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| Time | Speaker | Topic | Files | Outcome | ||||||
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| 9:15 | Benedikt Soja | Welcome, Introduction |
| The agenda was approved. | ||||||
| 9:20 | Benedikt Soja, Alexander Kehm, Shrishail Raut | ITRF2020-u2025 Update
| see presentation by B. Soja above
| 1) ITRF2020-u2025 (Full Reprocessing): B. Soja provided background information and a status report on the full reprocessing of the whole VLBI history until 2026.0. This effort aims for a new state-of-the-art solution with consistent models and processing strategies. 15 ACs contributed solutions (well appreciated!). For the first time, K-band data is included alongside S/X and VGOS based on 3 ACs contributions (effort by the K-Band working group is well appreciated!). The IVS-CC is currently computing the combined solution, to be finalized and sent to Zuheir Altamimi before EGU and published via data repositories. B. Soja will collect a list of co-authors. 2) Data inconsistency: In the preparation of the reprocessing, significant inconsistencies were identified in the VLBI data archive, which were largely resolved. Still, certain issues remain, such as missing IVS wrappers, as identified by S. Böhm and G. Beyerle. B. Soja will send the relevant information to C. Dieck. R. Haas noted that VLBI data in different data centers are inconsistent.
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| 10:15 | Axel Nothnagel, Sergei Bolotin, Hana Krasna | Ionospheric information in vgosDB files |
| Software fixes for S/X ionospheric information were implemented and applied for sessions since 2022. vgosDB files before 2022 need to be corrected by the corresponding responsible ACs. D. Gordon noted that new corrections have introduced more noise. M.H. Xu noted the issue of weighted effective frequencies causing issues with non-constant ambiguities. The 2026 IVS sessions need to be looked at as soon as all IVS correlators and submitting agencies will have changed to nuSolve-0.8.3. A. Nothnagel will organize a coordinated activity also for the pre-2022.0 sessions. | ||||||
| 10:30 | Coffee break | |||||||||
| 11:00 | Karine le Bail | WG 9 Scale report and discussion |
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| 11:20 | Lucia McCallum | WG 7 Satellite observations report and discussion |
| L. McCallum reported about activities of IVS WG 7 and issues relevant to this group. The message here is that people interested in working with VLBI satellite observations are encouraged to engage with and contribute to WG7. | ||||||
| 11:40 | Lucia McCallum | Inform ACs of the activities of the OPC, e.g., R&D sessions |
| L. McCallum in her role as chair of the OPC reported about the rationale for the IVS observing programme and questions to be answered in preparation for the observing plan 2027. She emphasised that the OPC relies on information provided and investigations performed by all IVS members, and analysts in particular. Please let the OPC know your thoughts and wishes about session cadence and communicate your findings. Specifically, feedback about the performance of the VGOS sessions is appreciated. During the following discussion is became clear that all IVS entities need to improve their communication and active seeking of information across all activities within the IVS. | ||||||
| 12:00 | Lunch break | |||||||||
| 13:00 | Benedikt Soja | Recap of UAW#8 2026 in Munich | see presentation by B. Soja above | Unified Analysis Workshop (UAW) Topics with clear recommendations to IVS ACs: Atmosphere: ACs are encouraged to implement turbulence-based stochastic modeling for tropospheric delays. Automation: ACs are encouraged to explore tools to automate manual bottlenecks in the analysis chain. | ||||||
| 13:30 | Benedikt Soja | Gravitational deformation with azimuth dependency: ANTEX 2.0 format? | see presentation by B. Soja above | A draft of an IVS Resolution encourages gravitational deformation modeling in both elevation and azimuth. ANTEX 2.0 was suggested as a potential file format. | ||||||
| 13:45 | Tobias Nilsson | Effect of non-tidal loading on VLBI analysis |
| ACs are encouraged to apply non-tidal hydrology and ocean loading models. Standardizing the detrending of loading data is an important issue that needs to be further discussed. | ||||||
| 14:00 | Richard Gross | Increase resilience in IVS data analysis and products |
