Journal of Geodesy

, Volume 81, Issue 2, pp 111–120 | Cite as

Calibration errors on experimental slant total electron content (TEC) determined with GPS

  • L. Ciraolo
  • F. AzpilicuetaEmail author
  • C. Brunini
  • A. Meza
  • S. M. Radicella
Original Article


The Global Positioning System (GPS) has become a powerful tool for ionospheric studies. In addition, ionospheric corrections are necessary for the augmentation systems required for Global Navigation Satellite Systems (GNSS) use. Dual-frequency carrier-phase and code-delay GPS observations are combined to obtain ionospheric observables related to the slant total electron content (sTEC) along the satellite-receiver line-of-sight (LoS). This observable is affected by inter-frequency biases [IFB; often called differential code biases (DCB)] due to the transmitting and the receiving hardware. These biases must be estimated and eliminated from the data in order to calibrate the experimental sTEC obtained from GPS observations. Based on the analysis of single differences of the ionospheric observations obtained from pairs of co-located dual-frequency GPS receivers, this research addresses two major issues: (1) assessing the errors translated from the code-delay to the carrier-phase ionospheric observable by the so-called levelling process, applied to reduce carrier-phase ambiguities from the data; and (2) assessing the short-term stability of receiver IFB. The conclusions achieved are: (1) the levelled carrier-phase ionospheric observable is affected by a systematic error, produced by code-delay multi-path through the levelling procedure; and (2) receiver IFB may experience significant changes during 1 day. The magnitude of both effects depends on the receiver/antenna configuration. Levelling errors found in this research vary from 1.4 total electron content units (TECU) to 5.3 TECU. In addition, intra-day vaiations of code-delay receiver IFB ranging from 1.4 to 8.8 TECU were detected.


