Toward Single-epoch 10-centimeter Precise Point Positioning using Galileo E1/E5a and E6 Signals

Jiang Guo and Shaoming Xin

Abstract: Emerging applications such as autonomous driving have greatly promoted innovations in GNSS positioning algorithms. It is highly expected that GNSS should provide instantaneously, without any latency or convergence, a better than 20 cm positioning accuracy in real time to satisfy the critical requirements by self-driving vehicles for highly strict safety standards. In this case, we developed a precise point positioning wide-lane ambiguity resolution (PPP-WAR) method with the goal of achieving 10-cm positioning accuracy in the horizontal component using only a single epoch of Galileo E1/E5a and E6 signals. Other GNSS constellations such as GPS/BeiDou/QZSS were also coupled tightly with Galileo to further improve PPP-WAR efficiency. To form inter-GNSS resolvable ambiguities, we firstly calculated station-specific inter-system phase biases (ISPBs) for two wide-lane phase observables, and then inter-system fractional-cycle biases (FCB) were computed to recover the integer nature of those wide-lane ambiguities. We used multi-GNSS data from 31 stations over 31 days to validate this method. We found that 93% day-to-day variations of both wide-lane ISPBs stayed within ? 0.1 cycles. Besides, FCB estimates were also quite stable with a standard deviation of less than 0.03 cycles. With these phase bias corrections, we achieved a mean instantaneous positioning accuracy of 0.13 m, 0.11 m and 0.37 m for the east, north and up components, respectively, in case of Galileo/GPS/BeiDou/QZSS PPP-WAR solutions. More interestingly, a comparable positioning accuracy of 0.12 m, 0.10 m, 0.42 m could also be reached with only a single epoch of Galileo-only E1/E5a and E6 signals when there were more than 9 satellites. We note that Galileo E1/E5a/E6 signals outperform E1/E5a/E5b in enabling PPP-WAR to achieve a 10-centimeter positioning accuracy. We carried out a vehicle-borne test and achieved a positioning accuracy of 0.19 m, 0.21 m, 0.61 m for Galileo-only PPP-WAR, though the number of visible satellites was less than 7 during the experiment. Therefore, we can envision that the full Galileo constellation in the near future may be promising to enable a sub-decimeter-level instantaneous PPP-WAR service on a global scale to support autonomous driving.
Published in: Proceedings of the 32nd International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2019)
September 16 - 20, 2019
Hyatt Regency Miami
Miami, Florida
Pages: 2870 - 2887
Cite this article: Guo, Jiang, Xin, Shaoming, "Toward Single-epoch 10-centimeter Precise Point Positioning using Galileo E1/E5a and E6 Signals," Proceedings of the 32nd International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2019), Miami, Florida, September 2019, pp. 2870-2887.
https://doi.org/10.33012/2019.16925
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