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Extension of the undifferenced and uncombined CDMA PPP-RTK for not-common-frequency GNSS observations

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Abstract

Integer ambiguity resolution enabled precise point positioning, PPP-RTK, which is becoming one of the most popular global navigation satellite system (GNSS) positioning modes. Owing to the presence of rank deficiencies in the system of GNSS observation equations, one needs to choose some of the GNSS parameters as S-basis and let the remaining parameters absorb them. Doing so forms a full-rank PPP-RTK model whose combined parameters are estimable. To simplify the model construction, previous contributions assume that observations are tracked on common-frequency (CF) bands for all the involved receiver-satellite pairs. Such a model is referred to as CF PPP-RTK. However, the coexistence of legacy and modernized GNSS signal systems, together with the presence of outdated and updated receiver firmware, leads to not-common-frequency (NCF) cases where some of the involved receivers fail to track observations on certain frequencies. For such cases, the CF PPP-RTK model discards part of the observations so as to maintain the CF assumption. In this contribution, we refrain from making the CF assumption and extend the GNSS undifferenced and uncombined formulation to NCF cases. Such a NCF PPP-RTK model ensures that all observations contribute to the parameter estimation process, avoiding losing any information content in the data. As a result, our proposed NCF PPP-RTK avoids any potential reduction in both the availability and the precision of the corrections. To evaluate the positioning performance of the proposed model, we conducted three experiments with continuously operating reference station data in Hong Kong, Australia, and Europe. The superiority of the NCF PPP-RTK model over its conventional CF PPP-RTK version is illustrated in terms of both the time-to-first-fix and root mean square positioning errors.

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Data availability

The GNSS data used in this contribution are freely accessible via ftp://ftp.geodetic.gov.hk/, https://gnss.ga.gov.au/, https://epncb.oma.be/.

References

  • Bruyninx C, Legrand J, Fabian A, Pottiaux E (2019) GNSS metadata and data validation in the EUREF permanent network. GPS Solut 23:106

    Article  Google Scholar 

  • Collins P (2008) Isolating and estimating undifferenced GPS integer ambiguities. Proc. ION GNSS 2008, Institute of Navigation, San Diego, California, USA. January 28–30, 720–732.

  • Euler HJ, Goad CC (1991) On optimal filtering of GPS dual frequency observations without using orbit information. Bull Geod 65:130–143

    Article  Google Scholar 

  • 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 Geodesy 82(7):389–399

    Article  Google Scholar 

  • Geng J, Wen Q, Zhang Q, Li G, Zhang K (2022) GNSS observablespecifc phase biases for all-frequency PPP ambiguity resolution. J Geod 96:11

    Article  Google Scholar 

  • Khodabandeh A, Teunissen PJG (2019) Integer estimability in GNSS networks. J Geodesy 93(9):1805–1819

    Article  Google Scholar 

  • Li J, Yang Y, He H, Guo H (2020) Benefts of BDS-3 B1C/B1I/B2a triple-frequency signals on precise positioning and ambiguity resolution. GPS Solut 24:100

    Article  Google Scholar 

  • Li X, Huang J, Li X, Shen Z, Han J, Li L (2022) Wang B (2022) Review of PPP–RTK: achievements, challenges, and opportunities. Satell Navig 3:28

    Article  Google Scholar 

  • Montenbruck O, Hauschild A, Steigenberger P, Hugentobler U, Teunissen PJG, Nakamura S (2013) Initial assessment of the COMPASS/BeiDou-2 regional navigation satellite system. GPS Solut 17(2):211–222

    Article  Google Scholar 

  • Montenbruck O et al (2017) The multi-GNSS experiment (MGEX) of the international GNSS service (IGS)—achievements, prospects and challenges. Adv Space Res 59:1671–1697

    Article  Google Scholar 

  • Odijk D (2000) Weighting ionospheric corrections to improve fast GPS positioning over medium distances. In: Proceedings of the ION GPS-2000, Salt Lake City UT, pp 1113–1123

  • Psychas D, Verhagen S, Liu X, Memarzadeh Y, Visser H (2018) Assessment of ionospheric corrections for PPP-RTK using regional ionosphere modeling. Meas Sci Technol 30:014001

    Article  Google Scholar 

  • Teunissen PJG (1990) Quality control in integrated navigation systems. IEEE Aerosp Electron Syst Mag 5(7):35–41

    Article  Google Scholar 

  • Teunissen PJG (1999) An optimality property of the integer leastsquares estimator. J Geod 73:587–593

    Article  Google Scholar 

  • Teunissen P, Khodabandeh A (2015) Review and principles of PPPRTK methods. J Geodesy 89(3):217–240

    Article  Google Scholar 

  • Teunissen P, Montenbruck O (2017) Springer handbook of global navigation satellite systems. Springer International Publishing, Switzerland

    Book  Google Scholar 

  • Teunissen PJG, Odijk D, Zhang B (2010) PPP-RTK: results of CORS network-based PPP with integer ambiguity resolution. J Aeronaut Astronaut Aviation Ser A 42(4):223–230

    Google Scholar 

  • Tran M (2004) Performance evaluations of the new GPS L5 and L2 civil (L2c) signals. Navigation 51(3):199–212

    Article  Google Scholar 

  • Wang K, Sun B, Qin W, Mi X, El-Mowafy A, Yang X (2023) A method of real-time long-baseline time transfer based on the PPP-RTK. GPS Solut 71(3):1363–1376

    Google Scholar 

  • Wübbena G, Schmitz M, Andreas B (2005) PPP-RTK: precise point positioning using state-space representation in RTK networks. In: Proceedings of ION GNSS 2005, Institute of Navigation, Long Beach, California, USA. 13–16 September, pp 2584–2594

  • Yang Y, Liu L, Li J, Yang Y, Zhang T, Mao Y, Sun B, Ren X (2021) Featured services and performance of BDS-3. Sci Bull 66(20):2135–2143

    Article  Google Scholar 

  • Zha J, Zhang B, Liu T, Hou P (2021) Ionosphere-weighted undifferenced and uncombined PPP–RTK: theoretical models and experimental results. GPS Solut 25(4):1–12

    Article  Google Scholar 

  • Zhang B, Teunissen PJG, Odijk D (2011) A novel undiferenced PPP-RTK concept. J Navig 64(S1):S180–S191

    Article  Google Scholar 

  • Zhang B, Hou P, Odolinski R (2022) PPP-RTK: from common-view to all-in-view GNSS networks. J Geod 96:102

    Article  Google Scholar 

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Acknowledgements

The authors would like to thank Dr. Pengyu Hou for his insightful discussions on this research.

Funding

This work was funded by the National Natural Science Foundation of China (Grant No. 42022025). The corresponding author is supported by the CAS Pioneer Hundred Talents Program.

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CK processed the data. BZ proposed the method and designed the research. CK and AK analyzed the results and edited the text. CK and BZ wrote the manuscript.

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Correspondence to Baocheng Zhang.

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Ke, C., Zhang, B. & Khodabandeh, A. Extension of the undifferenced and uncombined CDMA PPP-RTK for not-common-frequency GNSS observations. GPS Solut 28, 102 (2024). https://doi.org/10.1007/s10291-024-01644-4

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