GPS Water Vapor Estimation Using Interpolated Surface

Zhengdong Bai, Yanming Feng

Cooperative Research Centre for Satellite Systems, Queensland University of Technology, GPO Box 2434, Q4001, Australia.

DOI:                 

Abstract

The existing GPS tracking networks established primarily for surveying, geodesy and navigation purposes may also be used for meteorology studies. This research uses hourly surface temperature and pressure (T & P) observations from Australia for GPS Precipitable Water Vapor (PWV) estimation. The paper outlines the basic meteorological data requirements, and presents experimental results to show the comparison between interpolated and observed T and P values, and agreement between GPS-PWV estimates, using surface meteorological data and radiosonde PWV results. Data analysis of 36 data points in the Victoria region has demonstrated that the Ordinary Kriging method is preferable to pressure interpolation, resulting in an overall standard deviation of 0.40 mbar in pressure or 0.15mm in PWV estimation. We use the interpolated T and P measurements for four Australian IGS GPS sites to estimate GPS-PWV and compare against the radiosonde PWV results for the closely located radiosonde observations. 195 comparisons from all the sites have shown that GPS-PWV estimates agree with the Rad- PWV solutions at an average mean difference of –0.604 mm and RMS of 1.74mm for the tested stations. This agreement level is considered very reasonable. The experimental study shows a possible way to develop GPS meteorology and applications with the existing meteorological data network. This could save significant costs in installation of GPS-Met sensors.

Keywords

GPS meteorology, perceptible water vapor, pressure, interpolation, radiosondes.

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Black, H. D. (1978) An easily implemented algorithm for the tropospheric range correction, Journal of Geophysical Research, Vol.83, No.4, pp.1825-1828.
[2]	Dorsel, D.S., and T. LaBreche (1997) Kriging Http://www.cee.vt.edu/program_areas/environmental/teach /smprimer/kriging/kriging.html, 1 May 2002, 10pp.
[3]	Feng Y., Z. Bai, P. Fang and A.Williams (2001) GPS Water Vapor Experimental Results From Observations of the Australian Regional GPS Network (ARGN), 2001 – A Spatial Odyssey : 42nd Australian Surveyors Congress, 18 pp.
[4]	Hopfield, H.S. (1971) Tropospheric effect on electromagnetically measured range: Prediction from surface weather data, Radio Science, Vol. 6, No.3, pp.357-367.
[5]	Jarvis, C.H., and N. Stuart (2001) A comparison among strategies for interpolating maximum and minimum daily air temperatures. Part II: The interaction between number of guiding variables and the type of interpolation method, Journal of Applied Meteorology, 40, pp.1075-1084.
[6]	Klein Baltink, H., H.J.P. Derks, A.C.A.P. van Lammeren, B.A.C. Ambrosius, A.G.A. van der Hoeven, H. van derMarel, F. Kleijer, and A.J.M. K鰏ters (1999) GPS WaterVapor Meteorology, Beleids Commissie Remote Sensing (BCRS), Chapter 2: Water Vapor from GPS Troposheric Delay Estimates, pp.3-11.
[7]	Liu, Y. (2000) Remote Sensing of Atmospheric Water Vapor Using GPS Data in the Hong Kong Region, Department of Land Surveying & Geo-Informatics, The Hong Kong Polytechnic Unversity.
[8]	Liu, Y., Y. Chen and H. Baki Iz (2000) Precision of precipitable water vapor from radiosonde data for GPS solutions, Geomatica, Vol. 54, No. 2, pp. 171-175.
[9]	MIT and SIO (2000) Documentation for the GAMIT GPS analysis software, Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, and Scripts Institution of Oceanography, University of California at San Diego.
[10]	Saastamoinen, J. (1973) Contributions to the theory of atmospheric refraction Part II, Refraction corrections in satellite geodesy, Bulletin Geodesique, No. 107, pp.13-34.
[11]	Van der Marel, H. (2000) GPS Puntsbepaling, Lecture series, TUDelft Department of Geodesy section of Mathematical Geodesy and Positioning.
[12]	Wackernagel, H. (1998) Multivariate Geostatistics, Springer-Verlag, 291 pp.