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GBT Operations & Commissioning Meeting

31 March 2006

AGENDA

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

Az Track, Antennae Report -- Bob

• • We received approval from the NSF late Friday to award all of the major contracts. Carol and Mike and I are in the process of doing that now.
  • We will have a presentation from a grout supply company Wednesday.

Observing News -- Ron

Another excellent week of observing. We supported 17 projects in 22 observing sessions, including 2 VLB experiments. Average set up time was under 11 minutes -- the setup time for two sessions was misreported. The telescope was also scheduled for 19 hrs of software tests, 12.5 hrs of maintenance, and 7 hrs of PTCS tests.

Lost time was 2.7 hrs, less than 2% of the time scheduled for astronomy or PTCS tests.

• Subreflector control during PTCS tests : 1.0 hrs
• Astrid (4 instances) : 0.7 hrs
• Spectral Processor (3 instances) : 0.5 hrs
• Water/Snow on radome : 0.3 hrs
• Spectrometer (2 instances) : 0.3 hrs

The operators also reported that observers will frequently lose control of their Astrid session. For one observer, it happened 5 times in 5 hours. The operators weren't reporting these problems in their logs since observing would continue. The steps the observers/operators perform to 'fix' the problem are: observer goes offline, operator takes control and then goes offline, observer takes control, operators select "online monitor only". The frequency at which this problem occurs suggests that observers might be finding this annoying and we might want to look into it.

Scheduling Status -- Carl

Last Week
=========

Observations for proposals
   GBT06A-053, GBT06A-032, GBT06A-011, 
   GBT06A-066, GBT06A-068, GBT05C-065, 
   GBT06A-046, GBT05B-034, GBT06A-027, 
   GBT06A-038, GBT06A-049, BB184     , 
   GBT06A-018, GBT04A-038, GBT06A-009, 
   BH139     

Completed proposals
   BB184, BH139

Next Week
=========
Observations scheduled for **
  GBT06A-053 [  B] Scott Ransom
       Continued Timing of the Binary and Millisecond    
       Pulsars in Terzan 5                               
  GBT06A-044 [  B] Jeremy Darling
       Intrinsic HI and OH Absorption in Compact Radio   
       Sources at High Redshift                          
  GBT06A-011 [F B] Mike Blanton
       HI Content and Dynamics of Dwarf Disk Galaxies    
  GBT06A-066 [F  ] David Nidever
       HI Mapping of the Extended Magellanic Stream      
  GBT06A-046 [ PB] Glen Langston
       A search for the Largest Interstellar Molecule,   
       HC_13N                                            
  GBT05C-032 [ P ] Yancy Shirley
       Tracing Protostellar Mass During Star Formation   
       with 7mm and 9mm Continuum                        
  GBT06A-003 [  B] Chris Clemens
       Observational Tests for Non-radial Oscillations   
       in Radio Pulsars                                  
  GBT06A-059 [ P ] Nissim Kanekar
       Using CCH lines to measure changes in fundamental 
       constants                                         
  GBT06A-049 [ P ] Tony Readhead
       Definitive Detection of Excess Arcminute Scale    
       CMB Anisotropies                                  
  GBT06A-027 [F B] Karen Masters
       Mapping Matter in the Nearby Universe with 2MASS  
  GBT06A-038 [F  ] Tom Troland
       Magnetic Fields in the Galactic Halo via the HI   
       Zeeman Effect                                     
  GBT05C-026 [FP ] Tom Devlin
       Polarization of 30 GHz emission from              
       extra-galactic sources                            
  GBT06A-019 [F B] Rachel Osten
       Wideband Dynamic Spectroscopy of Coherent Radio   
       Bursts on Active M Dwarfs                         
  GBT06A-009 [ P ] Jim Condon
       H_0 and Dark Energy                               
  GBT01A-005 [ P ] Barry Turner
       A High-resolution Spectral Survey Of Tmc-1 At     
       Q-band                                            
** Scheduled as F-ixed, P-rimary, B-ackup

