Autonomous satellite orbit determination using spaceborne GNSS receivers

The influence of outer space conditions on the navigation-processing algorithms has been analyzed. The main problems that need to be solved by researchers in developing procedures for digital signal processing in onboard satellite navigation equipment have been described. It has been shown that navigation accuracy depends on the quality of the models for satellite motion and the onboard clock. It has been pro-posed that the stochastic “random walk” model based on the Kalman filter should be used for clock modeling. It has been demonstrated that this model is much more efficient than the classical polynomial model for GEO satellite navigation. Together with the precise satellite dynamic model, it allows three-dimensional accuracy on the order of 30 m, even in the case when a standard temperature-compensated crystal oscillator is used.