NEWS
Vienna VLBI Group at EVGA 2025
- Effective Frequencies And Ionosphere Calibration Of Legacy S/X Data (Axel Nothnagel)
- The VLBI Scale Drift: Current Status And Remaining Challenges (Lisa Kern)
- VGOS CRF: Celestial Reference Frame From The VLBI Global Observing System Until 2024 (Hana Krásná)
- Impact Of Atmospheric Turbulence On VGOS Telescope Location In India (Arnab Laha)
- Hybrid Modelling Of Corrections For Geophysical And Unmodelled Effects In VLBI Data Analysis (Shivangi Singh)
- Mitigating Source Structure On The Visibility Level (Frédéric Jaron)
- Impact Of The Inclination Of Genesis On The VLBI Terrestrial Reference Frame (Helene Wolf)
Selected talks and posters are available here.
Department Seminar at Masaryk University in Brno
On Friday, March 28, 2025, Frederic Jaron was invited as a speaker in the Seminar of the Department of Theoretical Physics and Astrophysics at the Masaryk University in Brno, Czech Republic. The subject of the talk was his research on the gamma-ray emitting binary star LS I +61°303. Frederic also used the opportunity to introduce the topic of geodetic VLBI to the audience, which consisted of both researchers and students.
Paper on Terrestrial Reference Frame Scale Drift Anomalies in VLBI published
An unexpected VLBI scale drift has been observed in the latest realization of the ITRS, ITRF2020, beginning shortly after epoch 2013.75 and continuing through 2021.0. A detailed analysis of the station motion model for NYALES20 (Svalbard, Norway) revealed a linear increase in station height during this period, attributed to present-day ice mass loss, perfectly aligning with the observed VLBI scale drift. The present study investigates the impact of an updated station discontinuity model for NYALES20 on determining the VLBI scale. Check it out!
9th International VLBI Technology Workshop 2024
The 9th International VLBI Technology Workshop was held from October 20 to 23, 2024 at MIT Haystack Observatory, Westford, MA, USA. The scope of this conference was hardware and software development related to VLBI technology. Frederic Jaron contributed three talks on the following topics:
– A Source Structure Correction Tool for VLBI Visibility Data
– Cross-polarization Gain Calibration of VGOS Antennas
– VGOS Phase Cal Performance at High Frequencies
This on-site conference brought together experts from both the astronomical and the geodetic application of VLBI, which led to very fruitful discussions.
TU Wien Joins Global Effort in Geodesy as a Partner of the United Nations Geodetic Centre of Excellence
The UN-GGCE Partnership Program launched in June 2024 to recognize the exceptional commitment and significant contributions Member States, universities, and organizations have made to the science of geodesy and strengthening the global geodesy supply chain. Since July 2024, TU Wien is recognized as a valued “Partner” of the UN-GGCE. This partnership acknowledges TU Wien’s expertise in Earth observations and representation, supporting global efforts in many scientific areas such as sustainable development. By joining this network, TU Wien strengthens its involvement in key international initiatives aimed at improving the precision and accessibility of geospatial data. This partnership marks a major step forward in raising awareness of the importance of geodesy and its role in shaping global geospatial infrastructure. More information can be found at the website of the UN-GGCE.
16th DiFX Users and Developers Meeting 2024
The 16th DiFX Users and Developers Meeting was held in Vienna from September 9 to 13, 2024. The first two days were devoted to the DiFX Users at the Federal Office of Metrology and Surveying (BEV) with many interesting presentations also from our Vienna VLBI group. The last three days were dedicated to the DiFX Developers who met at the TU Wien.
Further details and the photo shown here are both sourced from here.
European VLBI Network Symposium 2024
The 16th European VLBI Network (EVN) Symposium took place in Bonn from September 2nd to 6th, 2024. Frédéric Jaron presented a poster summarizing recent results from a project about the mitigation of source structure in geodetic VLBI.
The conference was an excellent opportunity for the discussion with leading experts in the field.
Excursion to the Geodetic Observatory Wettzell
Paper on Cross-Polarization Gain Calibration of Linearly Polarized VLBI Antennas published
The new-generation geodetic radio telescopes observe two orthogonal linear polarization directions. Calibration of the gain differences between the two polarizers is necessary to maximize the signal-to-noise ratio of observations. This study investigates these cross-polarization gain differences and their temporal evolution for selected antennas. Check it out!
Vienna VLBI Group at EGU 2024
- Benefits for the terrestrial reference frame with VLBI observations to Genesis (Johannes Böhm et al.)
- Atmospheric excitation of the annual wobble over the 21st-century from CMIP6 predictions under different scenarios (Sigrid Böhm et al.)
- Verifying the impact of additional breaks in station coordinates on VLBI scale drift (Lisa Kern et al.)
- Potential of VLBI observations to satellites to estimate orbital elements (Helene Wolf et al.)
Like every year, it was an enriching experience to engage with fellow researchers and exchange insights at this esteemed gathering. We look forward to next year!