PPP augmentation and real-time precise orbit determination for LEO satellites

It is valuable for ground users to realize centimeter-level positioning based on PPP. However, the initialization of PPP algorithm costs a long time, which limits its application. In order to achieve the near-real-time PPP positioning for users, an augmentation scheme by utilizing LEO satellite is proposed so as to improve the initialization speed of PPP solver. And then, the real-time orbit determination method with high-precision by utilizing a PPP pre-processing procedure is investigated to achieve the real-time orbit determination for LEO satellites at centimeter-level, and the orbit determination model and processing algorithm are designed. STK, GPS simulator, high dynamical GPS receiver, navigation augmentation equipment and the processing software are utilized to carry out the experimental verification. The experimental results show that, the real-time orbit determination software works correctly, the accuracy of orbit determination is better than 0.05 m, and the position and velocity prediction errors are less than 0.15 m and 0.018 cm/s in 15 minutes.