Skip to main content
SpringerLink
Log in

Estimation of GPS LNAV based on IGS products for real-time PPP

  • Original Article
  • Published:
GPS Solutions Aims and scope Submit manuscript

Abstract

Precise satellite orbit and clock corrections are essential to precise point positioning (PPP). The standard GPS legacy navigation (LNAV) message disseminated by the satellite is one of the most widely used sources for deriving orbit and clock corrections in real-time using efficient analytical user algorithms. However, the quality of the satellite orbit and clock corrections computed with the standard LNAV is not adequate for real-time PPP mainly due to the low update rate. In this study, we proposed an improved LNAV which is estimated based on the IGS ultra-rapid (IGU) orbit and real-time service (RTS) clock products. Two advantages characterize this improved LNAV message. The first one is that scalable update rates can be used for disseminating satellite orbit and clock corrections. Users can decide to receive and decode the improved LNAV message at the desired update rate considering the availability of correction streams, communication bandwidth, and targeted accuracy. With sufficiently high update rates, the improved LNAV can be applied for high-precision applications such as real-time PPP. The second advantage is that the legacy user algorithms can be maintained for computing real-time satellite orbit and clock corrections. Since the improved LNAV has the same parameter representation as the standard LNAV, no changes are required at the user algorithms. To validate the proposed method, the quality of real-time orbit and clock corrections computed with the improved LNAV, IGU products, Centro Nacional de Estudios Espaciales (CNES) real-time products, and the standard LNAV is compared, while the IGS final products are used as the reference. The numerical results indicate that the improved LNAV can achieve comparable orbit accuracy as CNES real-time products, while the clock accuracy highly depends on the update rate. A globally distributed network of 40 IGS stations is used to assess the kinematic PPP performance. Using the improved LNAV with update intervals of 5 min, an average positioning accuracy of 0.122, 0.100, and 0.242 m at 95% confidence level can be obtained in the east, north, and up directions, respectively. Even when the update intervals extend to 2 h, the positioning accuracy is still about 1.2 times better than that of using IGU products. The proposed method provides a scalable and flexible way to improve the standard LNAV for real-time PPP users.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11

Similar content being viewed by others

References

  • Allan DW (1987) Time and frequency (time-domain) characterization, estimation, and prediction of precision clocks and oscillators. IEEE Trans Ultrason Ferroelectr Freq Control 34(6):647–654

    Article  Google Scholar 

  • Bisnath S, Gao Y (2008) Current state of precise point positioning and future prospects and limitations. IAG Symp 133:615–623

    Google Scholar 

  • Böhm J, Niell A, Tregoning P, Schuh H (2006) Global mapping function (GMF): a new empirical mapping function based on numerical weather model data. Geophys Res Lett 33(7):L07304

    Google Scholar 

  • Caissy M, Weber G, Agrotis L, Wübbena G, Hernandez-Pajares M (2011) The IGS real-time pilot project—the development of real-time IGS correction products for precise point positioning. In: EGU General Assembly, Geophysics Research Abstracts 13, EGU2011-7472

  • Dierendonck AJV, Russell SS, Kopitzke ER, Birnbaum M (1978) The GPS navigation message. Navigation 25(2):147–165

    Article  Google Scholar 

  • Dow JM, Neilan RE, Rizos C (2009) The International GNSS Service in a changing landscape of global navigation satellite systems. J Geod 83(3–4):191–198

    Article  Google Scholar 

  • Du L, Zhang Z, Zhang J, Liu L, Guo R, He F (2015) An 18-element GEO broadcast ephemeris based on non-singular elements. GPS Solut 19(1):49–59

    Article  Google Scholar 

  • El-Mowafy A, Deo M, Kubo N (2017) Maintaining real-time precise point positioning during outages of orbit and clock corrections. GPS Solut 21(3):937–947

    Article  Google Scholar 

  • Fu X, Wu M (2012) Optimal design of broadcast ephemeris parameters for a navigation satellite system. GPS Solut 16(4):439–448

    Article  Google Scholar 

  • Gao Y, Zhang W, Li Y (2016) A new method for real-time PPP correction updates. In: International symposium on earth and environmental sciences for future generations, IAG Symp 147, p 223

  • Hadas T, Bosy J (2015) IGS RTS precise orbits and clocks verification and quality degradation over time. GPS Solut 19(1):93–105

    Article  Google Scholar 

  • Herring TA, King RW, McClusky SC (2010) Introduction to GAMIT/GLOBK. Massachusetts Institute of Technology, Cambridge

    Google Scholar 

  • Heßelbarth A, Wanninger L (2013) SBAS orbit and satellite clock corrections for precise point positioning. GPS Solut 17(4):465–473

