Hostname: page-component-78c5997874-t5tsf Total loading time: 0 Render date: 2024-11-13T07:09:21.905Z Has data issue: false hasContentIssue false

A Combined GPS/GLONASS Navigation Algorithm for use with Limited Satellite Visibility

Published online by Cambridge University Press:  07 October 2009

Changsheng Cai*
Affiliation:
(University of Calgary)
Yang Gao
Affiliation:
(University of Calgary)
*

Abstract

Navigation users will significantly benefit from the combined use of GPS and GLONASS due to the improved reliability, availability and accuracy especially in an environment with limited satellite visibility, such as in urban or mountainous areas. But in such situations the visible satellite number is often still insufficient to obtain a position solution even if both GPS and GLONASS measurements are used. This is partly because at least five visible satellites are required to determine a position due to an offset between the timescales of GPS and GLONASS to be solved. In this paper, an algorithm has been proposed to obtain a position solution with only four visible GPS/GLONASS satellites. In addition to the data from IGS stations, an experiment was also conducted to assess the proposed algorithm. The results indicate that using the proposed algorithm with only four GPS/GLONASS satellites a position solution could be obtained at the cost of a slight accuracy loss.

Type
Research Article
Copyright
Copyright © The Royal Institute of Navigation 2009

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

Bauch, A., Piester, D., Moudrak, A. and Petit, G. (2004). Time Comparisons between USNO and PTB: A Model for the Determination of the Time Offset between GPS Time and the Future Galileo System Time. Proceedings of IEEE International Ultrasonics, Ferroelectrics and Frequency Control Joint 50th Anniversary Conference, pp. 334340. 2004.CrossRefGoogle Scholar
Cai, C. and Gao, Y. (2008). Estimation of GPS/GLONASS System Time Difference with Application to PPP, Proceedings of Institute of Navigation GNSS 2008, September 16–19, 2008, Savannah, Georgia, USA.Google Scholar
Garmin Ltd. (2005). An Introduction to Using a Garmin GPS with Paper Maps for Land Navigation. October, 2005. Http://www.garmin.com, accessed on March 1, 2008.Google Scholar
Habrich, H. (1999). Geodetic Applications of the Global Navigation Satellite System (GLONASS) and of GLONASS/GPS Combinations. PhD Thesis, University of Berne.Google Scholar
ICD-GLONASS (2002). Global Navigation Satellite System GLONASS Interface Control Document, version 5.0, Moscow.Google Scholar
ICD-GPS (2000). Interface Control Document – Navstar GPS Space Segment/Navigation User Interfaces, ICD-GPS-200C.Google Scholar
Kang, J., Lee, Y., Park, J. and Lee, E. (2002). Application of GPS/GLONASS Combination to the Revision of Digital Map. Proceedings of FIG XXII International Congress, Washington, D.C. USA, April 19–26, 2002.Google Scholar
Langley, R. B. (1997). GLONASS: Review and Update. GPS World, Vol. 8, No. 7, pp. 4651. 1997.Google Scholar
Moudrak, A., Konovaltsev, A., Furthner, J., Hammesfahr, J., Bauch, A., Defraigne, P., Bedrich, S. and Schroth, A. (2005). Interoperability on Time GPS-Galileo Offset Will Bias Position. GPS World, March, Vol. 16, No. 3, pp. 2432, 2005.Google Scholar
Petrovski, I. G., Engelsberg, V. and Babakov, V. (2008). Expert Advice-GLONASS Business Prospects. GPS World, March, Vol. 19, No. 3, pp. 1215. 2008.Google Scholar
Revnivykh, S. (2008). GLONASS May Broadcast CDMA Signals from Future Satellites. GPS World, February 26, 2008. http://www.gpsworld.com, accessed on March 1, 2008.Google Scholar
Vanschoenbeek, I., Bonhoure, B., Boschetti, M. and Legenne, J. (2007). GNSS Time Offset Effect on GPS-Galileo Interoperability Performance. InsideGNSS, pp. 6070, September/October, 2007.Google Scholar