Date: June 11, 2020

Time: 11:00 am Mountain, 1:00 pm Eastern
Phone: 434-817-6468 ext 228111# (not working, using Walter's Zoom instead)


NRAO: Walter, Jim, Justin, Mark C
USNO: Megan, Nicole, Matt, Chris, Lucas, Andy, Dave
  • VLBA Observations
    • Daily Observation Report (N-series)
      • Three reobservations in May; two probably triggered by bad RFI at PT, one due to software problems at both stations.
      • The N-series isn't getting as good data quality as the F-series so maybe change the setups? If change N also change O. The new P-series has been using the F-series setups on the HN-MK baseline.
      • S-band filters will probably be pulled off of receivers in the near future, might affect quality - this would not apply to PT and MK because they don't have S-band filters.
    • Other Intensive Observations
      • "Holiday" intensive observations at MK
        • Will be substituting MK for Kokee on federal holidays in 2020 such as 7/3/20.
        • Project code for these observations will be IYYDOY.
      • New P-series intensive observations roughly every other day on the HN-MK baseline
        • Project code for these observations will be PYYDOY.
        • Started late on 5/14 instead of the beginning of May due to some confusion about who would be making the files.
        • Using the F-series setups rather than the ones used by the N and O series but duration is 1.5 hours like the N and O series rather than the 1 hour of the F series.
        • Losing some this week due to internet outaget to HN.
      • A MK-WZ observation series ran on Saturdays beginning December 7, 2019 through Feb 22, 2020.
        • Project code for this observation will be QYYDOY.
        • Involves a new post-observing procedure for operators to copy the data to correlator in Japan. This was retested in early June and is working after a configuration change was undone on the correlator side (blocked access).
        • Might restart towards end of calendar year (possibly - awaiting approval.)
        • Being briefly restarted in late June and early July due to the Ishioka station being unavailable.
          • Dates are 6/20, 6/21, 6/27, 6/28, 7/4, 7/5, 7/11, 7/12.
      • O-series test of HN-OV baseline continues
        • Will run simultaneous with the N-series observations but will not interrupt other observing.
        • Possibly expand to include another baseline like SC-BR or SC-LA (avoiding S-band RFI at BR.)
        • Possible oscillation/tracking issue at HN recently detected, suspect an elevation encoder issue.
          • Only seen at low temperatures, hasn't been noticed since January.
    • Post-Monthly Report Review:
      • No backlog from April that needed to be caught up in May.
      • Sowders replacement observation used a little bit over its requested 8 hours in May.
      • A new observation of similar type (but 6cm instead of 13cm) had requested 16 hours a month since April but has used none of it.
      • Project ud009u was run instead of ud009v from the May request, no files were sent by PI in April so the epoch codes are off by one.
        • PI thought files had been provided in six-month batches so doesn't know why there wasn't one for April.
    • Pre-monthly request
      • July request looks fairly standard.
      • A question came up in our internal review, we've been told by David Gordon that his ug003 project finished with ug003x in May but it has continued to be listed in the June and July requests.
  • Open issues
    • USNO emails to ut1 list are not being forwarded along to other USNO people.
      • Mail is being blocked at the Dept. of Defense level, working with them on that.
      • New email addresses for all USNO people was tried. Not fixing the issue. More efforts to investigate it underway.
      • A possible fix is being tested.
    • HN-OV baseline is more precise than any of the others USNO has data for, not sure why. Plus with all the recent problems showing up at PT maybe when fiber available to HN switch the N-series to them and PT-MK to the O-series?
      • HN fiber probably won't be in place until August or September, the work was expected to begin in May but hasn't yet.
        • HN fiber speed expected to be 2.5 Gbps.
    • LA fiber may be at 10 Gbps when it's installed; this might impact consideration towards future use of it in baselines.
      • On schedule for deployment in late July.
    • BR was added to the F-series for testing of additional baselines. S-band RFI might be a problem though, similar to what PT was recently experiencing but worse. Mitigation work on BR's S-band RFI probably won't happen any time soon given current situation.
      • Several of the F-series runs with BR have been correlated. Initial checks last month it looked like only one S-band channel had to be dropped so the RFI may not be that bad with the F-series setups (which are different from the N-series setups).
      • BR looks pretty good.
    • USNO needs to renew support contract for MK fiber.
      • This contract is being moved into the larger support contract (see below), will need to coordinate on handoff.
    • Networking Support Contract: Contract will be renewed.
      • Working on renewal, might involving changing some dates on it to avoid bunching all USNO contracts up at the same time of year. VLBA might all be bundled together at a different date. Moving forward.
    • Correlator Refresh Contract
      • Lustre filesystem and second set of nodes still awaiting installation.
      • The new "BeeGFS" file system has been assembled and configured and is being tested in Socorro.
      • The second set of nodes cannot be installed until USNO is off of their old correlator first, waiting for confirmation from USNO that they have done so.
        • Have started parallel testing of old and new correlator. Seeing some differences, tracking down what might be causing them.
      • Install likely on hold due to COVID-19 work and travel restrictions, though a remote installation is a possibility.
        • The old Lustre filesystem can't be updated and is viewed as a security concern so there's pressure to get this done.
      • Extension through 11/30 for the hardware refresh has been approved.

