GBT Operations & Commissioning Meeting
AGENDA
Activities List
GBT: The painters have put primer on all of the steel components and the grout. The foundation coating arrived yesterday afternoon, and they'll begin putting that on today.
20m: The mechanics and Bob Goldizen began servicing the drives this week. We hope to be able to tip and check out the Sterling mount in the next couple of days. There is a report that a bearing had failed in one of the mount motors prior to mothballing.
43m: The new brake springs are still in manufacture, but getting close. So far, all 6 are within specified tolerances.
We supported 8 projects in 20 observing sessions. PTCS used 74 hours, servo tests 10 hrs, maintenance 8.5 hrs. A few miscleaneous problems during observing:
- Spectral Processor/Converter Rack power levels : 0.6 hrs
- Spigot : 0.6 hrs (2 instances)
- Astrid : 0.6 hrs (2 instances)
- Az Tachometer : 0.6 hrs
- Power Outage (Remote observer) : 0.4 hrs
- Scheduling -- source not up : 0.2 hrs
- Ku-band MCB and S-band Cryo : NLT
The loss of the S-band cryo required a change in the observing schedule for last night. The observer encountered power level problems with the Spectral Processor and did not call up support for an easy fix. Toney distributed an e-mail describing the symptoms and solutions.
Last Week
=========
Observations for proposals
GBT07B-011, GBT07C-067, GBT06B-037,
GBT07B-017, GBT07B-006, GBT07B-008,
GBT07A-060
Completed proposals
GBT07B-011, GBT06B-037, GBT07B-017
Next Week
=========
Observations scheduled for **
GBT07C-067 [F B] Helene Courtois
Bulk Motions of Filaments in the Local Universe
GBT07B-014 [ B] Marta Burgay
A deep pulsar search in the candidate Pulsar Wind
Nebula in DA 530
GBT07B-006 [ B] Fernando Camilo
Studying the magnetar XTE J1810-197
GBT07B-007 [F B] Nissim Kanekar
A search for 21cm absorption in strong MgII
absorbers in the redshift desert
GBT07A-060 [ B] Julia Deneva
S-band Drift Search for Transients and Pulsars in
the Inner Galaxy
** Scheduled as F-ixed, P-rimary, B-ackup
Contact Information for 09/27/2007 - 10/11/2007
=======================================
Proposal PI Bands Email [NRAO contact]
---------- ------------------ ----- --------------------
BB240 Geoff Bower X gbower@astro.berkeley.edu []
GBT07A-087 Paul Demorest L demorest@astron.berkeley.edu [Scott Ransom]
GBT07C-020 Fernando Camilo S fernando@astro.columbia.edu [Scott Ransom]
GBT06C-020 Rachel Friesen K rfriesen@uvastro.phys.uvic.ca [Toney Minter]
GBT07A-089 Fernando Camilo 8 fernando@astro.columbia.edu [Scott Ransom]
GBT07B-034 Robert Ferdman L ferdman@phas.ubc.ca [Scott Ransom]
GBT07C-044 Maura McLaughlin 83 maura.mclaughlin@mail.wvu.edu [Scott Ransom]
GBT07C-033 Jason Hessels 38 jhessels@science.uva.nl [Scott Ransom]
GBT07C-045 Shea Brown L brown@physics.umn.edu [Toney Minter]
GBT07C-067 Helene Courtois L courtois@ifa.hawaii.edu [Rick Fisher]
GBT07B-025 Scott Ransom S sransom@nrao.edu [Scott Ransom]
GBT06C-045 David Champion S champion@physics.mcgill.ca [Scott Ransom]
GBT07C-036 Yancy Shirley K yshirley@as.arizona.edu [Paul Ruffle]
GBT07B-005 Sharon Montgomery L smontgomery@clarion.edu [Frank Ghigo]
GBT07A-029 Dick Crutcher L crutcher@uiuc.edu [Toney Minter]
GBT07B-006 Fernando Camilo S fernando@astro.columbia.edu [Scott Ransom]
GBT07B-029 Michael Kramer L mkramer@jb.man.ac.uk [Scott Ransom]
GBT07B-007 Nissim Kanekar 8 nkanekar@nrao.edu [D.J. Pisano]
GBT07C-029 Amanda Kepley X kepley@astro.wisc.edu [Toney Minter]
GBT05A-029 Paul VandenBout B pvandenb@nrao.edu []
