EVN TOG-meeting, Onsala Space Observatory, 09:00 Thursday 28th June 2012


  1. Local Arrangements/Opening Remarks (Lindqvist)
  2. Approval & last minute additions to Agenda (all)
  3. Acceptance of minutes from last meeting (all) Arecibo, August 30, 2011
  4. Review of Action Items from last meeting (all; see appended list)
  5. Reliability/Performance of the EVN
    • Pre-session checks, e.g., sampler stats, phase-cal, RFI … (Yang)
    • Extending “near-realtime” fringe checks, status (Yang)
    • NME results (Yang)
    • Feedback from last sessions (Yang)
    • Timeliness of disk shipments (Tenkink / Leeuwinga)
  6. Amplitude Calibration
  7. Digital BBC-systems (DBBC, R1002, CDAS)
  8. JIVE
  9. 2-4 Gbps observations EVN, EVN+VLBA
    • Tests with DBBCs at 2-4 Gbps (Szomoru, Verkouter, Bach, Lindqvist, Tuccari)
    • EVN stations without DBBC: how will 2-4 Gbps be done? (all)
    • Boundary conditions for co-observing with the VLBA at 2 Gbps (all)
  10. Haystack
  11. Mark 5
    • Planning upgrade to SDK 9 and large disks (all)
    • EVN Mark 5A program: feedback d-VLBI/e-VLBI, could it be used for disk-recording? (all)
    • Mark 5 problems encountered during last session, e.g., large disks (all)
    • Disk inventory and purchase status – 7000 € per station/year (Lindqvist, all)
    • Disk throughput at JIVE, balancing with NRAO, Astro/Geo pool (Campbell)
    • Mark 5 logistics (repairs, shipping rules, VLBA shipping requirements, boxes, labels, etc.) (all), Disk repair statistics (Leeuwinga)
    • Contact person concerning disks in the EVN (Lindqvist)
  12. NRAO
  13. Sched Developments
    • DBBC, RDBE, Mark5C etc. (Campbell)
    • New wide-band frequency standards, RDBE and DBBC, (Campbell)
    • DBBC IF-channel naming convention in Sched (Campbell)
  14. Field System, status and new features
  15. Technical priorites for the EVN
  16. Activities at EVN stations (all)
  17. Activities at potential new EVN stations
  18. RadioNet3 (Lindqvist)
  19. Date and place of the next TOG meeting
    • Bonn, March-April 2013
  20. AOB

Action Items from the Arecibo meeting:

  1. Small (JIVE) and Walker to incorporate information on frequency agility in SCHED.
  2. Szomoru to investigate if/how the number of ftp-tests could be increased, as a high time priority of the NEXPReS project.
  3. Contact details for ToO observations should be put on ToO webpage. This is missing for Arecibo, Wetzell - please forward info to Campbell.
  4. Lindqvist to schedule a telecon between the EVN and VLBA to clarify interoperability issues when need arises.
  5. Lindqvist would like a summary/overview from JIVE of what stations get better or worse after calibration.
  6. Dave Graham to send info about the Mark 5B 1pps issue. (Checking offset between input 1pps and output to confirm it is clean.)
  7. All stations getting DBBCs need to make plans for implementing continuous calibration.
  8. Romney to provide details of VLBA experience with continuous calibration
  9. Software from Eb (dbbcn) to be put on TOG wiki, together with pointers to Hobart DBBC wiki.
  10. All stations should add their information relevant for 2/4 Gbps operation to https://deki.mpifrbonn.mpg.de/Working_Groups/EVN_TOG/Frequency_ranges_for_4_Gbps
  11. Romney to ask Brisken to produce a document about tunability and inter-operatability with VLBA. (RDBE with DBBC).
  12. Lindqvist will raise issue of Kvasar stations buying a suitable amount of diskpacks at CBD.
  13. Romney to put Himwich in contact with NRAO programmers (for RDBE control in FS).
  14. All aspiring stations must attend TOW/TOG mini-workshops first, before we would support them in terms of visits to stations.
  15. Next TOG mini-workshop should include a “How to check out a VLBI station.”
  16. The TOG agrees that normal EVN disk pool should not be used for Radioastron observing - forward to CBD about additional disks required.
  17. Directors agreed each institute to invest ~3000 € in spare parts. Stations to define required items on TOG wiki, purchase (coordinated through Alef) and keep on-site as a hot spare which can be sent to other stations as needed.

Summary of ”Permanent” Actions/TOG recommendations


  • Stations should ensure SCHED catalogue information is up-to-date.
  • Stations should update the page of the disk inventory. (Contact Alef to gain access.) They should also indicate the disk space on new modules by e-mail to Alef.


  • Gunn to send email before each session when the final versions of all schedules are ready for download.
  • All should check that Mk5 modules are placed squarely on a flat surface when received; otherwise connectors are easily damaged when bent 8packs get inserted in Mark 5 units.
  • All stations should condition disk packs if time permits, especially those which are to be used for 1 Gbps recording. If a disk pack is found to be not suitable for 1Gbps recording, the label can be changed to 512 Mbps.
  • All stations which do both astronomy and geodesy should clearly distinguish between astronomical and geodetic 8 packs and ensure there is no ”leakage” into the wrong pool, as mixing pools can create problems for scheduling.
  • Disk packs should be shipped with one European and one US address on covers so they can be easily returned in case a shipment is lost in transit.


  • All stations should look at data regularly with chchk program, use it to locate significant RFI, report the results to Polatidis and CRAF representatives and enter them into the database, and use it to check phasecal throughout the session. The chchk program can be run in gaps, or for example on ftp data files.
  • All stations should monitor Tcal throughout sessions. This can be done by running ANTABFS and plotting the results.
  • All stations should forward FS error log files to Himwich in the event of a crash, including details of what the FS was doing when the crash occurred.
  • All stations should try to run the FS diagnostic tests and investigate the results.
  • All stations should ship disk packs as soon as they are full, at least once per week, following the Bologna Rules.


  • All stations should look at pipeline results available from the EVN data archive pages at JIVE, in particular amplitude corrections found by selfcal on strong, compact calibrators. JIVE support scientists should include a comment on the quality of amplitude calibration results, especially to indicate cases where a problem may have occurred and the amplitude correction factors are unreliable.
  • NME calibration files should be made available as early as possible. All stations should look at NME reports sent by JIVE. NMEs should be pipelined as early as possible and email sent to EVNtech when the results are available, to ensure feedback is provided well in advance of the next session.
  • Stations must aim to produce ANTAB and RXG files within 2 weeks after the end of a session. For eVLBI, RXG files from the previous session can often be used. ANTAB files for eVLBI experiments should be produced as soon as possible as rapid analysis is often a high priority for these experiments. JIVE should inform Alef of any problems, so that Directors can be asked to prioritise calibration if insufficient time is available at stations