Evaluation of strategies for the ultra-rapid orbit prediction of BDS GEO satellites

ABSTRACT

The quality of BeiDou Navigation Satellite System (BDS) Geostationary Earth Orbit (GEO) ultra-rapid products is unsatisfactory because GEO satellites are nearly stationary relative to ground stations. To optimize the quality of these ultra-rapid orbit products, we investigated the effects of the fitting arc length, an a priori Solar-Radiation Pressure (SRP) model, and the along-track empirical acceleration on the prediction of BDS GEO satellite orbits. The predicted orbit arcs of 24-h were evaluated through comparisons with the corresponding observed orbit arc and Satellite Laser Ranging (SLR) observations. In both eclipse and non-eclipse seasons, accuracy of the orbit predictions obtained using a 48-h fitting arc length were better than those obtained using 24-h and 72-h fitting arc lengths. Although the overlapping precision of predicted orbits exhibited no obvious improvement when an a priori SRP model was employed, the systematic bias in the SLR residuals was significantly reduced. Specifically, the mean value of SLR residuals decreased from −0.248 m to −0.024 m during non-eclipse seasons and from −0.333 m to −0.041 m during eclipse seasons, respectively. In addition, when an empirical acceleration in the along-track direction was introduced, the three-Dimensional Root-Mean-Square (3D RMS) of overlapping orbits during eclipse seasons decreased from 2.964 to 1.080 m, which is comparable to that during non-eclipse seasons. Furthermore, the Standard Deviation (STD) of SLR residuals decreased from 0.419 to 0.221 m during eclipse seasons. The analysis of SRP estimates shows that the stability of SRP parameters was significantly enhanced after the introduction of along-track empirical acceleration in eclipse seasons. The optimal BDS GEO ultra-rapid orbit prediction products were yielded by using a 48-h fitting arc length, an a priori SRP model and an along-track empirical acceleration.

KEYWORDS:

• BDS GEO satellites
• orbit prediction
• solar radiation pressure model

Acknowledgments

The experiment data are collected from the MGEX, iGMAS networks. The numerical calculations in this paper have been done on the supercomputing system in the Supercomputing Center of Wuhan University.

Data available

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant number:41904021].

Notes on contributors

Wenxi Zhao

Xiaolei Dai is currently an associate professor at Wuhan University. She received her Ph.D. degree from Wuhan University in 2016. Her current research interests are real-time precise orbit determination and clock estimation of GNSS, orbit attitude and force modeling for BDS and real-time data processing in the RTS system.

Xiaolei Dai

Wenxi Zhao is currently a postgraduate in GNSS Research Center, Wuhan University. Her area of research currently focuses on real-time GNSS orbit determination.

Yidong Lou

Yidong Lou is currently a professor at GNSS Research Center, Wuhan University. He received his Ph.D. in Geodesy and Surveying Engineering from the Wuhan University in 2008. His current research interest is in the real-time precise GNSS orbit determination and real-time GNSS PPP.

Yaquan Peng

Yaquan Peng is currently a Ph.D. candidate in GNSS Research Center, Wuhan University. His area of research currently focuses on multi-GNSS orbit determination.

Xueyong Xu

Xueyong Xu is a professorate senior engineer in North Information Control Research Academy Group Co. Ltd. China. He received his Ph.D. degree from University of Science and Technology of China. His current research focus on high-precision GNSS applications.