Total electron content (TEC) GPS, Inter-frequency bias Differential code bias (DCB) Levelling carrier to code TEC 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Azpilicueta F, Brunini C, Radicella SM (2005) Global ionospheric maps from GPS observations using modip latitude. Adv Space Res JARS 7882:8. DOI 10.1016/j.asr.2005.07.069 (in press)Google Scholar
  2. Bassiri S, Hajj A (1992) Higher order ionospheric effects on the Global Positioning System observables and means of modelling them. manuscripta geodaetica 18:280–290Google Scholar
  3. Beutler G, Rotacher M, Schaer, Springer TA, Kouba J, Neilan RE (1999) The International GPS Service (IGS): an interdisciplinary service in support of Earth sciences. Adv Space Res 23(4):631–653. DOI 10.1016/S0273-1177(99)00160-XCrossRefGoogle Scholar
  4. Bishop G, Walsh D, Daly P, Mazzella A, Holland E (1994) Analysis of the temporal stability of GPS and GLONASS group delay correction terms seen in various sets of ionospheric delay data. In: Proceedings of the ION GPS-94, Salt Lake City, pp 1653–1661Google Scholar
  5. Blewitt G (1990) An automatic editing algorithm for GPS data. Geophys Res Lett 17(3):199–202Google Scholar
  6. Braasch M (1996) Multi-path effects. In: Parkinson BW Spilker JJ (eds) Global Positioning System: theory and applications, vol 1. Progress in astronautics and aeronautics, American Institute of Aeronautics and Astronautics, pp 547–568Google Scholar
  7. Brunini C (1998) Global Ionospheric model from GPS measurements. PhD thesis, Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, La PlataGoogle Scholar
  8. Brunini C, van Zele MA, Meza A, Gende M (2003) Quiet and perturbed ionospheric representation according to the electron content from GPS signals. J Geophys Res 108:SIA4-1. CiteID 1056. DOI A2 10.1029/2002JA009346Google Scholar
  9. Brunini C, Meza A, Azpilicueta F, van Zele A, Gende M, Diaz A (2004) A new ionosphere monitoring technology based on GPS. Astrophys Space Sci 290:415–429. DOI 10.1023/B:ASTR.0000032540.35594.64CrossRefGoogle Scholar
  10. Brunini C, Meza A, Bosch W (2005) Temporal and spatial variability of the bias between TOPEX- and GPS-derived total electron content. J Geod 79. DOI 10.1007/s00190-005-0448-zGoogle Scholar
  11. Brunner FK, Gu M (1991) An improved model for the dual frequency ionospheric correction of GPS observations. manuscripta geodaetica 16:205–214Google Scholar
  12. Byun SH, Hajj GA, Young LE (2002) Development and application of GPS signal multi-path simulator. Radio Sci 37(6):1098. DOI 10.1029/2001RS002549CrossRefGoogle Scholar
  13. Davies K, Hartmann GK (1997) Studying the ionosphere with the Global Positioning System. Radio Sci 32(4):1695–1703CrossRefGoogle Scholar
  14. Feltens J (1998) Chapman Profile Approach for 3-D Global TEC representation. In: Proceedings of the 1998 IGS Analysis Centres Workshop, Darmstadt, pp 285–297Google Scholar
  15. Gao Y, Heroux P, Kouba J (1994) Estimation of GPS receiver and satellite L1/L2 signal delay biases using data from CACS. In: Proceedings of the KIS-94, Banff, pp 109–117Google Scholar
  16. Gao Y, Lahaye F, Héroux P, Liao X, Beck N, Olynik M (2001) Modeling and estimation of C1-P1 bias in GPS receivers. J Geod 74(9):621–626. DOI 10.1007/s001900000117CrossRefGoogle Scholar
  17. Gaposchkin EM, Coster AJ (1993) GPS L1–L2 bias determination. Lincoln Laboratory Technical Report 971 (MIT), MassachusettsGoogle Scholar
  18. Hernandez-Pajares M (2004) IGS Ionosphere WG: an overview. In: Proceedings of the COST 2004, Nice, pp 29–29Google Scholar
  19. Hernández-Pajares M, Juan JM, Sanz J (1999) New approaches in global ionospheric determination using ground GPS data. J Atmos Solar Terr Phys 61:1237–1247CrossRefGoogle Scholar
  20. Jakowsky N, Sardon E, Egler E, Jungstand A, Klahn D (1996) About the use of GPS measurements for ionospheric studies. In: Beutler G, Hein GW, Melbourne WG, Seebr G (eds) GPS trends in precise terrestrial airborne and spaceborne applications. IAG Symposium vol 115. Springer, Berlin Heidelberg New York, pp 335–340Google Scholar
  21. Langley R (1996) Propagation of the GPS signals. In: Kleusberg A, Teunissen P (eds) GPS for geodesy. Springer, Berlin Heidelberg New York, pp 103–140. ISBN 3-540-60785-4Google Scholar
  22. Lanyi GE, Roth T (1988) A comparison of mapped and measured total ionospheric electron content using Global Positioning System and beacon satellite observations. Radio Sci 23:483–492Google Scholar
  23. Leitinger R, Putz E (1988) Ionospheric refraction errors and observables. Atmospheric effects on geodetic space measurements. Monograph 12, School of Surveying, University of New South Wales, Sydney, pp 81–102Google Scholar
  24. Ma XF, Maruyama T, Ma G (2005) Determination of GPS receiver differential biases by neuronal network parameter estimation method. Radio Sci 40:RS1002. DOI 10.1029/2004RS003072CrossRefGoogle Scholar
  25. Mannucci AJ, Wilson BD, Yuan DN, Ho CH, Lindqwister UJ, Runge TF (1998) A global mapping technique for GPS-derived ionospheric total electron content measurements. Radio Sci 33:565–582CrossRefGoogle Scholar
  26. Otsuka Y, Ogawa T, Saito A, Tsugawa T, Fukao S, Miyasaky S (2002) A new method for mapping of total electron content using GPS in Japan. Earth Planets Space 54:63–70Google Scholar
  27. Sardon E, Zarraoa N (1997) Estimation of total electron-content using GPS data: how stable are the differential satellite and receiver instrumental biases? Radio Sci 32:1899–1910CrossRefGoogle Scholar
  28. Sardon E, Rius A, Zarraoa N (1994) Estimation of the transmitter and receiver differential biases and the ionospheric total electron content from Global Positioning System observations. Radio Sci 29:577–586CrossRefGoogle Scholar
  29. Schaer S (1999) Mapping and predicting the Earth’s ionosphere using the Global Positioning System. PhD thesis, Astronomisches Institut, Universität Bern, SwitzerlandGoogle Scholar
  30. Walter T, Blanch J, Rife J (2004) Treatment of biased error distributions in SBAS. J Global Position Syst 3(1–2):265–272CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  • L. Ciraolo
    • 1
  • F. Azpilicueta
    • 2
    Email author
  • C. Brunini
    • 2
    • 3
  • A. Meza
    • 2
    • 3
  • S. M. Radicella
    • 4
  1. 1.Istituto di Fisica Applicata “Carrara” del Consiglio Nazionale delle Ricerche (IFAC-CNR)Sesto Fiorentino (FI)Italy
  2. 2.Facultad de Ciencias Astronómicas y GeofísicasUniversidad Nacional de La PlataLa PlataArgentina
  3. 3.Consejo Nacional de Investigaciones Científicas y TecnológicasBuenos AiresArgentina
  4. 4.Aeronomy and Radiopropagation LaboratoryAbdus Salam International Centre for Theoretical PhysicsTriesteItaly

Personalised recommendations