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Broadcast vs. precise GPS ephemerides: a historical perspective

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Abstract

The Navstar Global Positioning System (GPS) Operational Control Segment (OCS) generates predicted satellite ephemerides and clock corrections that are broadcast in the navigation message and used by receivers to estimate real-time satellite position and clock corrections for use in navigation solutions. Any errors in these ephemerides will directly impact the accuracy of GPS based positioning. This paper compares the satellite position computed using broadcast ephemeredes with the precise position provided by the International GPS Service for Geodynamics (IGS) Final Orbit solution. Similar comparisons have been undertaken in the past, but for only short periods of time. This paper presents an analysis of the GPS broadcast ephemeris position error on a daily basis over the entire operational lifetime of the GPS system. The comparison was undertaken from 14 November 1993 through to 31 December 2002. The statistics of these errors were also analyzed.

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Acknowledgements

The authors would like to thank Major Dave Goldstein (formerly) at the GPS Joint Program Office for his sponsorship of this research. He originated the idea of conducting the long-term comparison of broadcast and precise ephemeris given in this paper.

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Authors and Affiliations

  1. Air Force Institute of Technology, AFIT/ENG 2950 P Street Bldg. 640, Wright-Patterson AFB, OH , 45433, USA

    David L. M. Warren & John F. Raquet

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  1. David L. M. Warren
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  2. John F. Raquet
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Correspondence to John F. Raquet.

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Disclaimer: The views expressed in this article are those of the authors and do not reflect the official policy or position of the Royal Australian Air Force, Australian Defense Organization, Australian government, United States Air Force, US Department of Defense, or the US Government.

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Warren, D.L.M., Raquet, J.F. Broadcast vs. precise GPS ephemerides: a historical perspective. GPS Solutions 7, 151–156 (2003). https://doi.org/10.1007/s10291-003-0065-3

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  • DOI: https://doi.org/10.1007/s10291-003-0065-3

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