GBT07A-060 Julia Deneva S deneva@astro.cornell.edu [Scott Ransom]
GBT07A-094 Scott Ransom S sransom@nrao.edu [Scott Ransom]
GBT07A-050 Claudia Cyganowski K ccyganow@astro.wisc.edu [Toney Minter]
GBT07A-072 Lisa Wei L wei@astro.umd.edu [Frank Ghigo]
GBT07C-060 Fernando Camilo 8S fernando@astro.columbia.edu [Scott Ransom]
Scheduled hours [backup]
========================
Category/Month-> September October November December
Astronomy ~ 131 [295] 575 [474] 559 [350] 421 [137]
Maintenance ~ 26 [051] 17 [085] 29 [068] 20 [068]
Test & Comm ~ 555 [031] 101 [020] 58 [032] 68
Shutdown ~ 0 0 36 36
Un-assigned ~ 9 51 39 209
Proposal Checkouts #[hrs]*
=========================
Awaiting checkout - 0[0]
Active checkout - 0[0]
On Hold - 0[0]
Schedule - 115[4322]
Completed - 491[6289]
* All but completed queue applies to GBT only proposals
Current backlog of Reg & RRS proposals [hours prior to 07B*] = 1161
[2005:369(14), 2006:349(16), 2007:444(21)]
Backlog includes 59 hrs of monitoring projects
182 hrs of vlbi projects
Total time to discharge [hours] = 6468
Includes 299 hours++ of monitoring (not Large or Spec) after trimester 07B
2758 hours of Regular & RRS proposals
3317 hours of Large proposals
30 hours of Track Refurbishment proposals
364 hours of VLBI proposals
* Includes projects that are on hold for trimester 07B
++ Time is counted in other break down as well. 07B
- Ku band removed for repair. Repair begins week of September 17.
- S band warmed for refrigerator swap. Back in service September 14.
- Ka band ready to be installed for Astronomical checks.
- MM converter installed and ready for use.
- Q band testing continues, nothing definitive on source of problems.
- C band mechanical parts installed. Testing should begin week of September 17.
Digital Group Status 08-SEP-07 THRU 14-SEP-07
***Operations, Problem Summary***
No significant events to report this week.
***Maintenance***
Active Surface...
Last week, one LVDT module created a cascading failure resulting in 64 actuators being taken out of service. The offending LVDT module (and fuse) were repaired, which brought the 64 actuators back into service.
***Development***
CICADA (Advanced Digital Backends Program)...
- A very successful and useful VNC/Telecon session was held Thursday afternoon during which Glen demonstrated CASPER's version of their Pocket Spectrometer using live sky data from the 43m telescope and various test tones generated in the lab. However, subsequent attempts to build and load our own version of this design during the same session were unsuccessful; so the plan is to have Brandon Rumberg continue his efforts to build a working NRAO version of the Pocket Spectrometer.
- Another VNC session has now been set up with CASPER for this Friday afternoon in an effort to overcome our on-going problems with our attempts to build and load the current version of their Pocket Spectrometer.
- 10 GbE? hardware has arrived, racks are being built, and UPS and computers are on order.
- Xilinx kindly provided a second software development platform at no charge
- Mathworks software is on order.
- Settled on a name for the new pulsar machine: GUPPi
Spectrometer LTA Re-design...
- All LTAs in all four Quadrants have been upgraded (a total of 8).
- Early tests indicate a significant improvement in performance vis-a-vis the "bad lags" issue.
- A 9th LTA has now been successfully upgraded, tested, and placed in our spares.
- The plan now is to upgrade the Lab Spectrometer's two LTAs once the current RX testing is concluded.
