GBT Operations & Commissioning Meeting
AGENDA
- I visited the steel mill and FEMCO's machine shop again this week.
- Continental's rep and I inspected 14 base plates. There was more variation in width in this lot. One was undersize and was rejected. This won't impact production as there are 2 extra plates. Mittal will replace this plate. The rest won't be ready until mid November.
- FEMCO has all 710 of the short studs machined - I'll bring one to the meeting. They look very good. The tensile strength is 145 ksi where we specified only 125 ksi. The nut fits well. It goes on easily and isn't loose. The remainder of the order will be machined in late November and shipped to us in December.
- FEMCO has also finished the machining of the spring plates for the 140' and have sent them to the heat treater. They should be back at FEMCO first full week in November. If they look all right, we will have them before Thanksgiving.
We supported 17 projects in 27 observing sessions. The telescope was scheduled for 17.5 hrs of maintenance, 2.5 hrs for program and receiver checkouts, 12 hrs for PAR commissioning and 12 hrs for KA-band commissioning. I will summarize the Ka-band commissioning results below.
Lost time was moderate this week -- 4.2 hrs or about 2.8% of the time scheduled for observing, commissioning, and tests. The number and diversity of problems is also larger than usual. Six of the fourteen operator shifts had no problems. The lost time was due to:
- Winds (3 instances) : 1.1 hrs
- Astrid (12 instances lockups, LPC failures) : 0.7 hrs
- Az Brake Circuit Breaker : 0.5 hrs
- Observer no show : 0.5 hrs
- Az Transducer : 0.3 hrs
- Spectrometer/Earth reboot : 0.4 hrs
- Optical Receiver 7 : 0.4 hrs
- Snow : 0.2 hrs
- Others : 0.1 hrs
I believe the number of Astrid problems is up due to more diligent reporting by the operators.
Last Week
=========
Observations for proposals
GBT06A-065, GBT05C-051, GBT06B-042,
GBT06B-044, GBT06C-032, GBT06C-011,
GBT06C-012, GBT06C-035, GBT06C-036,
GBT06B-015, GBT06B-037, GBT06C-037,
GBT06C-048, GBT06C-016, GBT06C-049,
GBT06B-018, GBT06C-006, GBT06C-008
Completed proposals
GBT06C-006
Next Week
=========
Observations scheduled for **
GBT05C-051 [ P ] Jim Braatz
A Snapshot Survey for H2O Megamasers in Nearby,
Luminous Galaxies
GBT06A-065 [ P ] Rachel Friesen
Probing the initial conditions of star formation
in Ophiuchus
GBT06A-054 [F B] Paul Demorest
Long-term Precision Timing of Millisecond Pulsars
GBT06C-021 [ P ] Erik Rosolowsky
A COMPLETE Census of Dense Cores in Perseus
GBT06C-032 [F B] Peter Martin
The Galactic foreground at the North Ecliptic Pole
GBT06C-055 [ B] Martin Zwaan
HI 21-cm absorption in MgII absorbers
GBT06A-014 [ P ] Andrea Tarchi
H2O vs Continuum in the Megamaser 3C403:
Reverberation Mapping of the Nucleus
GBT06C-012 [ B] Steve Curran
A Wide-Band Search of the Source of the
Obscuration of Reddened Quasars
GBT06A-026 [ B] Nissim Kanekar
A search for 21cm absorption towards MgII
absorbers in the redshift desert
GBT06C-035 [ P ] Jim Braatz
The Megamaser Cosmology Project: A Survey for H2O
Maser Disks in SDSS AGNs
GBT06C-036 [ P ] Claudia Cyganowski
Radio mapping of infrared interstellar bubbles
GBT06C-037 [ P ] Charlie Lada
Probing the Origin of Dense Cores and the Stellar
IMF
GBT06C-048 [F B] Nissim Kanekar
HI 21cm absorption in strong MgII and CI
absorbers in the redshift desert
GBT06C-016 [ B] Fernando Camilo
Studying the magnetar XTE J1810-197
GBT06C-027 [ P ] Walter Brisken
The impulse response of the universe
GBT06C-049 [F B] Karen Masters
Mapping Matter in the Nearby Universe with 2MASS
