We investigate the effects of quasar structure on geodetic 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 (VieVS) 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 percent of the troposphere and clock effects. Our simulations confirm analytical predictions that source structure mitigation strategies must be developed in order to achieve millimetre-level VLBI position accuracy.

Item Type:	Refereed Article
Keywords:	geodesy, Very Long Baseline Interferometry (VLBI), astrometry, Celestial Reference Frame (CRF)
Research Division:	Earth Sciences
Research Group:	Geophysics
Research Field:	Geodesy
Objective Division:	Expanding Knowledge
Objective Group:	Expanding knowledge
Objective Field:	Expanding knowledge in the physical sciences
UTAS Author:	Shabala, SS (Associate Professor Stas Shabala)
UTAS Author:	McCallum, JN (Dr Jamie McCallum)
UTAS Author:	Plank, L (Dr Lucia McCallum)
ID Code:	100257
Year Published:	2015
Funding Support:	Australian Research Council (DE130101399)
Web of Science® Times Cited:	7
Deposited By:	Mathematics and Physics
Deposited On:	2015-05-08
Last Modified:	2017-11-06
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