NEWS

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.

• Benefits for the terrestrial reference frame with VLBI observations to Genesis (Johannes Böhm et al.)
• Atmospheric excitation of the annual wobble over the 21^st-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!

• Geodetic analysis of K band VLBI observations until 2024.0 (Hana Krásná et al.)
• Q band (43 GHz) celestial reference frame observed in 2021 (Hana Krásná et al.)
• Ambiguity Resolution in Legacy Sessions using Singleband Delays (Axel Nothnagel et al.)
• Optimal requirements for determining frame ties using VLBI observations to satellites (Wolf and Böhm)
• VieRDS for Simulating Source Structures at the Raw Data Level (Jakob Gruber et al.)
• Status Report and Aspirations: The Vienna Correlator in the VGOS Era (Jakob Gruber et al.)

The Vienna VLBI group also contributed to several other studies. For more information check out the program and the abstract book.

Jakob attended the “15th DiFX Users and Developers Meeting” in Socorro, New Mexico, USA, from September 11 to 15, 2023. This annual meeting is for the future planning, improvement, and documentation of the high-performance DiFX software. The Vienna Correlation Center uses DiFX in its operational and scientific work to process (correlate) raw VLBI data. The meeting was hosted by the National Radio Astronomy Observatory (NRAO). It was attended by more than 30 participants in person and many more online from 19 different international scientific institutes and agencies. Jakob gave a 30-minute talk on VGOS correlation at the Vienna Scientific Cluster and simulations of VLBI raw data. Some highlights of the many great talks were from H. Rottmann on energy efficient processing using SLURM at the Max-Plank-Institut für Radioastronomie in Bonn, from W. Brisken on the new developments of the DiFX simulation tool of VLBI raw data, from H. Ueshiba on automated correlation at the Tsukuba correlator, from J. Skeens on a combined interferometer approach of VLBI and GNSS data, and from A. Deller on the use of GPUs for VLBI correlation. In addition to the presentations, there were panel discussions on relevant topics such as the switch to GIT for version management of DiFX code.

We at Vienna Correlation Center are pleased to host the next DiFX Meeting 2024 in Vienna and look forward to many great presentations, interesting panel discussions, and a productive DiFX hackathon.

Picture: NRAO

• Earth orientation parameters estimated from recent Australian mixed-mode and Southern Intensive sessions (Sigrid Böhm et al.)
• The benefits of the Australian mixed-mode program (2018 -2023) for the celestial reference frame at S/X-band (Hana Krásná et al.)
• Neglected issues of terrestrial datum definition in VLBI (Lisa Kern et al.)
• Cross-polarization bandpasses of VGOS antennas (Frédéric Jaron et al.)
• Absolute orientation of Galileo orbits from simulated VLBI and GNSS observations (Helene Wolf et al.)

The book of abstracts can be found here.