Analysis and Evaluation of Various Tropospheric Modeling Approaches for High-Precision GPS Kinematic Positioning over Medium Ranges and at High Altitude: Case Study
Publication: Journal of Surveying Engineering
Volume 135, Issue 2
Abstract
In global positioning system (GPS) positioning, the tropospheric delay is a systematic error. Mismodeling of the tropospheric delay results in a degradation of the estimated height component, and thus constitutes a limitation to high-accuracy GPS applications. As such, it is obvious that the tropospheric delay should be modeled as accurately as possible. Modeling the tropospheric delay for some applications, such as precise airborne kinematic differential positioning, is further complicated due to the large altitude difference between the ground-based receiver and the airborne roving receiver. This study tests and analyzes three methods for modeling the tropospheric delay, in an attempt to improve the accuracy of the height component for airborne GPS kinematic positioning. As there are several other error sources in GPS, the test and evaluation have to be carefully designed, as any improvements in accuracy due to the use of any tropospheric modeling approaches could be masked by other effects, such as residual orbit errors and ionospheric delays. The analysis is performed for real airborne GPS data and data from a multiple-base station network, and model performance evaluation is based on an independently well-determined aircraft trajectory. Test results show that the estimation of residual tropospheric zenith delay simultaneously with the position parameters after applying the tropospheric delay corrections derived from a network of GPS receivers is seen as the best option with an additional 62% improvement for the height component in terms of standard deviation when compared with results from using a UNB3 tropospheric model only.
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Acknowledgments
The writers are grateful for the airborne GPS data from Associate Professor Dr. O. Øvstedal of the Agricultural University of Norway that made this study possible.
References
Alber, C., Ware, R., Rocken, C., and Braun, J. (2000). “Obtaining single path phase delays from GPS double differences.” Geophys. Res. Lett., 27(17), 2661–2664.
Alves, P., Ahn, Y. W., Liu, J., Lachapelle, G., Wolfe, D., and Cleveland, A. (2004). “Improvements of USCG RTK positioning performance using external NOAA tropospheric corrections integrated with a multiple reference station approach.” Proc., National Technical Meeting, Institute of Navigation, 689–698.
Boon, F. J. G., de Jonge, P. J., and Tiberius, C. C. J. M. (1997). “Precise aircraft positioning by fast ambiguity resolution using improved troposphere modeling.” Proc., 10th Int. Technical Meeting of the Satellite Division of the Institute of Navigation, 1877–1884.
Brown, A., and van Diggelen, F. (1994). “Boundary layer tropospheric effects on airborne on-the-fly ambiguity resolution.” Proc., Int. Symp. on Kinematic Systems in Geodesy, Geomatics & Navigation, 99–108.
Brunner, F., and Welsch, W. (1993). “Effect of the troposphere on GPS measurements.” GPS World, 4(1), 42–51.
Bruton, A. M., et al. (2001). “On the accuracy of kinematic carrier phase DGPS for airborne mapping.” Geomatica, 55(4), 491–507.
Collins, J., and Langley, R. B. (1997). “Estimating the residual tropospheric delay for airborne differential GPS positioning.” Proc., 10th Int. Technical Meeting of the Satellite Division of the Institute of Navigation, 1197–1206.
Collins, J., and Langley, R. B. (1999). “Tropospheric delay prediction for the WAAS user.” GPS World, 10(7), 52–58.
Collins, J., Langley, R. B., and LaMance, J. (1996). “Limiting factors in tropospheric propagation delay error modeling for GPS airborne navigation.” Proc., 52nd Annual Meeting of the Institute of Navigation, 519–528.
Dodson, A. H., Shardlow, P. J., Hubbard, L. C. M., Elgered, G., and Jarlemark, P. O. J. (1996). “Wet tropospheric effects on precise relative GPS height determination.” J. Geodesy, Berlin, 70(4), 188–202.
Grejner-Brzezinska, D. A., Kashani, I., and Wielgosz, P. (2005). “On accuracy and reliability of instantaneous network RTK as a function of network geometry, station separation, and data processing strategy.” GPS Solutions, 9(3), 179–193.
Hu, G. R., Khoo, H. S., Goh, P. C., and Law, C. L. (2003). “Development and assessment of virtual reference stations for RTK positioning.” J. Geodesy, Berlin, 77(5–6), 292–302.
Hu, G. R., Ovstedal, O., Featherstone, W. E., Castleden, N., Earls, C., and Abbey, D. A. (2008). “Using the virtual reference stations (VRS) concept for long-range airborne GPS kinematic positioning.” Surv. Rev., 40(307), 83–91.
