Abstract: Aimed at the problem that the efficiency of reduced dynamic orbit determination(OD) for LEOs became lower and lower as the piece-wise dynamic parameters increased, an efficient algorithm, which was based on parameter transforming was proposed and a set of formulas were deduced theoretically. Using the efficient algorithm, the LEOs' OD was realized and the performance was improved efficiently. An experiment that nine parameters' empirical force model and pseudo stochastic pulse model were used to smooth GRACE-B's precise orbit respectively was performed. The result shows that the RMS in R, T and N is less than 0.004 m. In the way of efficiency, the improvement of nine parameters' empirical force model is not distinct, but compared to the traditional algorithm, the time consumed by the efficient algorithm is saved about 69%. Another reduced dynamic OD experiment is performed by using nine parameters' empirical force model and pseudo stochastic pulse model. The result shows that the RMS in R, T and N reachs 0.02 m. In the way of efficiency, compared to the traditional algorithm, the time consumed is saved about 21% in the former and 78% in the latter by the efficient algorithm.

Key words: pseudo stochastic pulse, empirical force model, parameter transforming, orbit determination, efficient algorithm