PTCS...
The electronics have now been completed and tested for the new accelerometer set. A new mount will be fabricated following Dennis Egan's review, and the new accelerometer set should be installed by 05-OCT-07.
ALMA...
On-going efforts are continuing fairly smoothly on the ALMA front.
***Plans For Next Week***
- Continue to monitor GBT Spectrometer LTA upgrade program performance...
- Continue work on GUPPi project, Phase 1...
- Continue ALMA efforts as required...
Randy
We replaced an A/D module in the basement PLC remote unit to try to fix intermittent "Pre-Charge Pressure" warnings. I've asked a couple operators and they have not seen the bogus yellow warnings since. (43M Telescope)
Last week we had a review of the GBT PLC Interlock Upgrade. This week I updated ladder logic and hardware to address the issues from that meeting.
On Wednesday we had the GBT from 8:00am till 6:00pm. We re-tested the PMU/MRU/MSU interfaces for elevation, the El stow pin, and did our first tests on movement in azimuth. Moving in azimuth went great.
We checked the acceleration in both axes and they were dead-on (0.1deg/sec/sec).
We checked the polarity of all the statuses that will be sent to the CCU, they looked fine.
We tweaked the interface between the PLC and the PMU/MRU to make it easier to turn off.
We are now ready to begin our interface over the Modbus with the CCU.
When the Modbus interface is completed we will need 2-3 days to do formal Servo tests to guarantee the PLC system is fully tested.
We are in the sixth development cycle of 2007. Please see the PlanOfRecordC62007 for all of the division's assigned activities. Effort metrics for Cycle 5 are now available; please see MetricsC52007. Our next release is scheduled for Wednesday, October 3. Integration testing begins the week of September 24th.
Operational and user support over the last two weeks was light and included:
- Responded to a report that the RcvrPF_1, MM Converter, and Rcvr12_18 Managers crash when the MCB is not connected. This issue will be fixed in the upcoming release.
- Responded to a report that GFM couldn't plot peaks due to NULLs in Antenna data.
- MRs ready for release:
- MRs ready for sponsor testing:
- Implement PFM5 revised pointing/focus model (ModificationRequest1C407)
- Note - This MR was released as part of M&C v7.5 to simplify sponsor testing. Sponsor is actively working on testing numerical results using test program. Continued to work with sponsor on testing. No issues identified with the new PFM5 yet, but a term seems to be missing in the antennaCharacterization database expression in the current Gregorian model.
- MRs under development:
- Port Holography Manager to Linux (ModificationRequest1C307)
- Testing fix of MCB comm issues with new Linux platform. Finishing up unit tests. Working on simple data simulator via MCB simulator. Plan to release to sponsor for testing next week.
- Modify Peak Finding Algorithm for Pointing/Focus Code (ModificationRequest4C207)
- FrankGhigo and ToddHunter have settled on GaussianFilter as preferred method. However, since this approach changes the resultant pointing offset values, deployment of the selected approach will be postponed until after the new pointing model is implemented this summer.
- SCCU Servo Changes (ModificationRequest1C806)
- Although the code is working, we have found that commanded velocity spikes occur during normal observing. To date this has not been a problem since the hardware filters out the spikes. However with the hardware modifications coupled with this MR, the spikes will corrupt the intended operation of the friction compensation. John is working on modeling a different methods of deriving the velocity commands.
- Subreflector Nodding Observing API Building Block (ModificationRequest17C507)
- Most implementation and unit testing completed, still need to retrofit focus scans. Final simulation test will start next week.
- Control of Subreflector Nodding by Astrid (ModificationRequest2C407)
- Waiting for completion of SubMotion building blocks (17C507)
- Correct Labeling of Ka-band Hybrid-Switched Signals (ModificationRequest3C407)
- May not be ready for upcoming release.
- Merge Zpectrometer code branch into main trunk (ModificationRequest15C507)
- The gbtidl part of the code merge MR is done, starting work on the sparrow part. The changes to support the new organization of /home/sdfits are almost ready in gbtidl.
