Hostname: page-component-cd9895bd7-dzt6s Total loading time: 0 Render date: 2024-12-27T22:30:42.115Z Has data issue: false hasContentIssue false
  • English
  • Français

Improving Ambiguity Resolution Rate with an Accurate Ionospheric Differential Correction

Published online by Cambridge University Press:  22 December 2008

Mardina Abdullah ,
Hal J. Strangeways  and
David M. A. Walsh
Mardina Abdullah*
Affiliation:
(Universiti Kebangsaan Malaysia)
Hal J. Strangeways
Affiliation:
(University of Leeds)
David M. A. Walsh
Affiliation:
(University of Leeds)
*
(Email: mardina@vlsi.eng.ukm.my)
Get access Rights & Permissions [Opens in a new window]

Abstract

Ambiguity resolution is essential for precise range determination. As it is difficult to process, a good ionospheric model is essential to get unambiguous results or to reduce time to solve the ambiguities. In this paper, a developed model to determine the differential ionospheric error to sub-centimetre accuracy is described. As a function of elevation angle and TEC, the model is applicable at any location and only requires a single frequency receiver provided the TEC over the reference station is known. It has been evaluated using real GPS measurements at spaced stations in Glasgow (UK) and Stirling (UK), where the results showed good correlation. It was found that the variance ratio and reference variance of the ambiguity resolution rate and the quality of the differential positioning solution are improved. Significant improvements of more than 50% have also been found by correcting the differential ionospheric delay in the measurements for the estimated positions.

Keywords

Ambiguity resolutionionosphereGPSTEC
Type
Research Article
Information
The Journal of Navigation , Volume 62 , Issue 1 , January 2009 , pp. 151 - 166
Copyright
Copyright © The Royal Institute of Navigation 2008

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Abdullah, M., Strangeways, H. J. and Walsh, D. M. A. (2003). Accurate ionospheric error correction for differential GPS. Proceedings of the 12 thInternational Conference on Antennas and Propagation, Exeter, UK.CrossRefGoogle Scholar
Abdullah, M., Strangeways, H. J. and Walsh, D. M. A. (2007). Effects of ionospheric horizontal gradients on differential GPS. Acta Geophysica, 55(4), 509–523.CrossRefGoogle Scholar
Estey, L. H., Meertens, C. M. (1999). TEQC: the multi-purpose toolkit for GPS/GLONASS data. GPS Solutions, 3(1), 42–49.CrossRefGoogle Scholar
Georgiadou, Y. and Kleusberg, A. (1988). On carrier signal multipath effects in relative GPS positioning. Manuscripta Geodaetica, 13(3), 172–179.Google Scholar
Gherm, V. E., Zernov, N. N. and Strangeways, H. J. (2001). Effect of ionospheric scintillations on signal coherency over spaced paths for transionospheric propagation. Proceeding of the 11 thInternational Conference on Antenna and Propagation, Manchester, UK.CrossRefGoogle Scholar
Goad, C. (1990). Optimal filtering of pseudoranges and phases from single-frequency GPS receivers. Journal of Navigation, 37(3), 191–204.Google Scholar
Gurtner, W. (2001). RINEX: The Receiver Independent Exchange Format Version 2.10. Available at http://www.ngs.noaa.gov/CORS/Rinex2.html, accessed on 28 January 2008.Google Scholar
Hugentobler, U., Schaer, S. and Fridez, P. (2001). Bernese GPS Software Manual Version 4.2. Bern: Astronomical institute, University of Berne.Google Scholar
International GPS Service (IGS) product/data. (2005). Available at http://igscb.jpl.nasa.gov/components/prods.html, accessed 28 January 2008.Google Scholar
Ioannides, R. T. and Strangeways, H. J. (2002). Rigorous calculation of ionospheric effects on GPS Earth-Satellite paths using a precise path determination method. Acta Geodaetica et Geophysica, 37, 281–292.Google Scholar
Klobuchar, J. A. and Kunches, J. M. (2001). Eye on the ionosphere: correction methods for GPS ionospheric range delay. GPS Solutions, 5(2), 91–92.CrossRefGoogle Scholar
Leick, A. (2004). GPS Satellite Surveying. Wiley, New Jersey.Google Scholar
Seeber, G. (2003). Satellite Geodesy. Walter de Gruyter, Berlin.CrossRefGoogle Scholar
Strangeways, H. J. (2000). Effect of horizontal gradients on ionospherically reflected or transionospheric paths using a precise homing-in method. Journal of Atmospheric and Terrestrial Physics, 62(15), 1361–1376.CrossRefGoogle Scholar
Teunissen, P. J. G. and Kleusberg, A. (1998). GPS for Geodesy. Springer, Berlin.CrossRefGoogle Scholar
Trimble. (1994). WAVE software user's guide. Sunnyvale, CA, USA: Trimble Navigation Limited.Google Scholar
Wanninger, L. and May, M. (2000). Carrier phase multipath calibration of GPS reference stations. Proceeding of ION GPS 2000, Salt Lake City, UT, USA.Google Scholar
Wanninger, L. (1993) Effects of equatorial ionosphere on GPS. GPS World, July, 48–54.Google Scholar