Comparison of different stochastic orbit modeling techniques

Reduced-dynamic orbit determination for spaceborne GPS receivers is a method promising highest accuracy of the estimated LEO trajectories. We compare the performance of different pseudo-stochastic orbit parametrizations (instantaneous velocity changes and piecewise constant accelerations) and probe the range between dynamic and heavily reduced dynamic orbits. Internal indicators like formal accuracies of orbit positions, comparisons with orbits computed at the Technical University of Munich (TUM), and validations with SLR measurements are used to assess the quality of the estimated orbits. For piecewise constant accelerations comparisons between the estimated and the measured accelerations from the STAR accelerometer allow for an additional and independent validation of the estimated orbits.