- Mustang Manager Meta-MR (MasterMustangManagerMr)
- Links all of the sub-MRs together.
- MRs under CCC review:
- Mustang Crate Control (ModificationRequest16C507)
- Paul has coded most of the necessary low-level serial port commands and has coded and tested all parameters whose values can be checked using our in-house parser! Need to agree on design issues for remaining parameters, and need to clean up code a bit as well. Good Progress! Experimenting with stand alone parser to support tests.
- Mustang Tower Control (ModificationRequest14C507)
- Tower Parameters coded and tested in simulator, but no hardware to test with.
- MRs ready for sponsor signature:
- MRs being written:
- Add DIO interface to Linux Holography Manager (ModificationRequest12C507)
- Revising MR to reflect recent team discussion about interrupt characteristics of new interface card, and the effects this will have on software design.
- Implement GBTIDL Reduction Procedure for Subreflector Nodding (ModificationRequest5C507)
- Another round of feedback send back to Ron and others.
- Ka Manager Changes (ModificationRequest1C507)
- Tabled MRs:
- Other Activities:
- Complete Pointing Processing Description Memo - Work being performed as part of implement model 5 task above. Needs some cleanup to include focus tracking.
Nothing to report really. General network performance on the GBT is showing lower latency and the new equipment will shortly be included in the NRAO wide network monitoring system.
The new Cisco switch in the servo room failed Friday at about 3:30 A.M. Joe Brandt and John Ford replaced it with the spare, and after consultation with Derek got it working by rebooting the Allied-Telesyn switch.
PTCS -- PTCS Team
Kevin began working on a simulink model of the telescope to allow us to model the effects of the servo system and try to find the servo resonance problem. Also working to help us figure out what to do to replace our Glish scripts, which we have been warned yet again will no longer work after the end of the year.
In the collection of pointing data for deriving
a new model, we have so far about 60 hours of
all-sky pointing, two sets of slow azimuth rotations,
about 12 hours of half-power tracks, and
12 hours of single-source peaks.
The plan calls for additional runs of
-- about 24 hours all-sky pointing in higher winds
(preferably > 10 MPH)
-- another two 12 hour sessions of half-power tracks,
-- another 12 hours of single source peaks.
Kim is working on generating a new pointing model;
not sure when it will be ready, but we are hoping
in about a week or so.
-- Frank
More progress on the new pulsar backend. Looks like the pocket spectrometer (at least one incarnation) works on the iBob. That is very close to phase I of the pulsar backend (i.e. basic Spigot replacement). We've also agreed on GUPPI as a name. Green bank Ultimate(?) Pulsar Processing Instrument (or something similar).
Paul Demorest made some great progress with the GPU programming last week and showed that a single GPU can coherently dedisperse 40-50MHz of BW at DMs up to several hundred. To put that in perspective, the GASP+CGSR2 clusters together can only process that amount of BW for high-DM pulsars. If we wanted to make the coherent de-dispersion machine in GPUs instead of iBOB+BEE2, it would likely take a cluster with ~1 dozen nodes and 2 dozen GPUs. Total cost would be $30-40K -- much better than the several hundred thousand it would take to do it all in CPUs. iBob+BEE2 will still be better, though, (less power, cooling, and more reliable) assuming we get it to work.
Finally, it appears that both of the new 8-bit Spigot modes (50MHz BW mode 54 and 800MHz BW mode 14) work correctly through Astrid and can be automatically calibrated mostly correctly (there is large ripple in the band, though, that is not there in the 16-bit calibrations). Last night, I measured the absolute timing offsets of these modes with respect to the BCPM, and so they are ready for use by any and all.
- Normal space object tracking
- Some tests with GPS tracks were successful, but need to clean up our interfaces.
- moving all wiki.gb.nrao.edu contents to wikio.gb.nrao.edu
Ku-band was removed this week in preparation for Zpec installation. PTCS and Servo tests were performed according to plans. We are expecting Ka-band to be installed next week.
