Extended Kalman filter for attitude determination of an elliptical orbit satellites

This paper investigates the influence of the orbit eccentricity on the performance of the attitude determination and control subsystem (ADCS) pointing of passive Low Earth Orbit (LEO) satellites stabilized by a gravity gradient boom. The contribution of this work is twofold. First, satellite attitude dynamics and kinematics are modeled by introducing the orbit eccentricity in the equations of motion of a LEO satellite in order to provide the best scenarios in which satellite operators can keep the nominal functionality of LEO satellites with a gravity gradient boom. Second, a Quaternion-based Extended Kalman Filter (EKF) is analyzed when the orbit eccentricity is considered in order to determine the influence of this disturbance on the convergence and stability of the filter. The simulations in this work are based on the real parameters of ALSAT-1 which is a typical LEO satellite stabilized by a gravity gradient boom. The obtained results show that the orbit eccentricity has a big influence on the pointing system accuracy by causing micro-vibrations that affect the geocentric pointing.