GPS Solutions

, Volume 16, Issue 3, pp 303–313 | Cite as

Apparent clock variations of the Block IIF-1 (SVN62) GPS satellite

  • Oliver MontenbruckEmail author
  • Urs Hugentobler
  • Rolf Dach
  • Peter Steigenberger
  • André Hauschild
Original Article


The Block IIF satellites feature a new generation of high-quality rubidium clocks for time and frequency keeping and are the first GPS satellites transmitting operational navigation signals on three distinct frequencies. We investigate apparent clock offset variations for the Block IIF-1 (SVN62) spacecraft that have been identified in L1/L2 clock solutions as well as the L1/L5-minus-L1/L2 clock difference. With peak-to-peak amplitudes of 10–40 cm, these variations are of relevance for future precision point positioning applications and ionospheric analyses. A proper characterization and understanding is required to fully benefit from the quality of the new signals and clocks. The analysis covers a period of 8 months following the routine payload activation and is based on GPS orbit and clock products generated by the CODE analysis center of the International GNSS Service (IGS) as well as triple-frequency observations collected with the CONGO network. Based on a harmonic analysis, empirical models are presented that describe the sub-daily variation of the clock offset and the inter-frequency clock difference. These contribute to a better clock predictability at timescales of several hours and enable a consistent use of L1/L2 clock products in L1/L5-based positioning.


GPS L5 Block IIF SVN62 Rubidium clock Allan variance CONGO 



The authors acknowledge the vital role of the International GNSS Service to this analysis. Orbit and clock solutions for SVN62 have been contributed by the Center for Orbit Determination in Europe (CODE) based on observations of the IGS network. CODE is a joint venture between the Astronomical Institute of the University of Bern (AIUB, Bern, Switzerland), the Federal Office of Topography (swisstopo, Wabern, Switzerland), the Federal Agency for Cartography and Geodesy (BKG, Frankfurt, Germany), and the Institut für Astronomische und Physikalische Geodäsie of the Technische Universität München (IAPG/TUM, Munich, Germany). It acts as a global analysis center of the IGS since June 1992. Triple-frequency observations have been provided by the CONGO multi-GNSS network. The contributions of all network partners (Deutsches Zentrum für Luft- und Raumfahrt, Bundesamt für Kartographie und Geodäsie, Technische Universität München, Deutsches GeoForschungsZentrum, Centre National d’Etudes Spatiales, Geoscience Australia) and local station hosts are gratefully acknowledged.


