Skip to main content

Application of SWACI products as ionospheric correction for single-point positioning: a comparative study

Abstract

In Global Navigation Satellite Systems (GNSS) using L-band frequencies, the ionosphere causes signal delays that correspond with link related range errors of up to 100 m. In a first order approximation the range error is proportional to the total electron content (TEC) of the ionosphere. Whereas this first order range error can be corrected in dual-frequency measurements by a linear combination of carrier phase- or code-ranges of both frequencies, single-frequency users need additional information to mitigate the ionospheric error. This information can be provided by TEC maps deduced from corresponding GNSS measurements or by ionospheric models. In this paper we discuss and compare different ionospheric correction methods for single-frequency users. The focus is on the comparison of the positioning quality using dual-frequency measurements, the Klobuchar model, the NeQuick model, the IGS TEC maps, the Neustrelitz TEC Model (NTCM-GL) and the reconstructed NTCM-GL TEC maps both provided via the ionosphere data service SWACI (http://swaciweb.dlr.de) in near real-time. For that purpose, data from different locations covering several days in 2011 and 2012 are investigated, including periods of quiet and disturbed ionospheric conditions. In applying the NTCM-GL based corrections instead of the Klobuchar model, positioning accuracy improvements up to several meters have been found for the European region in dependence on the ionospheric conditions. Further in mid- and low-latitudes the NTCM-GL model provides results comparable to NeQuick during the considered time periods. Moreover, in regions with a dense GNSS ground station network the reconstructed NTCM-GL TEC maps are partly at the same level as the final IGS TEC maps.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8

References

  1. Allain DJ, Mitchell CN (2008) Ionospheric delay corrections for single-frequency GPS receivers over Europe using tomographic mapping. GPS Solut. doi:10.1007/s10291-008-0107-y

    Google Scholar 

  2. Angrisano A, Gaglione S, Gioia C, Massaro M, Robustelli U (2013) Assessment of NeQuick ionospheric model for Galileo single-frequency users. Acta Geophys. doi:10.2478/s11600-013-0116-2

    Google Scholar 

  3. Covington AE (1969) Solar Radio Emission at 10.7 cm, 1947–1968. J Roy Astron Soc Can 63/3:125–132

    Google Scholar 

  4. DOD SPS, Department of Defense USA (2008) Global positioning system standard positioning service performance standard, 4th edn. http://www.gps.gov/technical/ps/2008-SPS-performance-standard. Accessed 6 Jan 2012

  5. EUROCONTROL Robert E (2012) Eurocontrol space weather activities. Space Weather Workshop, Boulder/CO

  6. Feltens J, Angling M, Jackson-Booth N, Jakowski N, Hoque M, Hernández-Pajares M, Aragón-Àngel A, Orús R, Zandbergen R (2011) Comparative testing of four ionospheric models driven with GPS measurements. Radio Sci 46:RS0D12. doi:10.1029/2010RS004584

    Article  Google Scholar 

  7. Galileo SIS ICD, European Commission (2010) European GNSS (Galileo) open service, signal in space interface control document. http://ec.europa.eu/enterprise/policies/satnav/galileo/open-service/. Accessed 30 Mar 2011

  8. GGOS, global geodetic observing system. http://ggosatm.hg.tuwien.ac.at/

  9. Hernández-Pajares M, Juan JM, Sanz J, Orús R, Garcia-Rigo A, Feltens J, Komjathy A (2009) The IGS VTEC maps: a reliable source of ionospheric information since 1998. J Geod 83:263–275. doi:10.1007/s00190-008-0266-1

    Article  Google Scholar 

  10. Hochegger G, Nava B, Radicella SM, Leitinger R (2000) A family of ionospheric models for different uses. Phys Chem Earth 25/4:307–310

    Google Scholar 

  11. Hoque MM, Jakwoski N (2013) Mitigation of ionospheric mapping function error. In: Proceedings of the ION GNSS+, Nashville/Tennessee/USA, 16–20 Sept

  12. IGS, International GNSS Service. http://www.igs.org

  13. IS-GPS-200F, Global Positioning System Directorate, Systems Engineering & Integration (2011) Interface specification, IS-GPS-200F. http://www.navcen.uscg.gov/pdf/IS-GPS-200F. Accessed 5 Sept 2012

  14. Jakowski N, Hoque MM, Mayer C (2011a) A new global TEC model for estimating transionospheric radio wave propagation errors. J Geod 85/12:965–974. doi:10.1007/s00190-011-0455-1

    Article  Google Scholar 

  15. Jakowski N, Mayer C, Hoque MM, Wilken V (2011b) Total electron content models and their use in ionosphere monitoring. Radio Sci 46:RS0D18

