GPS Solutions

, 22:26 | Cite as

Undifferenced ionospheric-free ambiguity resolution using GLONASS data from inhomogeneous stations

  • Qile Zhao
  • Xiaotao Li
  • Yang Liu
  • Jianghui Geng
  • Jingnan Liu
Original Article
  • 254 Downloads

Abstract

GLONASS frequency division multiple access signals render ambiguity resolution (AR) rather difficult because: (1) Different wavelengths are used by different satellites, and (2) pseudorange inter-frequency biases (IFBs) cannot be precisely modeled by means of a simple function. In this study, an AR approach based on the ionospheric-free combination with a wavelength of about 5.3 cm is assessed for GLONASS precise point positioning (PPP). This approach simplifies GLONASS AR because pseudorange IFBs do not matter, and PPP-AR can be enabled across inhomogeneous receivers. One month of GLONASS data from 165 European stations were processed for different network size and different durations of observation periods. We find that 89.9% of the fractional parts of ionospheric-free ambiguities agree well within ± 0.15 cycles for a small network (radius = 500 km), while 77.6% for a large network (radius = 2000 km). In case of the 3-hourly GLONASS-only static PPP solutions for the small network, reliable AR can be achieved where the number of fixed GLONASS ambiguities account for 97.6% within all candidate ambiguities. Meanwhile, the RMS of the east, north and up components with respect to daily solutions is improved from 1.0, 0.6, 1.2 cm to 0.4, 0.4, 1.1 cm, respectively. When GPS PPP-AR is carried out simultaneously, the positioning performance can be improved significantly such that the GLONASS ambiguity fixing rate rises from 74.4 to 95.4% in case of hourly solutions. Finally, we introduce ambiguity-fixed GLONASS orbits to re-attempt GLONASS PPP-AR in contrast to the above solutions with ambiguity-float orbits. We find that ambiguity-fixed orbits lead to clearly better agreement among ionospheric-free ambiguity fractional parts in case of the large network, that is 80.5% of fractional parts fall in ± 0.15 cycles in contrast to 74.6% for the ambiguity-float orbits. We conclude that highly efficient GLONASS ionospheric-free PPP-AR is achievable in case of a few hours of data when GPS PPP-AR is also accomplished, and ambiguity-fixed GLONASS orbits will contribute significantly to PPP-AR over wide areas.

Keywords

Precise point positioning GLONASS Ionospheric-free ambiguity resolution Fractional-cycle bias Inhomogeneous stations 

Notes

Acknowledgements

This work is funded by National key R&D plan on strategic international scientific and technological innovation cooperation special project (2016YFE0202300) and National Science Foundation of China (41674033) and State Key Research and Development Programme (2016YFB0501802). We would like to thank IGS and ESA for data and products. The Super Computing Facility at Wuhan University contributes to this study greatly.