-
July 17 through Aug 1 : L-Band refrigerator work. Must be completed for Governor's school
- Aug 1 through Aug 31 (originally Aug 17, the end of track shutdown) : Reinstall Q-band; pump and cool.
- Aug 6 : Install Mustang
- Aug 6 through no later than Sept 7 : Mustang tests
- By Aug 13 (Originally Aug 10) : Decision as to whether we will use this fall the one polarization configuration of Ka-band.
- By Aug 10 (1 week before end of track shutdown) : Install S-band and X-band. The receivers will already be cold when they are installed. Due date is set by the end of the track repairs and so may slip forward or backward. Installing by Aug 10 is preferable since that will give us time for receiver checkouts during the track shutdown.
- By Aug 31 (originally Aug 17, the end of track shutdown) : receiver checkouts for S-, X-, and Q-band. Includes pulsar checks of new S-band filters. Two nighttime 4 hr sessions per week, the LST is to be determined.
- (New Item) Aug 27 Remove Q-band from telescope to investigate high Tsys in one channel.
- Aug 31 - Sept 15 (originally Aug 17 - Aug 30, the end of shutdown to 2 weeks later) : Contingency test time for any remaining S-, X-, and Q-band receiver checkouts. (K-band was added after these plans were formed.) One nighttime 4 hr sessions per week. Dynamically scheduled.
- Aug 31 (originally Aug 17, the end of track shutdown) : start of PTCS recommissioning of the track
- No later than Sept. 3 : K-band pumped and cooled
- No later than Sept. 10 but no sooner than 1 week after K-band is cold: K-band receiver checkout. Dynamically scheduled.
- No later than Sept 7 : Mustang removed
- Sept 28 (originally Sept 14, four weeks after the end of track shutdown) : End of PTCS recommissioning of track
- Week of Sept 17 or Sept 24 : Install Ka-band. Contingent on Aug 10 decision.
- Before Sept 24 : Ku-band removed to make room for Zpec. No need to cool Ku until it is reinstalled (Nov?). Contingent on Aug 10 decision.
- Week of Sept 24 or Oct 1: Install Zpec. Contingent on Aug 13 decision.
- No later than the week of Sept 24 : Q-band reinstalled and receiver checkout (8 hrs)
- Sept 23 - Sept 30 : SDD software tests for Oct 3 release
- Week of Sept 24, Oct 1, and Oct 8: Ka-band/Spectrometer recommissioning. Contingent on Aug 10 decision. One 8 hr sessions per week of A-class weather (nighttime, dynamically scheduled).
- Oct 1 - Oct 13 : Zpec commissioning, A and B weather, dynamically scheduled. Contingent on Aug 10 decision.
- Oct 7 - 15 : CCB/Ka testing, A-class weather (nighttime, dynamically scheduled).
- No later than week of Oct 15 : Install C-band .
- Oct 18 : Decision as to whether to continue using the Ka-band single-pol configuration. Whether to schedule 100 hrs of Zpec observing. Whether to remove Ka and convert back to old configuration. Whether to proceed with Ka/Spec/CCB observing.
- Oct 21-Nov 2 : C-band astronomical commissioning, C-class weather
- Nov 2 : C-Band observing can start
- Nov 2 : Decision on how to proceed with traditional holography. Which receiver will we remove? When will tests start? Do we need to cut a mounting plate?
- Nov 2-15 : C-band baseline tests, C weather, and X-band baseline tests, B weather, dynamically scheduled.
- Week of Dec 3 : C-band removed, Mustang installed
- Dec 7 : Telescope at access for Mustang
- Dec 8 - week of Jan 15 : Mustang tests -- dynamically scheduled, A weather, nighttime.
- Week of Jan 21 : Mustang removed, C-band installed
- Feb 3-13: SDD software tests for Feb 13 release
-- RichardPrestage - 13 Sep 2007
Revision r1.14 - 14 Sep 2007 - 16:02 GMT - RonMaddalena
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