    Article  Google Scholar 

  16. Klobuchar J (1987) Ionospheric time-delay algorithm for single-frequency GPS users. IEEE T Aero Elec Sys 23:325–332

    Article  Google Scholar 

  17. Misra P, Enge P (2001) Global positioning system: signals, measurements, and performance. Ganga-Jamuna Press, Massachusetts

    Google Scholar 

  18. Nava B, Coisson P, Radicella SM (2008) A new version of the NeQuick ionosphere electron density model. J Atmos Sol-Terr Phy 70:1856–1862. doi:10.1016/j.jastp.2008.01.015

    Article  Google Scholar 

  19. Orús R, Hernández-Pajares M, Juan JM, Sanz J, García-Fernández A. (2002) Performance of different TEC models to provide GPS ionospheric corrections. J Atmos Sol-Terr Phy 64:2055–2062. doi:10.1007/s00190-008-0266-1. http://gage6.upc.es/gAGE_WEB/papers/2003/sdarticle. Accessed 20 Nov 2013

    Google Scholar 

  20. Radicella SM (2009) The NeQuick model genesis, uses and evolution. Ann Geophys-Italy 52(3):417–422

    Google Scholar 

  21. Rose ARJ, Allain DJ, Mitchell C (2009) Reduction in the ionospheric error for a single-frequency GPS timing solution using tomography. Ann Geophys Italy 52/5:469–486

    Google Scholar 

  22. Rostoker G (1972) Geomagnetic Indices. Rev Geophys Space Ge 10/4:935–950

    Article  Google Scholar 

  23. RTCA-DO229D (2006) Minimum operational performance standards for global positioning system/wide area augmentation system airborne equipment. 13 Dec

  24. Schaer S, Gurtner W, Feltens J. (1998) IONEX: The IONosphere Map EXchange Format Version 1. In: Proceedings of the IGS analysis centers workshop, ESOC, Darmstadt, 9–11 February. http://igscb.jpl.nasa.gov/igscb/data/format/ionex1. Accessed 10 Oct 2012

  25. Schueler T. (2001) On Ground-Based GPS Tropospheric Delay Estimation. Dissertation, University of the Federal Armed Forces Munich

  26. Seeber G (2003) Satellite Geodesy, 2nd edn. de Gruyter Press, Berlin/Germany

    Book  Google Scholar 

  27. SPIDR, Space Physics Interactive Data Resource. http://spidr.ngdc.noaa.gov/spidr/dataset.do

  28. Suard N, Azair JM, Gadat S, Debailleux D, Rifa E (2011) Assessment of an ionosphere storm occurence risk. European Navigation Conference, London 29 November–1 December

    Google Scholar 

  29. SWACI, Space Weather Application Center Ionosphere. http://swaciweb.dlr.de

  30. Tetewsky A, Ross J, Soltz A, Vaughn N, Anszperger J, O’Brien C, Graham D, Craig D, Lozow J. (2009) Making sense of GPS inter-signal corrections: satellite calibration parameters in legacy and modernized ionosphere correction algorithms. Inside GNSS 4(2): 37–48. http://www.insidegnss.com/auto/julyaug09-tetewsky-final. Accessed 5 Nov 2013

  31. WDC Kyoto, World Data Center for Geomagnetism Kyoto. http://wdc.kugi.kyoto-u.ac.jp

Download references

Acknowledgments

We would like to express our gratitude to the editors and reviewers for their remarks for the improvement of this paper. Additionally we thank IGS, SPIDR and WDC Kyoto for making available high quality GNSS and geo-related data. Further we would like to express our gratitude to the Aeronomy and Radiopropagation Laboratory of the Abdus Salam International Centre for Theoretical Physics Trieste/Italy providing NeQuick version 2.0.2 for scientific purposes. Finally, thanks to our colleagues of DLR’s Institute of Communications and Navigation maintaining provision of GNSS measurements via EVnet and to our colleagues of DLR’s Earth Observation Center supporting the SWACI service.

Author information

Affiliations

Authors

Corresponding author

Correspondence to David Minkwitz.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Minkwitz, D., Gerzen, T., Wilken, V. et al. Application of SWACI products as ionospheric correction for single-point positioning: a comparative study. J Geod 88, 463–478 (2014). https://doi.org/10.1007/s00190-014-0698-8

Download citation

Keywords

  • GNSS
  • Single-point positioning
  • Ionospheric delay
  • NTCM-GL TEC maps
  • NeQuick
  • IGS TEC maps
  • Klobuchar model
  • SWACI