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The impact of the atmosphere and other systematic errors on permanent GPS networks

  • S. Schaer
  • G. Beutler
  • M. Rothacher
  • E. Brockmann
  • A. Wiget
  • U. Wild
Part of the International Association of Geodesy Symposia book series (IAG SYMPOSIA, volume 121)

Abstract

The Swiss Federal Office of Topography is currently building up the Automated GPS Network Switzerland, called AGNES. This GPS network will serve various purposes, like national surveying, engineering surveying, navigation, meteorology, and research.

For wide-area differential GPS (WADGPS), in particular precise real-time positioning using the GPS phase data of one or more reference stations of the AGNES network, one may expect that atmospheric refraction plays the crucial role, since the reference stations may be rather widely separated in Switzerland, typically by 50-100 km. This assumes that orbits and “absolute” tropospheric refraction for at least one of the sites are known with sufficient precision.

In the time period of the next solar maximum, the ionospheric refraction will probably be the most crucial error source, in particular for resolving the initial phase ambiguities, which is mandatory when aiming at a coordinate accuracy on the centimeter level. Nowadays, global and regional total electron content (TEC) maps, like those produced by the Center for Orbit Determination in Europe (CODE), are available and may be used to model the mean ionospheric refraction. However, on time scales of few minutes, ambiguity resolution usually suffers from short-term ionospheric fluctuations which are not accounted for by such TEC maps.

Significant height differences with respect to the nearest reference stations may also occur, especially in mountainous areas like Switzerland. This implies that not perfectly modeled tropospheric refraction may cause biases too.

We study the impact of tropospheric as well as ionospheric biases on WADGPS results and investigate whether it is possible to extract atmospheric information from networks of the AGNES-type for correcting data of mobile GPS receivers in (near) real time.

Keywords

Permanent GPS networks WAD-GPS atmosphere modeling 

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References

  1. Beutler, G., W. Gurtner, M. Rothschec, U. Wild, and E. Frei (1990). Relative Static Positioning with the Global Positioning System: Basic Technical Considerations. In: Global Positioning System: An Overview, IAG Symposia, No. 102, pp. 1–23.Google Scholar
  2. Beutler, G., II. Mueller, RE. Neilan (1956). The International GPS Service for Geodynamics (IGS): The Story. In:International Association of Geodesy Symposium, No. 115, GPS 7henda in Precise Terrestrial, Airborne, and Spaceborne Applications, pp. 3–13, Springer-Verlag, ISBN 3-540-60872-6.Google Scholar
  3. Kouba, J. and J. Popelar (1994). Modern Geodetic Reference Frames for Precise Satellite Positioning and Navigation. In:Proceedings of the, KIS 94 International Symposium on Kinematic Systems in Geodesy.Google Scholar
  4. Van der Marel, H. and CD. de Jong (1999). Active GPS Reference System for the Netherlands. In: Physics and Chemistry of the Earth(in preparation).Google Scholar
  5. Rothacher, M. and L. Mervart (1996). Bemese GPS Software, Version 4.0, Astronomical Institute, University of Berne.Google Scholar
  6. Schaer, S . (1999). Mapping and Predicting the Earth’s Ionosphere Using the Global Positioning System. Ph.D. Theses Series,Astronomical Institute, University of Berne.Google Scholar
  7. Wanninger, L . (1999). Der Einfluss ionosphärischer Störungen auf die präziae GPS-Positionierung mit Hilfe virtueller Referemstationen. In:Zeitschrift für Yermesaungsweaen(in press).Google Scholar
  8. Zumberge, JF., DE. Fulton, and RE. Neilan (1997). International GPS Service for Geodynam–ics, 1996 Annual Report.IGS Central Bureau, Jet Propulsion Laboratory.Google Scholar

Copyright information

© SPringer-Verlag Berlin Heidelberg 2000

Authors and Affiliations

  • S. Schaer
    • 1
  • G. Beutler
    • 1
  • M. Rothacher
    • 1
  • E. Brockmann
    • 2
  • A. Wiget
    • 2
  • U. Wild
    • 2
  1. 1.Astronomical InstituteUniversity of BerneBernSwitzerland
  2. 2.Swiss Federal Office of TopographyWabernSwitzerland

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