References

  1. Al-Shaery A, Zhang S, Rizos C (2013) An enhanced calibration method of GLONASS inter-channel bias for GNSS RTK. GPS Solut 17(2):165–173CrossRefGoogle Scholar
  2. Banville S (2016) GLONASS ionosphere-free ambiguity resolution for precise point positioning. J Geod 90(5):487–496CrossRefGoogle Scholar
  3. Bertiger W, Desai SD, Haines B, Harvey N, Moore AW, Owen S, Weiss JP (2010) Single receiver phase ambiguity resolution with GPS data. J Geod 84(5):327–337CrossRefGoogle Scholar
  4. Boehm J, Werl B, Schuh H (2006) Troposphere mapping functions for GPS and very long baseline interferometry from European Centre for Medium-Range Weather Forecasts operational analysis data. J Geophys Res.  https://doi.org/10.1029/2005JB003629 Google Scholar
  5. Cheng S, Wang J, Peng W (2017) Statistical analysis and quality control for GPS fractional cycle bias and integer recovery clock estimation with raw and combined observation models. Adv Space Res.  https://doi.org/10.1016/j.asr.2017.06.053 Google Scholar
  6. Collins P, Bisnath S, Lahaye F, Héroux P (2010) Undifferenced GPS ambiguity resolution using the decoupled clock model and ambiguity datum fixing. Navigation 57(2):123–135CrossRefGoogle Scholar
  7. Dach R, Schmid R, Schmitz M, Thaller D, Schaer S, Lutz S, Steigenberger P, Wubbena G, Beutler G (2011) Improved antenna phase center models for GLONASS. GPS Solut 15(1):49–65CrossRefGoogle Scholar
  8. Dai L (2000) Dual-frequency GPSGLONASS real-time ambiguity resolution for medium-range kinematic positioning. In: ION GPS 2000, 19–22 Sept 2000, Salt Lake City, pp 1071–1080Google Scholar
  9. De Jonge P, Tiberius C (1996) The LAMBDA method for integer ambiguity estimation: implementation aspects. Publications of the Delft Computing Centre, LGR-Series 12Google Scholar
  10. Ge M, Gendt G, Rothacher M, Shi C, Liu J (2008) Resolution of GPS carrier-phase ambiguities in precise point positioning (PPP) with daily observations. J Geod 82(7):389–399CrossRefGoogle Scholar
  11. Geng J, Bock Y (2016) GLONASS fractional-cycle bias estimation across inhomogeneous receivers for PPP ambiguity resolution. J Geod 90(4):379–396CrossRefGoogle Scholar
  12. Geng J, Shi C (2017) Rapid initialization of real-time PPP by resolving undifferenced GPS and GLONASS ambiguities simultaneously. J Geod 91(4):361–374CrossRefGoogle Scholar
  13. Geng J, Meng X, Dodson A, Teferle F (2010a) Integer ambiguity resolution in precise point positioning: method comparison. J Geod 84(9):569–581CrossRefGoogle Scholar
  14. Geng J, Meng X, Teferle FN, Dodson AH (2010b) Performance of precise point positioning with ambiguity resolution for 1- to 4-h observation periods. Surv Rev 42(316):155–165CrossRefGoogle Scholar
  15. Geng J, Shi C, Ge M, Dodson AH, Lou Y, Zhao Q, Liu J (2012) Improving the estimation of fractional-cycle biases for ambiguity resolution in precise point positioning. J Geod 86(8):579–589CrossRefGoogle Scholar
  16. Geng J, Zhao Q, Shi C, Liu J (2017) A review on the inter-frequency biases of GLONASS carrier-phase data. J Geod 91(3):329–340CrossRefGoogle Scholar
  17. Hatch R (1982) The synergism of GPS code and carrier measurements. In: Proceedings of the third international symposium on satellite Doppler positioning at Physical Sciences Laboratory of New Mexico State University, vol 2, 8–12 Feb, pp 1213–1231Google Scholar
  18. Laurichesse D, Mercier F, Berthias JP, Broca P, Cerri L (2009) Integer ambiguity resolution on undifferenced GPS phase measurements and its application to PPP and satellite precise orbit determination. Navigation 56(2):135–149CrossRefGoogle Scholar
  19. Leick A, Beser J, Li J, Mader G (1995) Processing GLONASS carrier phase observations-theory and first experience. In: Proceedings of ION-GPS-95, Institute of Navigation, Palm Springs, California, pp 1041–1047Google Scholar
  20. Liu Y, Ge MR, Shi C, Lou YD, Wickert J, Schuh H (2016) Improving integer ambiguity resolution for GLONASS precise orbit determination. J Geod 90(8):715–726CrossRefGoogle Scholar
  21. Reussner N, Wanninger L (2011) GLONASS inter-frequency biases and their effects on RTK and PPP carrier phase ambiguity resolution. In: Proceedings ION GNSS 2011, Institute of Navigation, Portland, OR, pp 712–716Google Scholar
  22. Roßbach U (2000) Positioning and navigation using the Russian satellite system GLONASS. Ph.D. Thesis, Universitaet der Bundeswehr MuenchenGoogle Scholar
  23. Schmid R, Steigenberger P, Gendt G, Ge M, Rothacher M (2007) Generation of a consistent absolute phase-center correction model for GPS receiver and satellite antennas. J Geod 81(12):781–798CrossRefGoogle Scholar
  24. Shi C, Yi W, Song W, Lou Y, Yao Y, Zhang R (2013) GLONASS pseudorange inter-channel biases and their effects on combined GPS/GLONASS precise point positioning. GPS Solut 17(4):439–451CrossRefGoogle Scholar
  25. Sleewaegen JM, Simsky A, De Wilde W, Boon F, Willems T (2012) Demystifying GLONASS inter-frequency carrier phase biases. Inside GNSS 7(3):57–61Google Scholar
  26. Teunissen PJG (1995) The least-squares ambiguity decorrelation adjustment: a method for fast GPS integer ambiguity estimation. J Geod 70(1):65–82CrossRefGoogle Scholar
  27. Wang J (2000) An approach to GLONASS ambiguity resolution. J Geod 74(5):421–430CrossRefGoogle Scholar
  28. Wang J, Rizos C, Stewart MP, Leick A (2001) GPS and GLONASS integration: modeling and ambiguity resolution issues. GPS Solut 5(1):55–64CrossRefGoogle Scholar
  29. Wanninger L (2012) Carrier-phase inter-frequency biases of GLONASS receivers. J Geod 86(2):139–148CrossRefGoogle Scholar
  30. Wu JT, Wu SC, Hajj GA, Bertiger WI, Lichten SM (1993) Effects of antenna orientation on GPS carrier phase. Manuscr Geodaet 18(2):91–98Google Scholar
  31. Xu P (2005) Sign-constrained robust least squares, subjective breakdown point and the effect of weights of observations on robustness. J Geod 79(1–3):146–159CrossRefGoogle Scholar
  32. Yamada H, Takasu T, Kubo N, Yasuda A (2010) Evaluation and calibration of receiver inter-channel biases for RTK-GPS/GLONASS. In: Proceedings of the 23rd international technical meeting of The Satellite Division of the Institute of Navigation, Portland, OR, pp 1580–1587Google Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2017

Authors and Affiliations

  • Qile Zhao
    • 1
  • Xiaotao Li
    • 1
  • Yang Liu
    • 1
  • Jianghui Geng
    • 1
    • 2
  • Jingnan Liu
    • 1
  1. 1.GNSS Research CenterWuhan UniversityWuhanChina
  2. 2.Collaborative Innovation Center of Geospatial TechnologyWuhanChina

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