A filtering algorithm for trajectory target in free section based on MM-UKF

In order to improve accuracy of filtering of trajectory in free phase, a filtering algorithm of the trajectory in free phase is proposed based on MM-UKF. First, under the framework of UKF filtering, trajectory in free phase model with amendments J2 is introduced and its expression is derived; then, in order to ensure accuracy and robustness of filter simultaneously, the multiple-model algorithm is involved within the framework of UKF; finally, a complete filtering process is proposed. Simulation results show that, compared with the traditional EKF and UKF algorithms, this algorithm have an advantage in filtering accuracy and convergence rate.