Applied Geomatics

, Volume 11, Issue 1, pp 69–80 | Cite as

Code multipath analysis of Galileo FOC satellites by time-frequency representation

  • Umberto RobustelliEmail author
  • Giovanni Pugliano
Original Paper


Galileo is currently in full operational capability (FOC) phase with 18 FOC satellites. The purpose of this paper is to investigate the multipath performance of Galileo FOC signals E1, E5a, E5b, and E5. With the advent of FOC satellites, assessing the multipath behavior of Galileo FOC signals is becoming one of the greatest interests for the user’s community. In fact, the reduction of multipath has been one of the main criteria on which the Galileo signals have been designed. We analyzed data over three different days from six International GNSS Service (IGS) stations located at different latitudes, for all visible Galileo satellites. This is one of the first studies to present experimental results for the multipath of Galileo signals transmitted by FOC satellites since they started to operate in 2015. Code multipath was estimated using code-minus-carrier (CMC) and pseudorange multipath (MP) methods. The study involves a comparison with the GPS signals, showing results of multipath performance as function of satellite elevation. A time-frequency representation, based on the use of continuous wavelet transform (CWT), was performed to rigorously account for the presence of multipath. The expectations of FOC satellites to lead to a multipath reduction have been verified: the E5 signal shows the highest suppression of multipath as compared to the other Galileo and GPS signals and it is almost independent from the satellite elevation. An assigned FOC satellite showed a lower frequency multipath compared to a GPS satellite at the same azimuth and elevation, which is in line with a lower Galileo satellite elevation rate.


Galileo FOC satellites Time-frequency analysis Scalogram Continuous wavelet transform Multipath Code-minus-carrier Pseudorange multipath observable 


