Journal of Geodesy

, Volume 89, Issue 9, pp 873–886 | Cite as

Simulating the effects of quasar structure on parameters from geodetic VLBI

  • Stanislav S. Shabala
  • Jamie N. McCallum
  • Lucia Plank
  • Johannes Böhm
Original Article


We investigate the effects of quasar structure on geodetic very long baseline interferometry (VLBI) measurements. We create catalogues of simulated and real quasars with a range of structure indices, and use these to generate synthetic CONT11 observations with the Vienna VLBI Software simulator tool. We systematically investigate the effects of quasars with different amounts of source structure, and find that source structure can affect station positions at the one-millimetre level. This effect is stronger for isolated stations. Overall, source structure is found to contribute to about 10 % of the troposphere and clock effects. Our simulations confirm analytical predictions that source structure mitigation strategies must be developed in order to achieve millimetre-level VLBI position accuracy.


Geodesy Very long baseline interferometry (VLBI) Astrometry Celestial reference frame (CRF) 



We thank the anonymous referees for their useful and constructive comments. S. S., J. M. and L. P. thank the Australian Research Council for Research Fellowships. We are grateful to Jim Lovell, Simon Ellingsen, John Dickey and Rob Schaap for useful discussions.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  • Stanislav S. Shabala
    • 1
  • Jamie N. McCallum
    • 1
  • Lucia Plank
    • 1
  • Johannes Böhm
    • 2
  1. 1.School of Physical SciencesUniversity of TasmaniaHobartAustralia
  2. 2.Department of Geodesy and GeoinformationVienna University of TechnologyViennaAustria

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