Abstract
When GPS satellite signals are transmitted through the atmosphere they are affected by the media. In the neutral atmosphere the refraction is a function of pressure, temperature, and humidity along the signal path, and in the GPS positioning process this effect is normally handled by utilising global tropospheric delay models. For high accuracy differential positioning over baselines lengths where the differential effect of the signal delay from the neutral atmosphere is significant, these global models of the signal delay are not sufficiently accurate, and this is especially the case during abnormal weather conditions.
This paper describes a new approach where numerical weather predictions (NWPs) are introduced in the GPS data processing instead of global tropospheric delay models. NWPs are predictions of the meteorological conditions for a given area and epoch in time, and can as such be used for estimating the tropospheric delay for a satellite signal by numerical integration along the signal path through the NWP. For the tests described in this paper, the signal delays are determined as a zenith delay through the NWP combined with a mapping function. This approach is useful for kinematic and shorter static GPS applications. The paper describes the theory of the method, and the applicability of the method is evaluated by analysing position accuracies obtained by introducing NWP-derived signal delays in kinematic and static processing of GPS data. Improved position accuracies are obtained for most of the test scenarios, indicating that the method does have a potential.
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References
Beutler, G., E. Brockmann, R. Dach, P. Fridez, W. Gurtner, U. Hugentobler, J. Johnson, L. Mervart, M. Rothacher, S. Schaer, T. Springer, R. Weber (2000). Bernese GPS Software. Astronomical Institute, University of Berne.
Bevis, M., S. Businger, S. Chriswell, T. A. Herring, R. A. Anthes, C. Rocken, R. H. Ware (1994). GPS Meteorology: Mapping Zenith Wet Delays onto Precipitable Water. Journal of Applied Meteorology, 33:379–386.
Brunner, F. K., M. Gu (1991). An improved model for the dual frequency ionospheric correction of GPS observations. Manuscripta Geodaetica, 16:205–214.
Cannon, M. E. (1997). Carrier Phase Kinematic Positioning: Fundamentals and Applications. In Geodetic Applications of GPS, Lecture Notes for Nordic Autumn School edited by Bo Jonsson. Number 16 in Reports in Geodesy and Geographical Information Systems, National Land Survey of Sweden.
Hopfield, H.S. (1969). Two-quartic Tropospheric Refractivity Profile for Correcting Satellite Data. Journal of Geophysical Research, 74(18): 4487–4499.
Jensen, A. B. O., M. E. Cannon (2000). Performance of Network RTK Using Fixed and Float Ambiguities. Proceedings of the 2000 National Technical Meeting of the Satellite Division of the Institute of Navigation (ION NTM 2000). Pages 797–805.
Jensen, A. B. O. (2002). Numerical Weather Predictions for Network RTK. Publication Series 4, volume 10. National Survey and Cadastre — Denmark.
Johansson, J. M. (1997), Modelling of the Earth Atmos-sphere in Space Geodetic Applications. In Geodetic Applications of GPS, Lecture Notes for Nordic Autumn School edited by Bo Jonsson. Number 16 in Reports in Geodesy and Geographical Information Systems, National Land Survey of Sweden.
Langley, R. (1996). Propagation of the GPS Signal. In Kleusberg, A. and P. J. G. Teunissen (eds) GPS for Geodesy, Lecture Notes in Earth Sciences. Springer-Verlag.
Mendes, V. B. (1999). Modelling the neutral-atmosphere propagation delay in radiometric space techniques. Ph.D. dissertation. Report number 199. Department of Geodesy and Geomatics Engineering, University of New Brunswick, Fredricton.
Niell, A. E. (1996). Global mapping functions for the atmosphere delay at radio wavelengths. Journal of Geophysical Research, 101(B2):3227–3246.
Pany, T., P. Pesec, G. Stangl, (2001). Atmospheric GPS Slant Path Delays and Ray Tracing Through Numerical Weather Models, a Comparison. Physics and Chemistry of the Earth. 26A(3):183–188.
Saastamoinen, J. (1973). Contributions to the Theory of Atmospheric Refraction. Bulletin Geodesique. Printed in three parts, 105:279–298, 106:383–397, 107:13–34.
Sass, B. H., N. W. Nielsen, J. U. Jorgensen, B. Amstrup, M. Kmit (2000). The Operational HIRLAM System at DMI. Scientific Report 00-26. Danish Meteorological Institute. Copenhagen
Schueler, T. (2001). On Ground-based GPS Tropospheric Delay Estimation. Ph.D. thesis, Universitdt der Bundeswehr, München.
Seeber, G. (1993). Satellite Geodesy. Foundations, Methods and Applications. Walter de Gruyter.
Vedel, H., K. S. Mogensen, X.-Y. Huang (2001). Calculation of zenith delays from meteorological data, comparison of NWP model, radiosonde and GPS delays. Physics and Chemistry of the Earth, 26A(6–8):497–502.
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Jensen, A. (2005). Numerical Weather Predictions for GPS Positioning. In: Sansò, F. (eds) A Window on the Future of Geodesy. International Association of Geodesy Symposia, vol 128. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-27432-4_12
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DOI: https://doi.org/10.1007/3-540-27432-4_12
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-24055-6
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