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The Astrometric Possibilities of Very-Long-Baseline Interferometry

Published online by Cambridge University Press:  04 August 2017

D. S. Robertson*
Affiliation:
National Geodetic Survey, Charting and Geodetic Services National Ocean Service, NOAA Rockville, Maryland 20852

Extract

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In the application of Very-Long-Baseline Interferometry (VLBI) to astrometric problems the fundamental observable is the difference in the arrival times of a wavefront at two widely separated receiving stations. Since the radio sources being observed are sufficiently distant that the arriving wavefront can be considered to be a plane wave, the differential arrival time is a measure of the component of the baseline in the direction of the source. Equivalently, if the baseline is known, the differential arrival time is sufficient to determine a circle on the sky containing the source. It is easy to show that a minimum of ten observations distributed among three different sources is sufficient to determine all of the source coordinates and the baseline coordinates simultaneously (Robertson, 1975).

Type
II. Radio Astrometry
Copyright
Copyright © Reidel 1986 

References

Annual Report for 1981, 1982, 185 pp, Bureau International de l'Heure, Paris.Google Scholar
Calame, O., ed., 1982, “High Precision Earth Rotation and Earth-Moon Dynamics”, D. Reidel Co., Dordrecht, Holland.CrossRefGoogle Scholar
Carter, W.E. and, Robertson, D.S., 1982, “Geodynamic Measurements from the HRAS-Westford POLARIS Radio Interferometer”, in Proceedings of the General Meeting of the IAG, pp. 146156, Tokyo.Google Scholar
Carter, W.E., Robertson, D.S., Tapley, B.D., Schutz, B.E., Eanes, R.J., and Lufeng, Miao, 1984, Science, (in press).Google Scholar
Carter, W.E., Rogers, A.E.E., Counselman, C.C., and, Shapiro, I.I., 1980, J. Geophys. Res., 85, No. B5, pp. 26852687.CrossRefGoogle Scholar
Carter, W.E. and, Strange, W.E., 1979, Tectonophysics, 52, pp. 3946.CrossRefGoogle Scholar
Cotton, W.D., 1980, “Source Structure Corrections to the Geodetic Very Long Baseline Interferometry Observables”, in Radio Interferometry Techniques for Geodesy, NASA Conference Publication 2115, pp. 193198.Google Scholar
Robertson, D.S., 1975, “Geodetic and Astrometric Measurements with Very Long Baseline Interferometry”, , pp. 1820, M.I.T., Cambridge, Mass., also available as NASA GSFC X-document # X-922-77-228.Google Scholar
Robertson, D.S. and, Carter, W.E., 1982a, “Earth Rotation Information Derived from MERIT and POLARIS VLBI Observations”, in High Precision Earth Rotation and Earth-Moon Dynamics (ed. Calame, O.) pp. 97122, D. Reidel Co., Dordrecht, Holland.Google Scholar
Robertson, D.S. and Carter, W.E., 1982b, “Operation of the National Geodetic Survey POLARIS Network”, in Proceedings of Symposium No. 5: Geodetic Applications of Radio Interferometry, NOAA Technical Report NOS 95 NGS 24, pp. 6370.Google Scholar
Rogers, A.E.E., Knight, C.A., Hinteregger, H.F., Whitney, A.R., Counselman, C.C., Shapiro, I.I., Gourevitch, S.A., and, Clark, T.A., 1978, J. Geophys. Res., 83, pp. 325334.Google Scholar
Shapiro, I.I., Wittels, J. J., Counselman, C. C. III, Robertson, D.S., Whitney, A.R., Hinteregger, H.F., Knight, C.A., Rogers, A.E.E., Clark, T.A., Hutton, L. K., and, Niell, A.E., 1979, Astron. J., 84, pp. 14591469.Google Scholar