Abstract
The difference between the heights of the VLBI and GPS antennas at Westford as found in ITRF96 differs from the optical survey value by approximately 3 cm. The height of the GPS antenna is, however, a function of the minimum elevation angle cutoff with a sensitivity of approximately -3 mm/°. A sample of other Dorne Margolin choke ring antennas of the global GPS network shows similar sensitivity, while two Trimble antennas have more severe sensitivities which are of the opposite sign. Until the elevation dependent phase error can be measured in situ there is no way to determine the absolute height of the current GPS antennas. As a consequence, the scale of the Terrestrial Reference Frame cannot be determined by GPS to better than several parts per billion, and the heights of individual sites are uncertain at the several centimeter level.
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References
Carpenter Troy V., Vaughn E. Nelson: “Westford-Haystack Check Survey”, AlliedSignal Technical Services Corporation note, Feb 1997.
Carter W. E., Rogers A. E. E., Counselman C. C. III, Shapiro I. I.,: “Comparison of Geodetic and Radio Interferometric Measuerements of the Haystack-Westford Base Line Vector”, JGR, Vol 85, No B5,2685-2687, May 10, 1980.
Elósegui P., Davis J.L., Jaldehag R.T.K., Johansson J.M., Niell A.E., Shapiro I.I.: “Geodesy Using the Global Positioning System: The Effects of Signal Scattering on Estimates of Site Position”, JGR, Vol. 100, No. B7,9921–9934, June 10, 1995.
Jaldehag R.T.K., Johansson J.M., Rönnäng, Elósegui P., Davis J.L., Shapiro I.I., Niell A.E.: “Geodesy Using the Swedish Permanent GPS Network: Effects of Signal Scattering on Estimates of Relative Site Positions”, JGR Vol 101, No. B8, 17,841–17,860, August 1996.
Niell A.E.: “Near-field Problems for GPS Antennas”, in The Global Positioning System for the Geosciences, National Academy Press, Washington, D.C. 1997.
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© 1997 Springer-Verlag Berlin · Heidelberg
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Niell, A.E. (1997). Westford VLBI to GPS Vertical Tie and Implications for the TRF. In: Rummel, R., Drewes, H., Bosch, W., Hornik, H. (eds) Towards an Integrated Global Geodetic Observing System (IGGOS). International Association of Geodesy Symposia, vol 120. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-59745-9_36
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DOI: https://doi.org/10.1007/978-3-642-59745-9_36
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