VEGAS Team Meeting

Agenda:

1. OGP calibration; status of ADC calibration in general
2. Usage of MMCM in low bandwidth mode
3. ADC calibration routines and documentation for DIBAS
4. Mode 10-19 (ghost frequencies issue)
5. Blanking of last switched integration
6. Status of “Manager writes to many sub-bands in 8 subband mode” problem (release and test)
7. Content of August 'release'
8. Use of test time (including overnights)
9. Status of other “current issues”: https://safe.nrao.edu/wiki/bin/view/CICADA/CICADAGreenBankSpectrometerCurrentIssues
10. Resource plan for Q4 FY2015

Meeting notes:

1. OGP calibration; status of ADC calibration in general
   • we are basically done
   • the MR has been signed by the sponsor (Jason Ray)
     • Not an effect on August release
2. Usage of MMCM in low bandwidth mode: VEGAS, unfortunately, has some modes which clock the ADC at very low sample rates, which forces us to use low bandwidth mode
   • there is still the issue about this fundamental flaw with the MMCM calibrations occasionally failing: we discussed at the end of the last meeting ways we could get around this, but I haven't heard any more details on it and I don't have any action items to follow through on. Right now our Manager expects that these measurements will occasionally fail.
3. ADC calibration routines and documentation for DIBAS
   • we are putting the finishing touches on the docs intended for DIBAS
4. Mode 10-19 (ghost frequencies issue)
   • Randy looking at bof files
   • Joe on GPU with time series snapshots - working on issue with extraction routine
     • real and ghost spectra are sometimes swapped
   • Anish looking at data from above
5. Blanking of last switched integration
   • Released
6. Status of “Manager writes to many sub-bands in 8 subband mode” problem (release and test)
   • Released
7. Use of test time (including overnights)
   • Unscheduled request(s)
     • none
   • Tuesday
     • 13:00 - 15:00 mixed mode testing and checking vegas exposure time with LO1 switching [Roshi]
   • Wednesday
     • No time yet reserved
   • Thursday
     • 8:00am – 12pm; Streaming Data Display tests [Kepley/Brandt]
8. Status of other “current issues”: https://safe.nrao.edu/wiki/bin/view/CICADA/CICADAGreenBankSpectrometerCurrentIssues

Other

1. Please make sure to properly code your timesheets for the current time period and going forward.
   • Software engineers should be using a GBT ops software CM&E account - Account 893252
   • Electronic engineers should be using a GBT ops electronics CM&E account - Account 432510
   • Commissioning activities should be getting charged to hardware support and testing - Account 432510
   • Scientists assisting with shared-risk commissioning should be charging an observer support account
     • 432540 for the most part. Accounts 142020 (GB-based staff) and 142010 (CV-based staff) for when you are helping with overarching observing support (not problem solving, VEGAS specific)