Performance Assessment for Combined GPS and BDS Real-time Precise Point Positioning in the Coastal Region of Bohai Gulf, China

Abstract

Qu, L.; Huang, H.; Du, M., and Acharya, T.D., 2019. Performance assessment for combined GPS and BDS real-time precise point positioning in the coastal region of Bohai Gulf, China. In: Lee, J.L.; Yoon, J.-S.; Cho, W.C.; Muin, M., and Lee, J. (eds.), The 3rd International Water Safety Symposium. Journal of Coastal Research, Special Issue No. 91, pp. 271-275. Coconut Creek (Florida), ISSN 0749-0208.In this study, we focus on the performance assessment of combined Global Positioning System (GPS) and BeiDou Navigation Satellite System (BDS) real-time Precise Point Positioning (PPP) in the coastal region of Bohai Gulf, China. Firstly, 120 Global Navigation Satellite System (GNSS) stations from Multi-GNSS Experiment (MGEX) network of the International GNSS Service (IGS) were processed to generate ultra-rapid precise orbit of both GPS and BDS satellites, updated with the interval of three hours. Secondly, real-time precise satellite clock errors were estimated to compensate the orbit error with 24 regional stations from Crustal Monitor of Network of China (CMONOC) and MGEX networks. Finally, with those products, the performances of GPS-only, BDS-only and combined GPS and BDS real-time PPP were compared and evaluated. The experimental result illustrated that the ultra-rapid orbit accuracy of BDS-2 satellites was still worse than that of GPS satellites which was sub-decimeter level. Among three types of orbital satellites of BDS-2, the orbital accuracy of medium Earth orbit (MEO) and inclined geosynchronous orbit (IGSO) satellites were at decimeter level while for geostationary Earth orbit (GEO) satellites was at meter-level. The MEO satellites had the best accuracy while the GEO satellites performed the worst. In addition, the 3D accuracy of BDS-only real-time PPP was 10 cm better. Although the accuracy of BDS-2 real-time PPP was still worse than that of GPS and more time was taken for convergence. By adding BDS on top of GPS, the accuracy in the east, north and up components improved 40.0%, 33.3% and 18.5%, respectively, and the convergence time reduced 36.3%, 15.4% and 58.3%, respectively compared to the GPS only.