Evaluation and Analysis of Orbit Determination Accuracy of BDS Satellite Under Clock Offset Constraint

Abstract

High-precision satellite orbit determination is the premise for the satellite navigation system to achieve high-performance services. The BDS improves the accuracy of orbit determination through the use of inter-satellite link (ISL) observation data, and realizes the rapid orbit recovery after satellite maneuvering with the support of satellite-earth bidirectional time synchronization data. Based on BDS 18 MEO, 1 IGSO and 1 GEO satellites, the satellite orbit determination under clock constraint, use the ISL, and use only satellite-earth observation data by data from nine tracking stations in China were used. And the orbit errors and orbit prediction accuracy of the three orbit determination method are analyzed. Two high orbit satellites were tested for orbit determination during recovery after maneuvering, and the precision of orbit determination during recovery was evaluated. The results show that: for the BDS satellite orbit determination under the constraint of clock error, the position error RMS of the overlapping orbit is 1.25 m, and the predicted 24-h orbit position deviation is 2.12 m. Compared with the combined orbit determination results of the ISL data, the IGSO/MEO satellite orbit URE is 0.29 m, while the GEO satellite has an orbit deviation exceeding 10 m in tangential direction. The satellite orbit determination method under the constraint of clock offset can realize the rapid orbit recovery after the maneuver of BDS satellite. The apparent direction accuracy of the two BDS high-orbit satellites within 4 h after the maneuver is better than 0.5 m, and the orbit URE is better than 0.75 m.