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GBT Operations & Commissioning Meeting

23 June 2006

AGENDA

• Az Track, Antennae Report -- Bob
• Observing News -- Ron
• Scheduling Status -- Carl
• Microwave Electronics Status -- Roger
  • Operations
  • Development
• Digital Electronics Status -- Randy
• Software Status -- Amy
• Pulsar Related -- Scott
• MIT/LL 43m Project -- Glen
• Any other Business

Az Track, Antennae Report -- Bob

• Jeremy Hill and I continue to work on the tensile testing machine. The controls successfully passed the "smoke test".
• Continental is making progress. They have ordered a big CNC machine, and are making site preparations for it.

Observing News -- Ron

Lost time this week was 6 minutes when the LO1 had a GPiB? write failure. We also had a few no-lost-time problems of:

• GFM failing to update LPC's (3 incidents)
• Astrid lockup
• Winds
• Az Transducer

Eight operator shifts had no problems and five only had no-lost-time problems.

We supported 14 projects in 23 observing sessions, including 2 VLBI runs. Average setup time was the same-old 12 min. The telescope was also scheduled for 42 hrs of mainetence, 8 hrs of software tests, 10 hrs of calibration, and 4.5 hrs of software tests.

Scheduling Status -- Carl

Microwave Electronics Status -- Roger

Operations

No operational issues this week.

Development

High Frequency Receivers: We continue to test the Q-band receiver with the Lab Spectrometer. It is too early to draw firm conclusions, but it appears that with waveguide loads directly on the cryo HFET input flanges, the short-period baseline ripples are missing. If this finding stands up, it is significant and other tests are underway to confirm.

The Ka-band receiver will be tested with the CCB over the next few days. Work on installation of the zpectrometer taps is due to start next week. A spec for changes to the receiver manager is nearing completion.

Other: The buffered power dividers have now been tested in both Converter Racks, and the 60MHz ripple is greatly reduced. (The new units are in OR4 and OR8.) So, construction and installation of the remaining units will proceed.

Digital Electronics Status -- Randy

***Operations, Problem Summary***

Last week's minor problem with the spectrometer in which a self test generated an error message which could not be cleared resulted in Rich Lacasse submitting an MR to AmyShelton? requesting that the cause(s) for the persistence of the error messages be found and eliminated. Since Rich has now officially left the building, I'll be following up on this with Amy.

Summer maintenance continued with lots of work being done on the active surface, including replacement of four LVDT's, two motors, and one cable connector. In addition, the installation of a new fiber cable from Weather 2 to the Pintle Room was coordinated.

***Development***

Cal-Tech Continuum Backend (CCB):

The 2nd CCB is now working properly; having undergone further, more exhaustive testing. It now awaits re-assembly which is expected to be complete by the end of next week.

Mark Clark's CCB "SELF TEST" feature was fully tested, worked flawlessly (good job, Mark!), and has passed its sponsor testing with flying colors.

Lab Spectrometer

The Lab Spectrometer appears to have some remaining issues which result in 100MHz comb artifacts appearing in the spectra along with occasional ACF spikes and resultant ringing. Roger seems to think it's a manageable and stable situation, so we'll most likely wait until John Ford returns after the 4th of July to tackle this issue.

ALMA

John Ford's summer student, Manasseh Obi, began work on a detailed, predictive noise analysis of the bias board with help and input from Randy, Jason, and John.

***Plans***

- Continue CCB construction...
- Evaluate Tektronix scope...
- Continue Active Surface maintenance...
- Continue ALMA support as needed...

Randy

Software Status -- Amy

This ends Week 6 of 6 in the fourth development cycle of 2006 which can be viewed at PlanOfRecordC42006. Integration testing was successfully conducted this week; See the report for the first integration testing session and the report for the second integration testing session for details. Regression tests are scheduled for Sunday, June 25. We plan to release M&C v6.4 on Wednesday, June 28. Release notes for M&C v6.4 are available in draft form. We will also be releasing a patch to GBTIDL. We are calling it version 2.0.1. Release notes for GBTIDL v2.0.1 are available in draft form.

Operational support relatively light for this week and included:

• config_tool user support - A user expected a different Spectrometer configuration then the one config_tool gave. It turned out that the configuration was correct but the supporting documentation need to be updated.
• Reservation System:
  • The alpha reservation directory was completely removed from Charlottesvilles new web directory during the web rearrangement this week.
  • The alpha reservation did not work on the Charlottesville server (php version difference between GB and Charlottesville). We put in a fix but it is not as user friendly because of security issues. We are currently refactactoring the code in order to address these security issues.
• SDFITS user support - Assisted user with problems on an old data set.

We spent a lot of time this week reviewing and interviewing candidates for our open software position. Because the wiki is public, I will include no further details in this report but I will be happy to give an update at the meeting.

Summary of Cycle 4 MRs:

• MRs ready for regression testing:
  • Add LST Capabilities to Scheduling Blocks (ModificationRequest14C306) (CCC approved)
  • Implement CCB Self-Test (ModificationRequest10C306) (CCC approved)
• MRs with sponsor approval:
  • Create Linux Quadrant Detector Manager (ModificationRequest9C306)(CCC approved)
    • This will not be released this cycle. Work is almost complete. However, we will need to allocate some of Ray's time next cycle to finish. Currently, the Manager compiles and links, with new GDAQ library. We still need to add more parameters and samplers having to do with the DT-50 (heater/defroster). Summary of work remaining: DT-50 library, finish DDL, testing.
  • Allow Saving of Invalid Scheduling Blocks (ModificationRequest4C805)(CCC approved)
    • Because the LST MR (mentioned above) took longer than expected. The work associated with this MR will not be released this cycle.
  • Software Fix for Spectrometer "Bad Lags" (ModificationRequest15C306) (Pending CCC approval)
  • Balancing Project:
    • Get, Set, and Change Attenuators (ModificationRequest8C505)
    • IF Rack: Change messages to indicate non-balance and non-linearity (ModificationRequest10C505)
• MRs being written:
  • Integrate F. Schwab's Antenna Trajectory Algorithm & Test (ModificationRequest2C306)
  • Create Penn Array Manager (ModificationRequest3C406)
  • Balancing Project:
    • Converter Rack: Add Ability to Set Power Levels and to Balance to those Levels (ModificationRequest4C505)
    • Change Spectrometer Warning Messages During Balance (ModificationRequest9C505)
    • Multiple sampling for Balancing procedures to diminish RFI effects (ModificationRequest11C505)

Pulsar Related -- Scott

MIT/LL 43m Project -- Glen

MIT/LL is upgrading their electronics this week. Earliest spacecraft tracking will be June 29.

Any other Business

-- RonMaddalena - 22 Jun 2006