Contact Information for 04/13/2006 - 04/27/2006
=======================================
Proposal   PI                 Bands Email [NRAO contact]    
---------- ------------------ ----- --------------------
GBT06A-032 Jim Braatz         Q     jbraatz@nrao.edu [Jim Braatz]
GBT06A-065 Rachel Friesen     K     rfriesen@uvastro.phys.uvic.ca [Toney Minter]
GBT06A-054 Paul Demorest      L     demorest@astron.berkeley.edu [Scott Ransom]
GBT06A-044 Jeremy Darling     6     jdarling@origins.colorado.edu [Frank Ghigo]
GBT06A-011 Mike Blanton       L     blanton@nyu.edu [Karen O'Neil]
GBT05B-042 Michael Kramer     L8    mkramer@jb.man.ac.uk [Scott Ransom]
GBT06A-022 Jim Braatz         K     jbraatz@nrao.edu [Jim Braatz]
GBT06A-056 Paul Kondratko     K     pkondrat@cfa.harvard.edu [Jim Braatz]
GBT05C-042 Scott Ransom       8     sransom@nrao.edu [Scott Ransom]
GBT06A-046 Glen Langston      U     glangsto@nrao.edu [Glen Langston]
GBT05C-065 Jim Braatz         K     jbraatz@nrao.edu [Jim Braatz]
GBT05C-022 Jim Braatz         K     jbraatz@nrao.edu [Jim Braatz]
GBT06A-047 Miguel Angel Reque K     requena@damir.iem.csic.es [Ron Maddalena]
GBT04C-043 Scott Ransom       8     sransom@nrao.edu [Scott Ransom]
GBT06A-014 Andrea Tarchi      K     atarchi@ira.cnr.it [Jim Braatz]
GBT06A-003 Chris Clemens      L     clemens@physics.unc.edu [Scott Ransom]
GBT05C-033 Marko Krco         L     marko@astro.cornell.edu [Karen O'Neil]
GBT06A-026 Nissim Kanekar     6     nkanekar@nrao.edu [Toney Minter]
GBT06A-004 William Reach      K     reach@ipac.caltech.edu [Toney Minter]
GBT05C-023 Fernando Camilo    8     fernando@astro.columbia.edu [Scott Ransom]
GBT06A-027 Karen Masters      L     kmasters@cfa.harvard.edu [Karen O'Neil]
GBT05C-046 Ingrid Stairs      L     istairs@astro.ubc.ca [Scott Ransom]
GBT06A-039 Fernando Camilo    S     fernando@astro.columbia.edu [Scott Ransom]
GBT06A-006 Wouter Vlemmings   K     wouter@jb.man.ac.uk [Karen O'Neil]
GBT06A-018 Joe McMullin       Q     jmcmulli@nrao.edu [Dana Balser]
BB223      Norbert Bartel     S     bartel@yorku.ca []
GBT05C-019 Tim Robishaw       L     robishaw@astro.berkeley.edu [Toney Minter]
GBT06A-050 Steve Begin        S     sbegin@physics.ubc.ca [Scott Ransom]

Scheduled hours [backup]
========================
Category/Month-> March     April     May       
    Astronomy ~  575 [005] 547 [486] 514 [328] 
  Maintenance ~   50        16 [102]  20 [068] 
  Test & Comm ~  118       150 [046] 151 [041] 
  Un-assigned ~    2         9        59       

Proposal Checkouts
==================
Awaiting checkout - 0
  Active checkout - 0
          On Hold - 21
         Schedule - 59
        Completed - 471


Current backlog [hours prior to 06A*] = 984
   [2001:2(1), 2002:88(2), 2003:19(1), 2004:141(10), 2005:606(29), 2006:128(3)]
   Backlog excluding 111 hrs of monitoring projects after 06A = 873
Total time to discharge [hours] = 2459
   Includes 314 hours of monitoring after trimester 06A
* Includes projects that are on hold for trimester 06A

Microwave Electronics Status -- Roger

No problems.

Development

Ka RX, Zpectrometer: Concept development for zpectrometer rack continues.

Lab Spectrometer IF System: IF filters, second iteration have been fabricated. The 9.3 GHz filter looks good, testing of a second 9.3 GHz filter shows close matching. The 850 MHz filter tests closer to desired range but with a narrower bandwidth. A low pass/high pass combination is being investigated for the 800-1600 MHz IF filter. Flare transitions added to 50 ohm test lines show better S11 at low frequencies, worse at high frequencies

ORM Power Divider: First unit has been installed in the spare Optical Receiver module. We will be testing in the system over the next couple of weeks.