  1. Aram M, El-Rabbany A, Krishnan S, Anpalagan A (2007) Single frequency multipath mitigation based on wavelet analysis. Navigation 60(2):281–290CrossRefGoogle Scholar
  2. Bartone C, Zhang Y (2005) Real-time wavesmooth error mitigation for Global Navigation Satellite Systems. United States Patent Application Publication No. US 2005/0212696 A1Google Scholar
  3. Blanco-Delgado N, de Haag MU (2011) Multipath analysis using code-minus-carrier for dynamic testing of GNSS receivers. In: Proceedings of ICL-GNSS 2011, Tampere, Finland, pp. 25–30Google Scholar
  4. Borio D, Lo Presti P (2008) Data and pilot combining for composite GNSS signal acquisition. International journal of navigation and observation, volume 2008, 12 pagesGoogle Scholar
  5. Braasch MS (1996) Multipath Effects. Global positioning system: theory and applications, vol I. American Institute of Aeronautics and Astronautics, Washington, DC, pp 547–568Google Scholar
  6. Changsheng C, Chang H, Rock S, Lin P, Xianqiang C, Jianjun Z (2016) A comparative analysis of measurement noise and multipath for four constellations: GPS, BeiDou, GLONASS and Galileo. Surv Rev 48(349):287–295CrossRefGoogle Scholar
  7. Circiu MS, Meurer M, Felux M, Gerbeth D, Thölert S, Vergara M, Enneking C, Sgammini M, Pullen S, Antreich F (2017) Evaluation of GPS L5 and Galileo E1 and E5a performance for future multifrequency and multiconstellation GBAS. Navigation 64(1):149–163CrossRefGoogle Scholar
  8. de Bakker P, van der Marel H, Tiberius C (2009) Geometry-free undifferenced, single and double differenced analysis of single frequency GPS, EGNOS and GIOVE-A/B measurements. GPS Solutions 13(4):305–314CrossRefGoogle Scholar
  9. de Bakker P, Tiberius C, van der Marel H, van Bree R (2012) Short and zero baseline analysis of GPS L1 C/A, L5Q, GIOVE E1B, and E5aQ signals. GPS Solutions 16(1):53–64CrossRefGoogle Scholar
  10. Defraigne P, Bruyninx C (2007) On the link between GPS pseudorange noise and day-boundary discontinuities in geodetic time transfer solutions. GPS Solutions 11(1):239–249CrossRefGoogle Scholar
  11. Diessongo H, Schuler T, Junker S (2014) Precise position determination using a Galileo E5 single-frequency receiver. GPS Solutions 18(1):73–83CrossRefGoogle Scholar
  12. Dow JM, Neilan RE, Rizos C (2009) The International GNSS service in a changing landscape of global navigation satellite systems. J Geod 83(3):191–198CrossRefGoogle Scholar
  13. El-Rabbany A (2002) Introduction to GPS: the global positioning system. Artech House, Boston LondonGoogle Scholar
  14. Estey LH, Meertens CM (1999) TEQC: the multi-purpose toolkit for GPS/GLONASS data. GPS Solutions 3(1):42–49CrossRefGoogle Scholar
  15. Hakansson M, Jensen A, Horemuz M, Hedling G (2017) Review of code and phase biases in multi-GNSS positioning. GPS Solutions 21(3):849–860CrossRefGoogle Scholar
  16. Hofmann-Wellenhof B, Lichtenegger H, Collins J (2001) Global positioning system: theory and practice, 5th edn. Springer Verlag Wien, New YorkCrossRefGoogle Scholar
  17. Julien O, Lachapelle G, Cannon ME (2004) A new multipath and noise mitigation technique using data/data-less navigation signals. Proc. ION GNSS 2004, Institute of Navigation, Long Beach, California, USA, September 21-24, 8–19Google Scholar
  18. Leick A (2004) GPS satellite surveying, 3rd edn. John Wiley & Sons, New YorkGoogle Scholar
  19. Mannucci AJ, Iijima BA, Wilson BD, Peck S, Ahmadi R (1997) Wide area Ionospheric delay corrections under ionospheric storm conditions. Proc. ION NTM 1997, Institute of Navigation, Santa Monica, California, USA, January 14–16, 871–882Google Scholar
  20. Navarro-Reyes D, Castro R, Bosch P (2015) Galileo first FOC launch: recovery mission design 25th International Symposium on Space Flight Dynamics ISSFD October 19–23, Munich, GermanyGoogle Scholar
  21. OS SIS ICD (2015) European GNSS (Galileo) open service, signal in space, interface control document. European Union and European Space Agency (ESA), tech rep, Issue 1.2Google Scholar
  22. Paziewski J, Sieradzki R, Wielgosz P (2018) On the applicability of Galileo FOC satellites with incorrect highly eccentric orbits: an evaluation of instantaneous medium-range positioning. Remote Sens 10:208CrossRefGoogle Scholar
  23. Petovello M, Groves P (2013) Multipath vs. NLOS signals. Inside GNSS November–December 2013: 40–44Google Scholar
  24. Pugliano G, Robustelli U, Rossi F, Santamaria R (2016) A new method for specular and diffuse pseudorange multipath error extraction using wavelet analysis. GPS Solutions 20(3):499–508CrossRefGoogle Scholar
  25. Satirapod C, Rizos C (2005) Multipath mitigation by wavelet analysis for GPS base station applications. Surv Rev 38(295):2–10CrossRefGoogle Scholar
  26. Seepersad G, Bisnath S (2014) Reduction of PPP convergence period through pseudorange multipath and noise mitigation. GPS Solutions 19(3):369–379CrossRefGoogle Scholar
  27. Simsky A, Sleewaegen J, Hollreiser M, Crisci M (2006) Performance assessment of Galileo ranging signals transmitted by GSTB-V2 satellites. Proc. ION GNSS 2006, Institute of Navigation, Fort Worth, Texas, USA, September 26-29, 1547–1559Google Scholar
  28. Simsky A, Mertens D, Sleewaegen J, Hollreiser M, Crisci M (2008) Experimental results for the multipath performance of Galileo signals transmitted by GIOVE-A satellite. International Journal of Navigation and Observation, vol 2008Google Scholar
  29. Smith SW (1999) The scientist and engineer’s guide to digital signal processing. California Technical Publishing, San DiegoGoogle Scholar
  30. Soloviev A, Kuusniemi H, Bisnath S (2007) Backing up GNSS with laser radar & INS, RAIM in the city, antenna phase wind-up. Inside GNSS July/August pp 32–35Google Scholar
  31. Sosnica K, Prange L, Kazmierski K, Bury G, Drozdzewski M, Zajedel R, Hadas T (2018) Validation of Galileo orbits using SLR with a focus on satellites launched into incorrect orbital planes. J Geod 92:131–148CrossRefGoogle Scholar
  32. Souza EM, Monico JFG (2004) Wavelet shrinkage: high frequency multipath reduction from GPS relative positioning. GPS Solutions 8(3):152–159CrossRefGoogle Scholar
  33. Tawk Y, Botteron C, Jovanovic A, Farine P (2011) Analysis of Galileo E5 and E5ab code tracking. GPS Solutions 16(2):243–258CrossRefGoogle Scholar
  34. Yates R, Lyon R (2008) DC blocker algorithms. IEEE Signal Process Mag 25(2):132–134CrossRefGoogle Scholar
  35. Zaminpardaz S, Teunissen PJG (2017) Analysis of Galileo IOV + FOC signals and E5 RTK performance. GPS Solutions 21(4):1855–1870CrossRefGoogle Scholar
  36. Zhang J, Lohan E (2011) Galileo E1 and E5a link-level performances in single and multipath channels. Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering (LNICST) 71:378–390CrossRefGoogle Scholar

Copyright information

© Società Italiana di Fotogrammetria e Topografia (SIFET) 2018

Authors and Affiliations

  1. 1.Department of EngineeringParthenope University of NaplesNaplesItaly

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