Janes, H. W., Langley, R. B., and Newby, S. P. (1991). “Analysis of tropospheric delay prediction models: Comparisons with ray-tracing and implications for GPS relative positioning.” Bull. Geod., 65(3), 151–161.
Kashani, I., Grejner-Brzezinska, D. A., and Wielgosz, P. (2004). “Toward instantaneous network-based real-time kinematic GPS over distance.” Proc., 60th Annual Meeting of Institute of Navigation, 679–685.
Kim, D., Bisnath, S., Langley, B. R., and Dare, P. (2004). “Performance of long-baseline real-time kinematic applications by improving tropospheric delay modeling.” Proc., 17th Int. Technical Meeting of the Satellite Division of the U.S. Institute of Navigation, 1414–1422.
Kjorsvik, N., Øvstedal, O., Svendsen, J. G. G., and Blankenberg, L. E. (2003). “Evaluation of a multi-base-station differential approach.” Proc., 16th Int. Technical Meeting of the Satellite Division of the U.S. Institute of Navigation, 1381–1389.
Leandro, R., Santos, M., and Langley, R. B. (2006). “UNB neutral atmosphere models: Development and performance.” Proc., ION NTM 2006, the 2006 National Technical Meeting of the Institute of Navigation, 564–577.
Leick, A. (2004). GPS satellite surveying, 3rd Ed., Wiley, New York.
McCarthy, D. D., and Petit, G. (2004). “IERS Conventions (2003).” IERS Technical Note No. 32, Verlag des Bundesamts für Kartographie und Geodäsie, Frankfurt am Main, Germany.
Mendes, V. (1999). “Modeling the neutral atmosphere propagation delay in radiometric space techniques.” Ph.D. dissertation, Technical Rep. No. 199, Department of Geodesy and Geomatics Engineering. Univ. of New Brunswick, New Brunswick, Conn.
Mendes, V. B., Collins, J. P., and Langley, R. B. (1995). “The effect of tropospheric propagation delay errors in airborne GPS precision positioning.” Proc., 8th Int. Technical Meeting of the Satellite Division of the Institute of Navigation, 1681–1689.
Mendes, V. B., and Langley, R. B. (1994). “A comprehensive analysis of mapping functions used in modeling tropospheric propagation delay in space geodetic data.” Proc., KIS94, Int. Symp. on Kinematic Systems in Geodesy, Geomatics and Navigation, 87–98.
Musa, T. A., Wang, J., Rizos, C., Lee, Y. J., and Mohamed, A. (2004). “Mitigating residual tropospheric delay to improve user’s network-based positioning.” J. Global Positioning Systems, 3(1–2), 322–330.
Neill, A. (1996). “Global mapping functions for the atmosphere delay at radio wavelengths.” J. Geophys. Res., 101(B2), 51–59.
Pattinson, M., Dodson, A., and Moore, T. (2002). “Tropospheric delay estimation from a moving GPS receiver.” Proc., 15th Int. Technical Meeting of the Satellite Division of the U.S. Institute of Navigation, 2294–2303.
Saastamoinen, J. (1973). “Contributions to the theory of atmospheric refraction.” Bull. Geod., 105, 279–298.
Shi, J., and Cannon, M. E. (1995). “Critical error effects and analysis in carrier phase-based airborne GPS positioning over large areas.” Bull. Geod., 69(4), 261–273.
Sonntag, J. G., Martin, C. F., and Krabill, W. B. (1995). “Ambiguity resolution over long baselines for airborne differential GPS positioning.” Proc., 8th Int. Technical Meeting of the Satellite Division of the U.S. Institute of Navigation, 1117–1125.
Tiemeyer, B., Cannon, M. E., Lachapella, G., and Schanzer, G. (1994). “Satellite navigation for high precision aircraft navigation with emphasis on atmospheric effects.” Proc., PLANS’94, IEEE, New York, 394–401.
Vollath, U., Brockmann, E., and Chen, X. (2003). “Troposphere: Signal or noise?” Proc., 16th Int. Technical Meeting of the Satellite Division of the U.S. Institute of Navigation, 1709–1717.
Wübbena, G., Bagge, A., Seeber, G., Böder, V., and Hankemeier, P. (1996). “Reducing distance dependent errors for real-time precise DGPS applications by establishing reference station networks.” Proc., 9th Int. Technical Meeting of the Satellite Division of the U.S. Institute of Navigation, 1845–1852.
Zhang, J., and Lachapelle, G. (2001). “Precise estimation of residual tropospheric delays using a regional GPS network for real-time kinematic applications.” J. Geodyn., 75(5–6), 255–266.
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© 2009 ASCE.
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Received: Oct 25, 2007
Accepted: Sep 26, 2008
Published online: May 1, 2009
Published in print: May 2009
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