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GPS Solutions

, Volume 17, Issue 3, pp 357–369 | Cite as

Determining receiver biases in GPS-derived total electron content in the auroral oval and polar cap region using ionosonde measurements

  • David R. Themens
  • P. T. Jayachandran
  • R. B. Langley
  • J. W. MacDougall
  • M. J. Nicolls
Original Article

Abstract

Global Positioning System (GPS) total electron content (TEC) measurements, although highly precise, are often rendered inaccurate due to satellite and receiver differential code biases (DCBs). Calculated satellite DCB values are now available from a variety of sources, but receiver DCBs generally remain an undertaking of receiver operators and processing centers. A procedure for removing these receiver DCBs from GPS-derived ionospheric TEC at high latitudes, using Canadian Advanced Digital Ionosonde (CADI) measurements, is presented. Here, we will test the applicability of common numerical methods for estimating receiver DCBs in high-latitude regions and compare our CADI-calibrated GPS vertical TEC (vTEC) measurements to corresponding International GNSS Service IONEX-interpolated vTEC map data. We demonstrate that the bias values determined using the CADI method are largely independent of the topside model (exponential, Epstein, and α-Chapman) used. We further confirm our results via comparing bias-calibrated GPS vTEC with those derived from incoherent scatter radar (ISR) measurements. These CADI method results are found to be within 1.0 TEC units (TECU) of ISR measurements. The numerical methods tested demonstrate agreement varying from within 1.6 TECU to in excess of 6.0 TECU when compared to ISR measurements.

Keywords

Global Positioning System (GPS) Ionosonde Total electron content (TEC) Polar ionosphere Receiver biases Differential code biases 

Notes

Acknowledgments

Infrastructure funding for CHAIN is provided by the Canada Foundation for Innovation (CFI) and the New Brunswick Innovation Foundation (NBIF). CHAIN operation is conducted in collaboration with the Canadian Space Agency (CSA). We thank the Natural Sciences and Engineering Research Council (NSERC) for the summer research funding received. ISR data were provided via the Madrigal database at SRI International.

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Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • David R. Themens
    • 1
  • P. T. Jayachandran
    • 1
  • R. B. Langley
    • 2
  • J. W. MacDougall
    • 3
  • M. J. Nicolls
    • 4
  1. 1.Department of PhysicsUniversity of New BrunswickFrederictonCanada
  2. 2.Department of Geodesy and Geomatics EngineeringUniversity of New BrunswickFrederictonCanada
  3. 3.Department of Physics and AstronomyUniversity of Western OntarioLondonCanada
  4. 4.Center for Geospace StudiesSRI InternationalMenlo ParkUSA

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