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GBT Operations & Commissioning Meeting

11th August 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

• • We repaired the weld defect found directly under the receiver room on Tuesday. Most of the day Monday was also spent in preparation for this work, as well as safety review. The work went well, thanks to the big effort by David, Ike, and many others.

Observing News -- Ron

We had a busy week with 18 projects in 24 observing sessions including a VLB session and two sessions for the Governor's School. Average setup time was 14 minutes. We also had 41 hrs of maintenance.

of the 14 operator shifts, only 5 had lost-time problems. Lost time was 4.5 hrs, about 3.5% of the time scheduled for observations. The failures were:

• Astrid/GFM/Config-Tool/Scan Coordinator -- 2.1 hrs plus 3 NLT's
• Feed Defroster -- 1.5 hrs
• S-Band Noise Diodes -- 0.3 hrs
• Active Surface -- 0.3 hrs
• Power/Lightning -- 0.3 hrs
• SDFITS -- NLT

The lost time includes the cancellation of a project in order to repair the defroster.

Scheduling Status -- Carl

Last Week
=========

Observations for proposals
   GBT06A-053, GBT06B-052, GBT06B-030,
   GBT06B-020, GBT06A-054, GBT06B-021,
   GBT05C-042, GBT02A-053, BU031     ,
   GBT06A-013, GBT06A-046, GBT06B-012,
   GBT06A-014, GBT06B-013, GBT06A-004,
   GBT05C-046, GBT06B-026

Completed proposals
   GBT06B-052, GBT06B-012

Next Week
=========
Observations scheduled for **
  GBT06B-040 [F  ] Nissim Kanekar
       A Targeted High Frequency Search for Pulsars at
       the Galactic Center
  GBT06B-032 [F  ] Steve Begin
       Timing of the Binary and Millisecond Pulsars in
       M28
  GBT06B-021 [F  ] Karen Masters
       Mapping Matter in the Nearby Universe with 2MASS
  GBT06B-033 [F  ] Jason Hessels
       Completing a 350-MHz Survey of the Galactic Plane
       for Pulsars and Transients
  BK127      [F  ] Kirsten Knudsen
       Resolving the AGN and the starburst in an
       intensely starforming quasar
  GBT02A-053 [F  ] Carl Heiles
       Magnetic fields in Photodissociation regions from
       Zeeman splitting of Carbon Recombination Lines
  GBT06B-034 [F  ] Jacqueline van Gorkom
       Galaxy evolution in groups: HI properties of 80
       2dfGRS-selected groups
  GBT06B-013 [F  ] Tyler Foster
       CTB 102: The Largest HII Region in the Galaxy?
  GBT06B-014 [F  ] Paulo Freire
       Continued timing of the eccentric binary system
       in the globular cluster NGC 1851
  GBT06B-026 [F  ] Julia Deneva
       Searching for Pulsars and Transient Sources in
       the Galactic Center
  GBT06B-028 [F  ] Ingrid Stairs
       Timing the Planet Pulsar in M4
  GBT06A-070 [F  ] Fernando Camilo
       A new radio transient
  GBT06B-009 [F B] Joe Helmboldt
       The Efficiency of the Star Formation Episodes
       That Lead to K+A Galaxies
  GBT06A-072 [F  ] Vicky Kaspi
       ToO GBT Observations of AXP 4U 0142+61
** Scheduled as F-ixed, P-rimary, B-ackup

Contact Information for 08/24/2006 - 09/07/2006
=======================================
Proposal   PI                 Bands Email [NRAO contact]
---------- ------------------ ----- --------------------
GBT06A-054 Paul Demorest      L     demorest@astron.berkeley.edu [Scott Ransom]
BF088      Vincent Fish       L     vfish@nrao.edu []
GBT06B-053 Min Yun            L     myun@astro.umass.edu [Toney Minter]
GBT06B-032 Steve Begin        S     sbegin@physics.ubc.ca [Scott Ransom]
GBT05C-042 Scott Ransom       S     sransom@nrao.edu [Scott Ransom]
GBT06B-011 David Champion     3     champion@physics.mcgill.ca [Scott Ransom]
GBT06B-033 Jason Hessels      3     hessels@physics.mcgill.ca [Scott Ransom]
GBT06A-046 Glen Langston      U     glangsto@nrao.edu [Glen Langston]
GBT06B-034 Jacqueline van Gor L     jvangork@astro.columbia.edu [Frank Ghigo]
GBT06A-014 Andrea Tarchi      K     atarchi@ira.cnr.it [Jim Braatz]
GBT06B-035 Brian Kent         L     bkent@astro.cornell.edu [Frank Ghigo]
GBT06B-024 Jeff Mangum        K     jmangum@nrao.edu [Frank Ghigo]
GBT05C-023 Fernando Camilo    8     fernando@astro.columbia.edu [Scott Ransom]
GBT06B-025 Maura McLaughlin   3     maura.mclaughlin@mail.wvu.edu [Scott Ransom]
GBT05C-046 Ingrid Stairs      L     istairs@astro.ubc.ca [Scott Ransom]
GBT06B-026 Julia Deneva       XC    deneva@astro.cornell.edu [Scott Ransom]
GBT06B-027 Ted Bergin         K     ebergin@umich.edu [Scott Ransom]
GBT04B-014 Paul Kondratko     KU    pkondrat@cfa.harvard.edu [Jim Braatz]
GBT06B-019 Toney Minter       L     tminter@nrao.edu [Toney Minter]
GBT06A-071 Fernando Camilo    L     fernando@astro.columbia.edu [Scott Ransom]