    Article  Google Scholar 

  • Kazmierski K, Sośnica K, Hadas T (2018) Quality assessment of multi-GNSS orbits and clocks for real-time precise point positioning. GPS Solut 22(1):11

    Article  Google Scholar 

  • Kouba J (2009) A guide to using International GNSS Service (IGS) products

  • Li L, Jia C, Zhao L, Cheng J, Liu J, Ding J (2016) Real-time single frequency precise point positioning using SBAS corrections. Sensors 16(8):1261

    Article  Google Scholar 

  • Malys S, Jensen PA (1990) Geodetic point positioning with GPS carrier beat phase data from the CASA UNO Experiment. Geophys Res Lett 17(5):651–654

    Article  Google Scholar 

  • Montenbruck O, Steigenberger P, Hauschild A (2015) Broadcast versus precise ephemerides: a multi-GNSS perspective. GPS Solut 19(2):321–333

    Article  Google Scholar 

  • Nie Z, Gao Y, Wang Z, Ji S, Yang H (2018) An approach to GPS clock prediction for real-time PPP during outages of RTS stream. GPS Solut 22(1):14

    Article  Google Scholar 

  • Petit G, Luzum B (2010) IERS conventions (2010), IERS Technical Note 36. Verlag des Bundesamts für Kartographie und Geodäsie, Frankfurt am Main

    Google Scholar 

  • RTCM Special Committee (2016) RTCM Standard 10403.3 differential GNSS (Global Navigation Satellite Systems) Services-Version 3. RTCM Special Committee No. 104, Arlington

    Google Scholar 

  • 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):781–798

    Article  Google Scholar 

  • Springer TA, Hugentobler U (2001) IGS ultra rapid products for (near-) real-time applications. Phys Chem Earth 26(6–8):623–628

    Article  Google Scholar 

  • Takasu T (2013) RTKLIB ver. 2.4.2 Manual. 2013 edn. Tokyo University of Marine Science and Technology, Tokyo

    Google Scholar 

  • U.S. Air Force (2015) Global Positioning Systems Directorate Systems Engineering and Integration Interface Specification IS-GPS-200

  • Weber G, Dettmering D, Gebhard H (2005) Networked Transport of RTCM via Internet Protocol (NTRIP). IAG Symp 128:60–64

    Google Scholar 

  • Wu JT, Wu SC, Hajj GA, Bertiger W, Lichten SM (1992) Effects of antenna orientation on GPS carrier phase. Adv Astronaut Sci 76(2):1647–1660

    Google Scholar 

  • Xiao G, Sui L, Heck B, Zeng T, Tian Y (2018) Estimating satellite phase fractional cycle biases based on Kalman filter. GPS Solut 22(3):82

    Article  Google Scholar 

  • Yang H, Xu C, Gao Y (2017) Analysis of GPS satellite clock prediction performance with different update intervals and application to real-time PPP. Surv Rev 23:1–10

    Google Scholar 

  • Zhang X, Li X, Guo F (2011) Satellite clock estimation at 1 Hz for realtime kinematic PPP applications. GPS Solut 15(4):315–324

    Article  Google Scholar 

  • Zhang L, Yang H, Gao Y, Yao Y, Xu C (2018) Evaluation and analysis of real-time precise orbits and clocks products from different IGS analysis centers. Adv Space Res 61(12):2942–2954

    Article  Google Scholar 

  • Zumberge JF, Heflin MB, Jefferson DC, Watkins MM, Webb FH (1997) Precise point positioning for the efficient and robust analysis of GPS data from large networks. J Geophys Res 102(B3):5005–5017

    Article  Google Scholar 

Download references

Acknowledgements

The IGS and CNES are acknowledged for providing the GNSS products. The study is partly supported by National Natural Science Foundation of China (Nos. 41774038, 41804034). The first author is funded by the China Scholarship Council and the Natural Sciences and Engineering Research Council of Canada (NSERC) which are also acknowledged. The authors also thank the editor and the anonymous reviewers for their helpful suggestions.

Author information

Authors and Affiliations

  1. Department of Geomatics Engineering, University of Calgary, Calgary, Canada

    Peiyuan Zhou, Hongzhou Yang & Yang Gao

  2. Geodetic Institute, Karlsruhe Institute of Technology, Karlsruhe, Germany

    Guorui Xiao

  3. Zhengzhou Institute of Surveying and Mapping, Zhengzhou, China

    Guorui Xiao & Lan Du

Authors
  1. Peiyuan Zhou
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Hongzhou Yang
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Guorui Xiao
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Lan Du
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Yang Gao
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Lan Du.

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Zhou, P., Yang, H., Xiao, G. et al. Estimation of GPS LNAV based on IGS products for real-time PPP. GPS Solut 23, 27 (2019). https://doi.org/10.1007/s10291-018-0820-0

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s10291-018-0820-0

Keywords

Search

Navigation