GBT06C-039 [ P ] Jim Braatz
The Megamaser Cosmology Project: Circumnuclear
Disk Accelerations
BM251 [F ] Neal Miller
High Sensitivity Array Observations of the
Intermediate-Mass Black Hole in J170902+641728
GBT06B-019 [ B] Toney Minter
Obtaining A Complete Sample Of Pulsar OH
Absorption With The GBT
** Scheduled as F-ixed, P-rimary, B-ackup
Contact Information for 11/09/2006 - 11/23/2006
=======================================
Proposal PI Bands Email [NRAO contact]
---------- ------------------ ----- --------------------
GBT06C-051 Lincoln Greenhill K greenhill@cfa.harvard.edu [Jim Braatz]
GBT06B-042 Nissim Kanekar 3 nkanekar@nrao.edu [Larry Morgan]
GBT06C-052 Scott Ransom S sransom@nrao.edu [Scott Ransom]
GBT06B-032 Steve Begin S sbegin@physics.ubc.ca [Scott Ransom]
GBT06C-020 Rachel Friesen K rfriesen@uvastro.phys.uvic.ca [Toney Minter]
GBT06B-055 Nissim Kanekar 8 nkanekar@nrao.edu [Toney Minter]
GBT06B-033 Jason Hessels 8 jhessels@science.uva.nl [Scott Ransom]
GBT06B-044 Robert Ferdman L ferdman@phas.ubc.ca [Scott Ransom]
GBT06A-056 Paul Kondratko K pkondrat@cfa.harvard.edu [Jim Braatz]
GBT06C-032 Peter Martin L pgmartin@cita.utoronto.ca [Jay Lockman]
GBT06C-021 Erik Rosolowsky K erosolow@cfa.harvard.edu [Ron Maddalena]
GBT06C-011 Steve Curran L sjc@phys.unsw.edu.au [Carl Bignell]
GBT02A-054 Ingrid Stairs L istairs@astro.ubc.ca [Scott Ransom]
GBT06C-012 Steve Curran L sjc@phys.unsw.edu.au [Carl Bignell]
GBT06B-014 Paulo Freire 3 pfreire@naic.edu [Scott Ransom]
GBT06A-004 Bill Reach K reach@ipac.caltech.edu [Toney Minter]
GBT05C-023 Fernando Camilo 8 fernando@astro.columbia.edu [Scott Ransom]
GBT06C-035 Jim Braatz K jbraatz@nrao.edu [Jim Braatz]
GBT06C-003 Tony Remijan K aremijan@nrao.edu [Larry Morgan]
GBT06C-004 Tony Remijan K aremijan@nrao.edu [Larry Morgan]
GBT06C-037 Charlie Lada K clada@cfa.harvard.edu [Frank Ghigo]
GBT06C-016 Fernando Camilo S8XC fernando@astro.columbia.edu [Scott Ransom]
GBT06C-038 Jay Lockman L jlockman@nrao.edu [Jay Lockman]
GBT06C-049 Karen Masters L kmasters@cfa.harvard.edu [Larry Morgan]
GBT06B-018 Michael Kramer 8 mkramer@jb.man.ac.uk [Scott Ransom]
Scheduled hours [backup]
========================
Category/Month-> October November December January
Astronomy ~ 592 [087] 465 [394] 542 [318] 566 [345]
Maintenance ~ 70 45 [051] 52 [034] 55 [068]
Test & Comm ~ 83 172 [007] 87 54 [016]
Shutdown ~ 0 36 36 0
Un-assigned ~ 0 4 32 76
Proposal Checkouts
==================
Awaiting checkout - 0
Active checkout - 0
On Hold - 16
Schedule - 71
Completed - 565
Current backlog [hours prior to 06C*] = 979
[2001:2(1), 2002:0(4), 2003:19(1), 2004:107(21), 2005:469(24), 2006:382(21)]
Backlog excluding 162 hrs of monitoring projects after 06C = 817
Total time to discharge [hours] = 2744
Includes 250 hours of monitoring after trimester 06C
* Includes projects that are on hold for trimester 06C
- Supported various Penn Array tests
- GBT LO System support for radar backend.
- Optical link #7 is dead
- Installed Zpectrometer Wednesday. Will be checked out by UMd next Tuesday
- Upgrade of converter/filter modules continues.
- SN3 buffered power divider checked out OK. Will be installed into the system. Construction of the other units continues.
- RF testing of C band starting
- Design of integrated C band receiver components continues
- Analysis, and later discussions, led to the elimination of the RF preselector filter bank from the design.
- Designed 3.8-6.2 GHz bandpass filters.
- Designed IF power dividers.
Digital Group Status 21-OCT-06 THRU 27-OCT-06
***Operations, Problem Summary***
Active Surface...