Scheduled hours [backup]
========================
Category/Month-> August    September
    Astronomy ~  420 [044] 459 [282]
  Maintenance ~  199        40 [068]
  Test & Comm ~  121 [003] 157 [021]
  Un-assigned ~    4        64

Proposal Checkouts
==================
Awaiting checkout - 0
  Active checkout - 0
          On Hold - 20
         Schedule - 57
        Completed - 524


Current backlog [hours prior to 06B*] = 1016
   [2001:2(1), 2002:3(1), 2003:19(1), 2004:107(7), 2005:544(23), 2006:341(18)]
   Backlog excluding 139 hrs of monitoring projects after 06B = 877
Total time to discharge [hours] = 3719
   Includes 419 hours of monitoring after trimester 06B
* Includes projects that are on hold for trimester 06B

Microwave Electronics Status -- Roger

Operations

A series of problems were reported last weekend. One S-band noise calibration signal was not working, and the feed defroster failed. The feed defroster problem was blown fuses, and the noise cal was a combination of a failed RF switch and digital logic chips. The problems were corrected, but the S-band cal levels require recalibration. We suspect the problems were related to power line transients.

Development

Q-band Receiver: Work on upgrading the 300K RF plate to bring the bandwidth up to spec continued this week. Grounding and transient protection of the HFET LNA bias circuitry is being improved. Five new amplifiers were obtained from CDL this week. A trip to CDL and discussions with staff there about the spectral instabilities was productive.

Ka Receiver: Assembly of the 300K RF section continues; migration to a new technician on the job is going well. We are about 1.5 weeks behind schedule.

C-band: Finished PCB artwork, sent Gerber files to Hughes for fab. Fixture parts have been gold plated and returned to GB. Assembly and fab are underway. Mixer evealuation completed. Sent eval unit (loan) back to Marki Microwave.

Zpectrometer: Wiring of the rack was completed and it was shipped to UMd.

Digital Electronics Status -- Randy

***Operations, Problem Summary***

Active Surface...

- Jason responded to a callout Sunday to deal with a loss of communications with the Active Surface.
A trip to the Actuator Room to reset the computers and Reset Box cleared the problem.
- Repaired two LVDT modules which re-activated a total of 80 actuators.

Feed Defroster...

During Sunday's callout, Jason also assisted Bob Simon in re-establishing AC power to the Feed Defroster
by replacing two fuses inside the RFI box on the turret.

***Development***

Caltech Continuum Backend (CCB)...

Construction of CCB #3 is still underway with an expected completion date of 18-AUG-06.

Spectrometer LTA Re-design...

Work continues on the LTA re-design project... A detailed project schedule should be ready by 18-AUG-06.
Following this, an informal preliminary design review will be scheduled for sometime in late August or
early September.

Lab Spectrometer...

- A second High Speed Sampler (ALMA #3) was added to the Lab Spectrometer and awaits testing and evaluation
by Roger.
- J.D. began work on the design of a rack-mount 10MHz/1PPS signal generator for use on the Lab Spectrometer.

ALMA (As reported by Jason Ray)...

- Received back and tested a Rev C Module which had undergone "shake testing". Initial tests uncovered
at least one newly compromised connection on one of the circuit boards.
- Placed an order with FreedomCAD? to do a new PC layout to eliminate buried/blind vias.
- Reconciled inventory of parts required to complete Rev C2 shipment and prepared a list of parts to be ordered.
- Worked with Dennis and the Machine Shop to complete parts required for a "mechanical fit test" which should
be carried out sometime next week.
- Manasseh Obi continued his work on bias card noise analyses and measurements with input from Jason.

***Plans***

- Continue Active Surface maintenance...
- Continue construction of CCB #3...
- Continue work on LTA re-design and prepare project schedule...
- Continue work on 10MHz/1PPS signal source for Lab Spectrometer
- Continue ALMA support as needed...

Software Status -- Amy

The entire group was gone for the Software Engineering Conference in Socorro. In general, I think that everyone liked the conference and got something useful from it. GBT personnel made some good connections and ideas for software that will benefit the GBT.

Pulsar Related -- Scott

Spigot usage is starting to pick up again -- and just in time for Prague! The last intense session went well and I'm going to send emails to all the observers for the next 2 weeks requesting "speedy" data backups/processing...

Found the "new" PCS interference in some Spigot observations this week. Hopefully this does not become a common occurrence.

Finally, I started digging into the Spigot C-code with my new student (Ryan Lynch). The goal is to finally get the 8-bit 2048-lag modes working.

MIT/LL 43m Project -- Glen

Any other Business

-- RichardPrestage - 10 Aug 2006