We determine quarterly solutions of celestial and terrestrial reference frames together with session-wise estimates of Earth Orientation Parameters (EOP). Furthermore, we automatically derive UT1 estimates from IVS Intensive sessions.

In the past, Lucia Plank carried out a comparison campaign of VLBI analysis software packages. Information and results can also be found here.

The Vienna Terrestrial Reference Frames contain positions and velocities assuming linear motion of stations, and the Vienna Celestial Reference Frames list the positions of radio sources. They were estimated simultaneously with session-wise Earth Orientation Parameters (EOP) in a common global adjustment using VLBI observations since 1984. If you use these frames or EOP, please use this reference:

Hana Krásná, Johannes Böhm, Lucia Plank, Tobias Nilsson, Harald Schuh, Atmospheric Effects on VLBI-Derived Terrestrial and Celestial Reference Frames, Earth on the Edge: Science for a Sustainable Planet Proceedings of the IAG General Assembly, Melbourne, Australia, June 28 - July 2, 2011, Series: International Association of Geodesy Symposia, Vol. 139, edited by Chris Rizos and Pascal Willis, pp. 203-208, 2014.

• VieTRF13
• VieTRF13b

• VieCRF13
• VieCRF13b

• VieEOP13
• VieEOP13b

Axis offsets determined with VieVS can be downloaded from here:

• VIE_AO_8413

The figure below shows UT1-UTC for last 30 days estimated using VieVS. This calculation is done automatically and no manual corrections are applied in case of problems.

The Comparison Campaign was started with the goal to compare different VLBI analysis software packages on the basis of the computed delay and its partial derivatives. Here you find detailed information and the corresponding data files. Find instructions to take part in the Information note. In order to learn more about your software and the settings you used for the calculation, please fill out the Analysis Report and send it with your results.

EOP file for the time of observation:

• EOP

NGS-files for DeDeCC1, reduced mode: NGS_reduced

NGS-files for DeDeCC1, full mode: NGS_full

Catalogue file : 2005EXT1.CAT (zipped)

EOP.yy files: EOP

Reduced databases prepared by D. Gordon: Calc_DB

L. Plank, J. Böhm, H. Schuh, Comparison Campaign of VLBI Data Analysis Software - First Results, Proceedings of the IVS General Meeting 2010, Hobart, AUS, 2010

L. Plank, J. Böhm, H. Schuh, DeDeCC - Comparison of VLBI data analysis software - results, presented at the 12th IVS Analysis Workshop, March 31, 2011, Bonn, GER, 2011