One LVDT module was replaced which re-activated a patch of 16 previously disabled actuators.
Quadrant Detector...
While attempting to fix the previously reported bad thermocouple, we discovered that everything at the illuminator end was dead. We then discovered that a bad feedthru filter in the Receiver Room bulkhead was tripping an AC breaker. Bob Simon assisted with the replacement of this filter (which restored AC power); however we ran out of time to fix the thermocouple. Plans are to fix the thermocouple next week.
***Development***
Caltech Continuum Backend (CCB)...
Construction of CCB #3 is still underway with a newly revised completion date of 17-NOV-06.
Spectrometer LTA Re-design...
Following the design review, Ray Escoffier has made a series of suggestions regarding possible fixes for the existing LTA design, so this week has been spent conducting tests surrounding these suggestions. Since it would obviously be better to fix the existing design rather than start over from scratch, we intend to spend the next two weeks exhausting the possibilities. The target date for making a decision is 09-NOV-06; at which point we will have decided on a plan of attack and revised the proposed project schedule.
ALMA (As reported by Jason Ray)...
- On-going efforts are continuing smoothly on the ALMA front.
- A total of 11 rev C boards arrived from Data Translation. Testing of these boards is underway now in an effort to deliver four completed modules to CV ASAP.
***Plans***
- Continue Active Surface maintenance as required...
- Repair bad thermocouple on the Quadrant Detector...
- Continue construction of CCB #3...
- Continue testing existing LTA design ...
- Deliver 4 ALMA modules to CV ASAP and continue support as needed...
Randy
This ends the 4th week of 6 in the seventh development cycle of 2006 which can be viewed at PlanOfRecordC72006. We are scheduled to release at the end of January 2007. Items deemed ready for release before that time will be patched in after they have been fully tested.
Operational support was relatively busy this week and included:
- Recovery from Spectrometer host crash.
- More work on GO FITS RA issue.
- Looked into Archivist failure to log QD data.
- Answered questions concerning a configuration that was run on 10/21.
- Provided user support with GBTIDL over plot bug.
- Answered questions concerning default configuration keyword values from TM (for documentation purposes).
- gbtstatus failed because daemon quit. Restarted.
- Astrid failed because es daemon quit. Restarted.
Modification Requests:
- MRs ready for integration/regression testing:
- MRs ready for sponsor testing:
- MRs under development
- MRs under CCC review:
- MRs being written:
- Modify SDFITS to correctly show Spectrometer cross-polarization data (ModificationRequest2C706)
- MR nearly finished, waiting for feedback from Heiles and Robishaw. Design changes to sdfits seem low impact.
- Investigate & Fix Cause of Astrid Hang-ups (ModificationRequest3C706)
- Continuing refactoring and optimization, see MR, a living document.
- GFM/Turtle Upgrade - Remove use of LPCs.conf file (ModificationRequest4C706)
- MR written and checked. Preliminary client code in GFM written.
- Other Activities:
- Dynamic Scheduling - Analysis and evolution of requirements begun. Meetings everyday. Continuing progress on defining terms and selection rules. Adding use cases.
- Penn Array Commissioning Support - We have a change to the Housekeeping software log file format ready for patching into the on-line system. MelindaMello talked with BrianMason about what needs to be done with PAR software.
- Balancing Project - MelindaMello ran tests using the IF Rack during maintenance. When performing balancing within the IF Rack, the SIB performance was roughly per spec. The delays come from a 50 mSec wait state after EACH attenuator is set. The Manager code does each ifpath sequentially, thus the 50 mSec waits are cumulative. Another problem is that the wait state occurred even if the IF Rack path was already balanced. Thus the minimum time per path was approximately 55 mSec. I removed this unnecessary wait condition and the minimum time for a balance per ifpath when already balanced dropped to about 4 mSec. This code is neither released or committed. MelindaMello will write a brief report on the findings and recommendations.
- Zpectrometer Support - Obtained network ports and IP addresses for move to receiver room.
- PTCS Support - Revising Project Note PTCSPN52 based on recommendations from FrankGhigo to include more quantitative comparisons.
