination, but also the installation error has a significant effect on the accuracy. In this paper after presenting the important role of installation errors between star tracker and gyroscope in the accuracy of attitude determination, an effective method is proposed to determine the misalignment error between these two sensors which is based only on their measurements, and the mathematical formulation is presented in detail. Then, to validate the performance of the proposed method, it is implemented to calculate the instantiation error of an experimental dataset gathered in the Mount Pooladkaf, for which the results are reported.