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The Astrometric Possibilities of Very-Long-Baseline Interferometry

Published online by Cambridge University Press:  04 August 2017

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

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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
Information
Symposium - International Astronomical Union , Volume 109: Astrometric Techniques , 1986 , pp. 143 - 155
Copyright
Copyright © Reidel 1986 

References

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