PTCS Report -- John
I was asked last week to start reporting on PTCS activities. This week's report is just a listing of what we're doing, instead of listing progress. Here goes:
- Servo system improvements
- Work to fix the harsh starting of a scan, and the problem of poor tracking at low az/el velocities -- Winter '06
- Servo interlock system replacement
- Replace hard-wired interlock board with PLC for remote troubleshooting and diagnostic capability -- Summer '07
- Small-scale surface error characterization
- Holography? Photogrammetry? Other? -- Summer '07
- LRFV2 development
- Develop productized (reliable, small, robust operation) -- Fall '07
- Wind effect studies
MIT/LL 43m Project -- Glen
Week of spacecraft tracking. We have had some issues with
the servo-computer detecting an overspeed error condition that Tim W.
is looking into.
We are meeting next week at JPL to discuss ground tracking for
the VSOP=2 Space VLBI project.
Q-band was installed on Friday a week or so ahead of schedule but we aren't planning to start commissioning until after Ka-band commissioning. Zspectrometer will be installed this week with tests starting next.
This week we had 12 hrs of PAR commissioning and 12 hrs of Ka-band commissioning. PAR's latest run had some more problems with cryogenics and they will be warming up before attempting more cryogenics tests. This week may be the last time this fall that PAR will use telescope time. Cryogenic tests might requirte that the receiver be on the telescope an extra week, which should have no impact on any of our other plans.
We're still pouring over Ka-band tests. Our first night's data was hurt by what we believe is a config-tool bug in how L1 and the MM-Converters are being set up. Baseline tests from 8 hrs of observing the NCP are very promising -- noise remains theoretical and all shapes in the bandpass are similar to what we see with all other receivers and which can be attributed to either feed resonances or structure in Trx.
We're seeing ~5-10% 'bleed through' from one channel to another, which we believe is due to gain imbalances between the hybrid. This results in ~20% calibration errors that we think we might be able to correct. The correction might also improve baseline shapes. More importantly, we believe the 'bleed through' might amount to a 20% degradation in the effective telescope efficiency. Ka-band commissioning continues for the next 2 or so weeks.
- Every month : Pointing -- 1 night/month except in November, A/B weather, dynamically scheduled.
-
Week of Sep 4 : C-band off telescope
- Week of Sep 11: Penn Array on telescope in C-band slot
- Sept 11 - Oct 27 : Penn Array commissioning -- 1 night/week, A-weather, dynamically scheduled. 8 nights max.
- Sept : Ka-band, Q-band, Zpectrometer lab tests
- Week of Oct 2 - week of Oct 12 : Penn Array backup daytime engineering time : 4 day-times max.
- On or before week of Oct. 9 : Ka-band placed on telescope
- Oct 16 - Nov 13: Ka-band spectral-line commissioning -- 1 night/week, A-weather, dynamically scheduled. 3 nights max.
- Oct 16 - Nov 13: CCB quick checkout (2-3 hours), time permitting.
- Week of Oct. 23 (earlier if it's practical and if the astronomy schedule has no conflicts): Ku-band down , X-band moved to where Ku-band was , Zpectrometer on telescope where X was
- On or before week of Oct. 30 : Q-band on telescope
- Oct 31 : Fixed maintenance day for Zpectrometer checkout
- No later than week of Nov. 6 : Penn Array down, C-band up in its place.
- Nov 6 - Dec 14 : Q-band commissioning -- 1 night/week, A-weather, dynamically scheduled. 3 nights max.
- Nov 13 - Dec 1 : Ka-band CCB continuum commissioning and Ka-band Zpectrometer testing -- Sharing four dynamically scheduled, daytime/evening sessions (~noon to ~midnight) for A/B weather. Zpectrometer will have up to ~ 25 hrs, CCB the remaining ~ 15 hrs.
- After Dec. 1 : Ka-band observations can commence, preference given to low-risk continuum projects.
- No later than week of Dec. 4 : Zpectrometer down, Ku-band up where Zpec was.
- Dec. 11 - Dec. 21 : PTCS OOF Tests -- A-weather, dynamically scheduled, 2 nights max.
- After Dec. 15 : Q-band observations can commence.
- C-band, Remove: week of Sep 4 , Install: no later than week of November 7
- Penn Array, Install: week of Sep 11 , Remove: no later than week of Oct 31
- Ka-band, Install: on or before the week of Oct 9
- Zpectrometer Install: week of Oct 23; Remove: no later than week of Dec 4
- Ku Remove: on or before week of Oct 23 ; Install: no later than week of Dec 4
- X-band moved to Ku-band slot: on or before week of Oct 23
- Q-band, Install: on or before the week of Oct 30
-- RichardPrestage - 19 Oct 2006
Revision r1.12 - 27 Oct 2006 - 13:42 GMT - RichardPrestage
Parents: WebHome > CommissioningMeetings
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