    • A follow-on to the correlator support contract is being worked on. Walter will coordinate with USNO for NRAO's side. Has been resubmitted and is moving forward.

    • USNO is moving to new ingest data server and IP address is not working even though it's on NRAO's whitelist. USNO reports attempts to transfer data to the .179 address does not work. Looks like problem might be firewalls at USNO end.
      • Waiting on hardware and software updates, ETA end of July.
    • Transition to Mark6 recording system is done, including 4 Gbps capability.
      • Tests for transitioning to the higher data rate, perhaps with C-band, will be considered. (Though C-band has ionosphere problems.)
        • Mark Claussen will provide some 4 Gbps setups for USNO to look at for the tests. Hasn't happened yet.
      • Might be some USNO funding for more Mark6 disk drives/packs. NRAO doesn't currently have a need for more disk packs but that could change in the future once more 4Gbps observing starts. USNO has around 70 Mark6 disk packs not being used, mostly 32 TB. Could be used for RDV data copying at Haystack or for small global runs.
        • Some have gone out to VGOS stations but there's still some available. Maybe spare 10-20?
        • Since they're old, any packs provided should probably be reconditioned before use.
      • Mark5c support will be diminishing and going away for DifX, are there any implications for USNO's correlator usage? Not really. Due to them not being OS upgradable any more they're being air-gapped for security reasons and only being used for copying data to external HDDs.
    • New IVS session code naming structure (long-term issue)
      • There is likely to be a change to format of the IVS "session code", but maybe not until 2021. As the USNO works to make the VLBA intensives look like IVS sessions we want to discuss what impacts such a change might have on this effort. This particularly relates to the 'exper_name' in the .vex files.
      • Intensives are all now using the xYYDOY naming format (ie, N20001, O20001, etc)
      • New IVS codes will be similar to existing codes but perhaps slightly longer, for example "NYYYYDOYNN". USNO & Goddard have discussion about it, length will be more than six characters. NRAO has already used some seven character length codes (such as "N20014B") without it causing any problems.
    • VLBA able to participate in CONT2020 (Nov-Dec 2020). Won't be a full 15-day session, maybe a "mini-CONT" of around five days. (Long-term issue)
      • If this happens will it still be in the November-December timeframe? USNO will check with IVS.
      • Looks like not even a mini-CONT this year.
      • But there's interest in having VLBA observe along with a VGOS session in "mixed-mode". But there's apparently some support problems with latest version of DifX correlator software and VGOS, more technical discussions need to be held to determine what could be done.
    • Peculiar delays (long term issue) - VLBA has a delay compared to Kokee that perhaps should be checked out. Maybe put some VLBA stations into a KK observation as tagalongs so comparisons can be made. Walter reached out to some people, says it looks like it would be a bigger effort than anticipated and may have to wait until things return to normal.
    • Next meeting July 9.

-- JimOgle - 2020-06-09
Topic revision: r2 - 2020-06-11, JimOgle
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