  1. Alonso M, Finn EJ (1967) Fundamental university physics, vol II, fields and waves. Addison-Wesley, ReadingGoogle Scholar
  2. Bock H, Dach R, Jäggi A, Beutler B (2009) High-rate GPS clock corrections from CODE: support of 1 Hz applications. J Geodesy 83(11):1083–1094. doi: 10.1007/s00190-009-0326-1 CrossRefGoogle Scholar
  3. Braschak M, Brown H Jr., Carberry J, Grant T, Hatten G, Patocka R, Watts E (2010) GPS IIF satellite overview, ION-GNSS-2010, 21–24 Sept 2010, Portland, ORGoogle Scholar
  4. Dach R, Brockmann E, Schaer S, Beutler G, Meindl M, Prange L, Bock H, Jäggi A, Ostini L (2009) GNSS processing at CODE: status report. J Geodesy 83(3–4):353–365. doi: 10.1007/s00190-008-0281-2 CrossRefGoogle Scholar
  5. Dilssner F (2010) GPS IIF-1 satellite—antenna phase center and attitude modeling. InsideGNSS, Sept 2010, pp 59–64Google Scholar
  6. Dorsey AJ, Marquis WA, Fyfe PM, Kaplan ED, Wiederholt LF (2006) GPS system segments. In: Kaplan ED, Hegarty CJ (eds) Understanding GPS—principles and applications, 2nd edn. Artech House, Norwood, pp 67–112Google Scholar
  7. Dow JM, Neilan RE, Rizos C (2009) The international GNSS service in a changing landscape of global navigation satellite systems. J Geodesy 83(3–4):191–198. doi: 10.1007/s00190-008-0300-3 CrossRefGoogle Scholar
  8. Dupuis RT, Lynch TJ, Vaccaro JR, Watts ET (2010) Rubidium frequency standard for the GPS IIF program and modifications for the RAFSMOD program. ION-GNSS-2010, 21–24 Sept 2010, Portland, ORGoogle Scholar
  9. Griffiths J, Ray JR (2009) On the precision and accuracy of IGS orbits. J Geodesy 83(3–4):277–287. doi: 10.1007/s00190-008-0237-6 CrossRefGoogle Scholar
  10. Kouba J (2004) Improved relativistic clock correction due to earth oblateness. GPS Solut 8(3):170–180. doi: 10.1007/s10291-004-0102-x CrossRefGoogle Scholar
  11. Kouba J (2009) A simplified yaw-attitude model for eclipsing GPS satellites. GPS Solut 13:1–12. doi: 10.1007/s10291-008-0092-1 CrossRefGoogle Scholar
  12. Montenbruck O, Hauschild A, Steigenberger P, Langley RB (2010a) Three’s the challenge: a close look at GPS SVN62 triple-frequency signal combinations finds carrier-phase variations on the new L5. GPS World 21(8):8–19Google Scholar
  13. Montenbruck O, Hauschild A, Hessels U (2010b) Characterization of GPS/GIOVE sensor stations in the CONGO network. GPS Solut 15(3):193–205. doi: 10.1007/s10291-010-0182-8 CrossRefGoogle Scholar
  14. Riley WR (2008) Handbook of frequency stability analysis, NIST special publication 1065. National Institute of Standards and Technology, Boulder, COGoogle Scholar
  15. Senior K (2010) SVN62 clock analysis using IGS data, IGSMAIL-6218, 6 Aug 2010,
  16. Senior K, Ray JR, Beard RL (2008) Characterization of periodic variations in the GPS satellite clocks. GPS Solut 12(3):211–225. doi: 10.1007/s10291-008-0089-9 CrossRefGoogle Scholar
  17. Spits J, Warnant R (2008) Total electron content monitoring using triple frequency GNSS data: a three-step approach. J Atmospheric Solar-Terr Phys 70(15):1885–1893. doi: 10.1016/j.jastp.2008.03.007 CrossRefGoogle Scholar
  18. Teunissen PJG, Joosten P, Tiberius C (2002) A comparison of TCAR, CIR and LAMBDA GNSS ambiguity resolution. ION-GPS-2002, Portland, OR, pp 2799–2808Google Scholar
  19. Tsai Y-H, Chang F-R, Yang W-C, Ma C-L (2004) Using multi-frequency for GPS positioning and receiver autonomous integrity monitoring. In: Proceedings of the 2004 IEEE international conference on control applications, Taipei, Taiwan, 2–4 Sept 2004Google Scholar
  20. Vannicola F, Beard R, White J, Senior K, Kubik A, Wilson D (2010) GPS Block IIF rubidium frequency standard life test. ION-GNSS-2010, 21–24 Sept 2010, Portland, ORGoogle Scholar
  21. Wu A (1996) Performance evaluation of the GPS Block IIR time keeping system. In: Breakiron L (ed) Proceedings of the 28th annual precise time and time interval applications and planning meeting. US Naval Observatory, Reston, pp 441–453Google Scholar
  22. Wu JT, Wu SC, Hajj GA, Bertiger WI, Lichten SM (1993) Effects of antenna orientation on GPS carrier phase. Manuscripta Geodaetica 18:91–98Google Scholar

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Oliver Montenbruck
    • 1
    Email author
  • Urs Hugentobler
    • 2
  • Rolf Dach
    • 3
  • Peter Steigenberger
    • 2
  • André Hauschild
    • 1
  1. 1.German Space Operations Center, Deutsches Zentrum für Luft- und RaumfahrtWeßlingGermany
  2. 2.Institut für Astronomische und Physikalische Geodäsie, Technische Universität MünchenMunichGermany
  3. 3.Astronomical Institute, University of BernBernSwitzerland

Personalised recommendations