Inhomogeneous networks and reference frames are an important issue for Very Long Baseline Interferometry (VLBI). In this work we examine the performance of southern stations and baselines in routine VLBI experiments. A positive impact on baseline length repeatabilities of the increased observing effort by the Australian AuScope VLBI antennas is found by analysing three years of global rapid-turnaround VLBI sessions: while worse results are found for southern baselines compared to northern baselines for the first half of the investigated sessions, the northern and southern baseline length repeatabilities are about the same in the second half of the period. In simulations, the actual observing plan with a significantly lower number of observations for southern stations is identified as a major reason for the worse length WRMS for southern baselines, though other factors seem to influence the results as well. Simulating radio source position uncertainties, effects of up to 10 mm are found on baseline length WRMS for long southern baselines. Improving all source position uncertainties through more frequent observations to better than 50 μas could reduce this effect by up to 30%.

Item Type:	Refereed Article
Keywords:	VLBI, southern hemisphere reference frames, source uncertainties, IVS, AuScope
Research Division:	Engineering
Research Group:	Geomatic Engineering
Research Field:	Geodesy
Objective Division:	Expanding Knowledge
Objective Group:	Expanding Knowledge
Objective Field:	Expanding Knowledge in the Physical Sciences
UTAS Author:	Plank, L (Dr Lucia McCallum)
UTAS Author:	Lovell, JEJ (Dr Jim Lovell)
UTAS Author:	Shabala, SS (Dr Stas Shabala)
ID Code:	100258
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:	2017-10-25
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