A Rigorous Orbit Attitude Estimation Algorithm for Low-Earth-Orbit Spacecrafts

In this paper, a rigorous orbit attitude estimation algorithm for low-Earth-orbit (LEO) spacecrafts is presented in the presence of earth oblateness and atmospheric drag. The spacecraft orbit attitude kinematics for arbitrary eccentric orbit is derived. The variational orbit angular velocity is computed using the inertial position and velocity. The effects of the orbit estimation precision with respect to orbit attitude determination are analyzed. An extended Kalman filter (EKF) is derived to estimate the orbit attitude, inertial position and velocity, as well as gyro bias. Simulation results indicate that the proposed algorithm has better estimation performance for the orbit attitude over than the traditional algorithm.