Abstract: To accurately address the orbit motion of small satellites in low Earth orbit, a kind of high-precision orbital propagation algorithm and on-orbit thrust calibration algorithm based on the consideration of complex perturbation forces were designed. Firstly, the dynamic model for small satellites was established considering the gravitational force of the sphere Earth and several perturbations. The variable-step Runge-Kutta integrator was employed in the orbit propagation. Then, using the unscented kalman filter (UKF), an on-orbit calibration algorithm was designed to calibrate the micro-thrust with errors in real time. To validate the effectiveness and accuracy of the proposed orbit prediction method, its results were compared with those of STK programs in a great number of simulation scenarios. The numerical simulation shows that the joint orbit determination and electric thrust calibration are quite precise.

Key words: microthrust, complex perturbation, orbital propagation, thrust calibration, unscented kalman filter (UKF)