Abstract
Numerical weather models (NWM) have become an important source of atmospheric data for modeling error sources in geodetic positioning. One example of this is the development of the Vienna Mapping Functions (VMF1) and ray-traced zenith delays which are derived from the European Centre for Medium-range Weather Forecasts (ECMWF) datasets. These products are provided on an operational basis through the GGOS Atmosphere project. In general, relatively little consideration has been given to the choice of NWM on the derived mapping functions and zenith delay products. In this investigation we compare the gridded-VMF1 mapping functions and ray-traced zenith delays derived from the ECMWF to equivalent products derived by ray-tracing through the National Center for Environmental Prediction (NCEP) Reanalysis model. We have chosen to compare the gridded version of these products as they are available for any location on Earth, rather than only specific stations and have been shown to be essentially equivalent in terms of accuracy. This paper also includes a discussion about a systematic production of gridded-VMF1 and ray-traced zenith delays derived from the NCEP datasets (and from the Canadian Meteorological Center GEM model) on an operational basis. The benefits of the service would include: (1) a backup in the event of the ECMWF VMF1 or zenith delays being unavailable; (2) greater compatibility with other NWM derived corrections, such as atmospheric pressure loading and; (3) the availability of tropospheric delay products derived from an independent source and ray-tracing algorithms should provide more robustness for combination products which use these models.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
Boehm J, van Dam T (2009) Modeling deficiencies and modeling based on external data. In: Second GGOS unified analysis workshop, IERS, Grand Hyatt, 11–12 December (oral presentation)
Boehm J, Niell AE, Tregoning P, Schuh H (2006a) Global Mapping Function (GMF): a new empirical mapping function based on numerical weather model data. Geophys Res Lett 33:L07304. doi:10.1029/2005GL025546
Boehm J, Werl B, Schuh H (2006b) Troposphere mapping functions for GPS and very long baseline interferometry from European Centre for medium-range weather forecasts operational analysis data. J Geophys Res 111:B02406. doi:10.1029/2005JB003629
Boehm J, Kouba J, Schuh H (2008) Forecast Vienna mapping functions 1 for realtime analysis of space geodetic observations. J Geodesy 83(5):397–401. doi:10.1007/s00190-008-0216-y
Dow JM, Neilan RE, Rizos C (2009) The international GNSS Service in a changing landscape of global navigation satellite systems. J Geodesy 83:191–198. doi:10.1007/s00190-008-0300-3
Fund F, Morel L, Mocquet A (2009) Discussion and recommendations about the height correction for a priori zenith hydrostatic delays derived from ECMWF data [on-line]. www.hg.tuwien.ac.at/~ecmwf1/Reducing_ECMWF_ZHDs.pdf
Herring TA (1992) Modelling atmospheric delays in the analysis of space geodetic data. In: de Munck JC, Th Spoelstra TA (eds) Proceedings of the symposium refraction of transatmospheric signals in Geodesy, No. 36, Netherlands Geodetic Commission, The Hague, 19–22 May, pp. 157–164
Kouba J (2008) Implementation and testing of the gridded Vienna Mapping Function 1 (VMF1). J Geodesy 82(4):193–205. doi:10.1007/s00190-007-0170-0
Marini JW (1972) Correction of satellite tracking data for an arbitrary tropospheric profile. Radio Sci 7(2):223–231. doi:10.1029/RS007i002p00223
Niell AE (1996) Global mapping functions for the atmosphere delay at radio wavelengths. J Geophys Res 101(B2):3227–3246. doi:10.1029/95JB03048
Nievinski FG (2009) Ray-tracing options to mitigate the neutral atmosphere delay in GPS. M.Sc.E. Thesis, Department of Geodesy and Geomatics Engineering technical report no. 262, University of New Brunswick, Fredericton, New Brunswick, 232 pp
Nievinski FG, Santos MC (2010) Ray-tracing options to mitigate the neutral atmosphere delay in GPS. Geomatica 64(2):191–207
Petit G, Luzum B (eds) (2010) IERS conventions (2010) (IERS technical note; 36). Verlag des Bundesamts für Kartographie und Geodäsie, Frankfurt am Main, 179 pp
Saastamoinen J (1972) Atmospheric correction for the troposphere and stratosphere in radio ranging of satellites. In: Henriksen SW, Mancini A, Chovitz BH (eds) The use of artificial satellites for Geodesy, vol. 15 of Geophysical monograph series. American Geophysical Union, Washington, DC, pp 247–251. ISBN 0-87590-015-1
Teke K, Böhm J, Nilsson T, Schuh H, Steigenberger P, Dach R, Heinkelmann R, Willis P, Haas R, García-Espada S, Hobiger T, Ichikawa R, Shimizu S (2011) Multi-technique comparison of troposphere zenith delays and gradients during CONT08. J Geodesy 85(7):395–413. doi:10.1007/s00190-010-0434-y
Tesmer V, Boehm J, Heinkelmann R, Schuh H (2007) Effect of different tropospheric mapping functions on the TRF, CRF and position time-series estimated from VLBI. J Geodesy 81:409–421. doi:10.1007/s00190-006-0126-9
Urquhart L (2010) Assessment of tropospheric slant factor models: comparison with three dimensional ray-tracing and impact of geodetic positioning. M.Sc.E thesis, Dept of Geodesy and geomatics Engineering technical report 275, University of New Brunswick, Fredericton, 166 pp
Acknowledgments
The authors acknowledge Matthias Madzak (TU Vienna) for processing the VLBI results, the weather agencies (ECMWF, NCEP and CMC) for providing access to the NWM data, and Natural Sciences and Engineering Research Council of Canada (NSERC) and the Austrian Science Fund (FWF, project P20902) for funding the research. Dow et al. 2009 is kindly acknowledged for the IGS products
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2014 Springer-Verlag Berlin Heidelberg
About this paper
Cite this paper
Urquhart, L., Santos, M.C., Nievinski, F.G., Böhm, J. (2014). Generation and Assessment of VMF1-Type Grids Using North-American Numerical Weather Models. In: Rizos, C., Willis, P. (eds) Earth on the Edge: Science for a Sustainable Planet. International Association of Geodesy Symposia, vol 139. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-37222-3_1
Download citation
DOI: https://doi.org/10.1007/978-3-642-37222-3_1
Published:
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-642-37221-6
Online ISBN: 978-3-642-37222-3
eBook Packages: Earth and Environmental ScienceEarth and Environmental Science (R0)