Effect of Dynamic Model of Satellite on accuracy of Attitude Estimation with Unknown Star Sensor Noise Level

In this paper we will design an interacting multiple models adaptive attitude estimator (IMMAE) for a satellite with unknown star sensor noise level. This algorithm will be designed once using only kinematic model of the satellite which will be entitled 6-state IMMAE method and once using kinematic and dynamic models of the satellite which will be entitled 12-state IMMAE method. The results will be compared to illustrate the effect of dynamic model of satellite on accuracy of attitude estimation through numerical simulations. We have shown that although the 12-state IMMAE method can not estimate the attitude of the satellite accurately at the beginning of the maneuvers; however, it improves the accuracy of the attitude estimation about %20 in comparison with applying the 6- state IMMAE method at the end of maneuvers in the presence of star sensor measurement noise level changes. In this method, high fidelity gyro and star sensor models are used to evaluate the design in realistic situation associated with gyro errors and star sensor noise level uncertainties.