IF System: Converter/Filter amplifier upgrade - Changed the layout for T08 package, its cheaper, and also to better conform to the existing hole patterns. Also required a redesign of the mechanical box. This will reduce the work necessary for replacement.

Q-band: Completed vacuum window drawings for test dewar and delivered to shop. Completed layout drawings for amplifier and Atlantic Microwave septum polarizer.

C-band Upgrade: Designed LPF (fc=6GHz) 3/30/06, prototyping in progress (Tracy) on 3/30/06. Testing scheduled for 3/31/06. Revision of interface specifications, modeling gain/noise of room-temp electronics, and component selection. Mechanical modeling (Autocad dwg). Continue to work on design of cryogenic I/O coaxial lines, thermal straps, and interface definitions.

MLLN 140 Project: The boards are being populated with components. The connectors necessary for finishing the construction have arrived. The amplifier splitter should be completed next week.

31Mar06 - Norrod, Anderson, Simon, Stennes, Watts, White

Digital Electronics Status -- Rich

***Operations, Problem summary***

This week, there were no significant digital hardware problems.

***Development***

Cal-Tech Continuum Backend (CCB):

No progress.

Lab Spectrometer

Last week we reported completely garbled spectra coming out of this device. A driver problem similar to what was found in the GBT spectrometer was uncovered. With that fixed, some reasonable spectra were found in the 800 MHz mode. However, the spectra show up in two samplers with an input supplied to only one!

Because the Lab Spectrometer LTAs are both faulty, we are presently operating with spare GBT Spectrometer samplers. We plan to fix the Lab Spectrometer samplers before proceeding any further with system tests. The reason for this is that there is an outside chance that the GBT LTAs supply data to the computer in a different order than the Lab Spectrometer samplers. This could account for seeing spectra in two samplers with an input supplied to only one (not likely but possible).

Escoffier recalls providing spare cards and parts for the Lab Spectrometer. Whether they are in Green Bank or Socorro is not clear. We need to spend some time looking for these.

LTA Upgrade

Randy has continued to familiarize himself with the spectrometer in general and the LTAs in particular. His goal is to produce a design for an improved LTA.

Miscellaneous

ALMA

Jason Ray and Jack Nelson continue to spend time on ALMA bias modules and Rich on the ALMA correlator.

***Plans***

- Continue CCB construction... - Continue Test Spectrometer commissioning and attempt to find spares… - Complete Block Diagram of new LTA design... - Continue ALMA support as needed...

Software Status -- Amy

This ends Week 6 of 6 in the second development cycle of 2006 which can be viewed at PlanOfRecordC22006. We released C2 software this past Wednesday, March 29. Release notes were e-mailed to gbtlocal. The Plan of Record for next cycle is under development and can be found at PlanOfRecordC32006; it should be finalized in a day or so.

The following item was not released on Wednesday. However, we plan to patch it in once it is successfully sponsor tested:

• Add Motor Rack Vacuum/Refrigerator Control Functions (ModificationRequest1C106)

Operational support for this week was light and included:

• Investigation of instance when dynamic corrections were zero, although Model4c was supposedly loaded.
• GFM failing to receive LPCs/LFCs in a timely manner. Still under investigation.

Pulsar Related -- Scott

Claude-André Faucher-Giguère (a graduate student at Harvard and previous undergrad who worked with Vicky Kaspi at McGill? Univ) ran some simulations for me for a potential new S-band pulsar survey of the Galactic plane (using some form of multi-beaming system). Initial numbers indicate that it would find 200-500 new pulsars over the Parkes Multibeam Survey, including 30-50 new millisecond and/or binary pulsars.

Will be going to GB next week for a couple days to work on the spigot2 upgrade.

Finally, I was part of the Congressional Visits Day on Tues/Wed at the request of the AAS and met with a staffer of WV's Rep. Nick Rahall. I was encouraged by the staffer's statement that Rahall supports the proposed NSF funding requests. I was surprised to hear that she didn't think that Rahall had ever visited NRAO Green Bank, though! We should really change that! How about inviting him to the GB picnic this summer? I mentioned this to Mark Adams and will also mention it to Fred....

MIT/LL 43m Project -- Glen

Any other Business

-- RichardPrestage - 30 Mar 2006