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GBT Operations & Commissioning Meeting

26 May 2006

AGENDA

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

Az Track, Antennae Report -- Bob

I'm helping with the prime focus receiver change this morning.

Observing News -- Ron

We supported 16 projects in 29 observing sessions, including a VLB run and observations of the comet. Average setup times was the 'average' 15 minutes. The schedule was almost all astronomy -- only 8.5 hrs went to maintenance and there was no test time of any sort. Lost time was 2.8 hrs, about 1.8% of the time scheduled for astronomy. Of the 14 operator shifts, 4 had no problems at all and 3 had problems that did not cause any lost time. The problems for this week include:

• Computing -- Wind needed rebooting : 1.0 hrs
• Dynamic Corrections Failure : 0.4 hrs
• Winds : 0.4 hrs
• Receiver Room HVAC Failure : 0.4 hrs
• Astrid Hang ups : 0.3 hrs plus 2 during setups
• Spectral Processor, GFM : 0.3 hrs
• Titania lockup : during setups
• VNC user confusion : during setups

It's not clear from the operator logs as to why it took so long to determine that Wind needed rebooting. The resolution of the Dynamic Corrections problem was not described.

Scheduling Status -- Carl

Microwave Electronics Status -- Roger

Operations:

No problems reported. The C-band is being cooled down - observations resume in early June.

Development:

The Ka receiver is now in the lab, and tests continue with both the Lab Spectrometer and the CCB. It is too early to come to any conclusions.

The Q-band test dewar is cold, and tests of the receiver chain are beginning. We have not yet used the Lab Spectrometer on it.

Two of the "buffered" power dividers are now in the Converter Racks (ORM 4 and 8). System tests are TBD.

Digital Electronics Status -- Rich

***Operations, Problem summary***

There are no significant digital hardware problems to report this week.

***Development***

Cal-Tech Continuum Backend (CCB):

Lots of progress has been made this week toward completion of the 2nd CCB (now 90% complete). We still expect to have the unit fully assembled and ready for testing by 31-MAY-06...

Lab Spectrometer

- The spectrometer was successfully used to acquired receiver data this week. There were a few growing pains, but, with some help from the SDD, we muddled through.
- A 3 GHz oscilloscope was received from LeCroy? this week. We have been using it to investigate timing problems in one of the samplers. The scope is pretty nice – it’s amazing what you can get for only 40 grand. So far everything we’ve looked at looks normal.

***Plans***

- Continue CCB construction...
- Continue Lab Spectrometer commissioning…
- Continue ALMA support as needed...

Randy and Rich

Software Status -- Amy

This ends Week 2 of 6 in the fourth development cycle of 2006 which can be viewed at PlanOfRecordC42006.

Operational support for this week included:

• Electronics Lab software installation support - updated version to 6.3 and Lab Spectrometer support
• Astrid frozen screens
• Astrid scheduling blocks were failing because of retention of bad source velocity arrays from the previous block, fixed for next release
• Ygor devices were generating a bad time string for FITS files because of rounding error, we have a tentative solution awaiting testing.
• Investigation into Antenna reporting a message concerning the dynamic focus corrections.
• Online Sdfits restart
• User support - Found and corrected cause of infinite loop in Astrid simulation.

Summary of Cycle 4 MRs:

• MRs with sponsor approval:
  • Create Linux Quadrant Detector Manager (ModificationRequest9C306)
  • Allow Saving of Invalid Scheduling Blocks (ModificationRequest4C805)
  • Add LST Capabilities to Scheduling Blocks (ModificationRequest14C306)
• MRs awaiting sponsor approval:
  • Implement CCB Self-Test (ModificationRequest10C306)
• MRs being written:
  • Integrate F. Schwab's Antenna Trajectory Algorithm & Test (ModificationRequest2C306)
  • Create Penn Array Manager (ModificationRequest3C406)
  • Balancing Project:
    1. Get, Set, and Change Attenuators (ModificationRequest8C505)
    2. Converter Rack: Add Ability to Set Power Levels and to Balance to those Levels (ModificationRequest4C505)
    3. Change Spectrometer Warning Messages During Balance (ModificationRequest9C505)
    4. IF Rack: Change messages to indicate non-balance and non-linearity (ModificationRequest10C505)
    5. Multiple sampling for Balancing procedures to diminish RFI effects (ModificationRequest11C505)

Pulsar Related -- Scott

Not much to report except that I've been quite involved with helping several groups get new projects setup in astrid (which has seemingly uncovered a new PF1 configuration issue with the Spigot that wasn't there a month ago -- and will be important for Dunc/Maura's observations later today) as well as with helping a couple groups process their spigot data recently. The lack of good Spigot documentation has been moderately annoying (since I always help people set up the astrid blocks anyways), but the last of PRESTO documentation demands a lot more of my time as the Spigot (and PRESTO in general) becomes more widely used!

Also, Spigot usage in general over the next several weeks is going to be incredibly high. There will be lots of requests for the computer folks for mounting and unmounting disks etc...

BTW: I need to leave the meeting early since it is "graduation" day from pre-school today for my daughter...

MIT/LL 43m Project -- Glen

Normal spacecraft tracking. No tracking Monday May 29. Maintenance Tuesday May 30.

Any other Business

-- RonMaddalena - 25 May 2006