| While scientific users need state-of-the-art data and products from the IAG's Services, reliability is the major need of the growing number of non-scientific users. Since most users, both scientific and non-scientific, use the combined products from the Services, it is suggested that the reliability of the combined products be increased by, for example, establishing additional combination centers. The additional combination centers should be encouraged to determine their combined products using different approaches and to intercompare their results to ensure that they are consistent with each other. | ||||||
| 14:15 | Simone Bernhart | Create a feedback loop between correlators and submitting ACs so that correlators can fix problems | n/a | |||||||
| 14:30 | Coffee break | |||||||||
| 15:00 | Axel Nothnagel | How to handle special station names used for hardware testing? | see presentation by A. Nothnagel above | Correlators introduced purpose-based station names such as NOTOVDIF for correlations of parallel data streams through separate signal chains. These often ended up in operational databases and cause Level-2 analysis programs to stumble. It is almost impossible to eliminate them afterwards and no further activities on existing databases are foreseen. However, a recommendation is given to PIs and correlators handling such data in new sessions that always two vgosDBs are produced, one with and one without purpose-based (non-standard) station names and data. Only the latter one should be submitted to the IVS data centers and the other one transferred to the PI. | ||||||
| 15:15 | Claudia Flohrer | Discuss the latency of 24h sessions for C04 contribution |
| Overview of latencies for R1/R4 and VGOS-OPS/R3 sessions reveals that VGOS-OPS processing is getting faster and could in principle contribute to the combined IVS EOP product. The latency of the first R3 session looks promising. BKG offered to look into ways how to monitor the latencies of the different correlation and analysis centers. Currently the time stamps are not saved and overwritten with any new reprocessing. Other session types, e.g. AUA, might also contribute to C04, but latencies are quite high. BKG encouraged the IVS to look into priorities and bottle necks in order to improve the latencies for other 24h session types, which could contribute to the IVS EOP product used for the C04 generation. | ||||||
| 15:30 | Claudia Flohrer | Clarification on vgosDB documentation | see presentation by C. Flohrer above | Documentation is still labeled draft. BKG encourages the IVS to push for a final version. This is also the chance to take into account complainscomplaints/proposals for improvement. Hana Krasna mentioned inconsistencies. A versioning might be helpful, to keep track of format changes (upcoming for Genesis). It was discussed that an additional keyword indicating VGOS or legacy observations might be useful. Everybody should be aware that units are not defined by the format description. Thus units need to be read as well. This should be emphasized in the format description document. BKG was also asking for a "user handbook" or "operation procedure" containing recommendations on how to use the vgosDB content, dependent on the processing step or session type. The example of the cable delay revealed, that the "CableSign" does not need to be considered by the analysts. The "CableCal" contains already the sign. This clarification could also be added to the documentation. | ||||||
| 15:45 | Claudia Flohrer | Discuss pre-processing chain for vgosDB | see presentation by C. Flohrer above | BKG presents its view of the preprocessing steps and how they affect the content of the vgosDB. It turned out, that nuSolve is needed for ambiguity resolution, also in the case of VGOS observations. BKG received a very good feedback for providing this summary. BKG will approach each IVS AC and collect information on the used vgosDB content. This information could be provided to everybody and it may allow to better understand the product generation, to judge how independent the different AC solutions are and to help "newcomers" to get started. BKG will discuss with the ACo how to provide this information. | ||||||
| 16:00 | Sadegh Modiri | BKG IVS AC status report about activities/news |
| 1- Operational Activities: 2- Automation of Intensive Session Processing: 3- Data Availability: | ||||||
| 16:15 | Rüdiger Haas | How to deal with sub-amgibuities? |
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| 16:30 | Benedikt Soja | Wrap-up, conclusions, group photo |
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