MINUTES in bold

CASA/JIVE VLBI Coordination Meeting

2019 January 16 @ 1500UTC

Attendance: George, Mark, Des, Ryan, Neal, Walter


  • NRAO Shutdown status
    • Probably ok through most of February
    • Update (2019Jan17):
      • Basic NRAO operations (with some restrictions on procurement, travel after Feb 1, etc.) now funded through 2019 Feb ~20
      • Atlassian servers (jira, bit-bucket, bamboo, confluence) have been identified as essential infrastructure for international colleagues in general, and will be maintained during any actual shutdown
  • Future Meeting dates (usually last Wed of the month):
    • Next meeting: 2019 Feb 20 @ 1500UTC. Pending MK availability and NRAO shutdown status (MK is available).
    • 2019 Mar 27 @ *1400*UTC (Daylight savings begins 2019 Mar 10 in USA, 2019 Mar 31 in JIVE)
    • 2019 Apr 24
    • 2019 May 29
    • 2019 Jun 26?
    • 2019 Jul 31?

General Admin

  • Important upcoming CASA 5.5 dates
    • Bug fixes / Validation complete: 2019 Jan 31
    • Release: 2019 Feb 18
    • CASA 6 (release: 2019 Apr 19): migrate task/tool interfaces to assure same scientific support as CASA 5.5
  • CASA 5.6/6.1 dates pending (requirements due by ~end of January)
    • Likely: Feature freeze: 2019 Jun 01, Release: 2019 Jul 17
    • CASA 5.6 Confluence page (placeholder, will be populated in coming weeks, try JIRA login to access)
  • Resources from "ESCAPE" for CASA-VLBI development
    • New EU-funded project for scientific infrastructure (incl. CERN, SKA, etc.), with emphasis on cloud computing (Jupyter NB)
    • Will support Des's VLBI development contributions, alongside RINGS
  • Merge of JIVE Workshop Issues List with older NRAO VLBI Req doc
    • (NB: Ilse on leave, currently...)
    • Urgency vis-a-vis CASA 5.6...
    • Mark now to take first stab at collation of requirements,
      • First glance indicates many seem already satisfied (these items to be maintained as complete in the ultimate document)
      • Will identify items appropriate for consideration for 5.6 asap (Feb 1)


  • Status of testing and merges for 5.5
    • In good shape with expected refant-related (faulty merge corrected), convergence criterion, and digital correction items
    • Pull request hiccup? (Des) CAS-12180 (refant list), pull request pending.
  • New flagging-related bug (Des)
    • CAS-12192, bug specific to fringe-fit solutions, but related to polarization-dependent flagging (CAS-695)
  • CAS-9965: UVFITs export documentation: GC, TY exporte not yet supported?
    • Confirmed, but thought not urgent to introduce this support, since these relate to early calibration steps now possible in CASA


  • "perscan" interpolation options (Mark)
    • Relevant when linear interpolation over-flags data due to flagged solutions in isolated scans.
    • Adds a dimension to the calibration "patch panel" mechanism within the calibration apply infrastructure, rather like existing 'perobs' constraint. Has been previously discussed, but this granularity not thought important until now.
    • George to investigate prospects further, likely only in callibrary infrastructure
  • RINGS-related issues (Mark)
    • Extremely wide bandwidth support, including not-fully sampled
    • Dispersive delay solutions
  • Items to push for CASA 5.6/6.1 development
    • (George) Look into correlation-dependent flagging issue (CAS-695)
      • Keen to abandon "workshop branch" (CAS-10684) when this (and user control of convergence iteration) disposed of
    • (Mark/Des) Any residuals from 5.5 work (rereferencing, convergence criterion, alternate refant, digital corrections)?
      • No.
    • (Walter) Advanced VLBA Amplitude calibration a la Walter memo from a few years ago
      • Bandpass normalization flexibility: voltage vs. power
      • accor solutions applied to ACs? (should already be true, else a bug)
    • (Des) Baseline stacking
    • (Des) Wide bandwidth and dispersive (see above)
    • (George) perscan interpolation option (see above)
    • (Mark) Some items may emerge from Mark's requirements collation process.


  • Verification testing: Mark asks for template or examples
    • Neal will provide link to existing tests in the CASA 6 repository (where verification test focus lies)
    • Neal's Link
  • CASA User Committee encourages "investing in making CASA fully VLBI-capable and securing resources to maintain this capability for the longer term" in the context of the VLBA's return to NRAO management and SRDP.
    • This recommendation occurs in "External Contributions" section; probably is designed to prompt a more direct resource commitment from NRAO.
    • Ryan to circulate draft response
Topic revision: r3 - 2019-01-22, MarkKettenis
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