GBT Operations & Commissioning Meeting
AGENDA
Activities List
As of this morning, we are finishing the last Phase I main weld. The first 6 welds have been inspected and have passed. Alignment of Octant 5 plates is in progress, and should finish up this morning. The baseplates in this section will be welded to the splice plates this weekend, final machining of the baseplates will be done Monday, and Tuesday, wear plates installed Tuesday and Wednesday, and form work for grouting begun Thursday. Final height alignment will be done after the wear plates are installed, at night. We should be ready to move to Phase II in a week to ten days.
Last Week
=========
Observations for proposals
GBT07A-053
Next Week
=========
Observations scheduled for **
GBT07A-053 [F ] Dunc Lorimer
A 350-MHz drift-scan survey for pulsars with the
GBT
** Scheduled as F-ixed, P-rimary, B-ackup
Contact Information for 06/21/2007 - 07/05/2007
=======================================
Proposal PI Bands Email [NRAO contact]
---------- ------------------ ----- --------------------
GBT07A-053 Dunc Lorimer 3 Duncan.Lorimer@mail.wvu.edu [Scott Ransom]
GBT07B-012 Dunc Lorimer 3 Duncan.Lorimer@mail.wvu.edu [Toney Minter]
Scheduled hours [backup]
========================
Category/Month-> June July
Astronomy ~ 357 500
Maintenance ~ 347 203
Test & Comm ~ 17 42
Un-assigned ~ 0 0
Proposal Checkouts #[hrs]*
=========================
Awaiting checkout - 0[0]
Active checkout - 0[0]
On Hold - 0[0]
Schedule - 76[3571]
Completed - 491[6332]
* All but completed queue applies to GBT only proposals
Current backlog [hours prior to 07B*] = 4503
[2005:369(14), 2006:358(18), 2007:3777(29)]
Backlog includes 419 hrs of monitoring projects
1770 hrs of vlbi projects
Total time to discharge [hours] = 5361
Includes 626 hours of monitoring after trimester 07B
3137 hours of Large proposals
400 hours of Track Refurbishment proposals
178 hours of VLBI proposals
* Includes projects that are on hold for trimester 07B
- Removed Prime Focus I Receiver
- X band testing revealed a bad pin diode switch and a mangled RF connector, which we think was causing the intermittent problems. Baseline tests were completed: nothing unusual appeared. The plan is to open the X band dewar next week for possible absorber installation.
- Z-Spectrometer Ka Receiver tability tests completed with OMT removed. Waveguide parts were ordered to rework the receiver without the OMT for further baseline tests on the GBT. Continued testing of calibration ports revealed problems with SS cable: A rework of the cables is planned in an effort to improve the impedance characteristics.
- Second C band downconverter is assembled and ready for test.
- Third C band downconverter is ready for wire bond then test (~ 80% complete)
- Feed defroster is currently awaiting machined parts from the shop.
Digital Group Status 02-JUN-07 THRU 09-JUN-07
***Operations, Problem Summary***
Lab Spectrometer...
Roger reported another problem with the Lab Spectrometer not powering up. I Found and replaced a faulty -2V power supply which fixed the problem.
***Maintenance***
J.D. and Nathan spent the entire week working on servo system limits cabling upgrades for Tim Weadon.
***Development***
Spectrometer LTA Re-design...
The 1st article upgraded LTA board (with new FPGA adapter PCBAs installed) has undergone extended bench testing during which it performed 62,208 60-second integrations with NO errors. Attempts to install the 1st article into the Lab Spectrometer were unsuccessful. Given the fact that the GBT Spectrometer won't be needed again until 14-JUN-07, the plan is to install the 1st article there and conduct end-to-end tests with help from Karen.
ALMA...
On-going efforts are continuing fairly smoothly on the ALMA front.
***Plans***
- Continue daily check of Spectrometer exhaust fans...
- Begin testing the 1st article upgraded LTA in the GBT Spectrometer...
- Continue development efforts on Advanced Digital Backends Project...
- Continue ALMA efforts as required...
Randy
The feed arm partial rewire is going good. We are a couple days behind schedule.
We had planned that Prime Focus would be done Thursday 6/7. It will probably
be done Tuesday. This will put the subreflector partial rewire a couple days
later or into mid week (Wed 6/20).
All 24 Az/El motors were inspected by a Reliance Field Technician. They
are recommending we send 10 back to the factory for rework. Azimuth #7
appears to be burned up.
Tim has spent a couple days this week working on the PLC code for the 2007
Servo upgrade. About 75% of the Azimuth Status board PLC programming
is completed.
The hardware is all wired with the exception of the main
DC power supply. After the power supply and the service cord to power it
up is in place we can start debugging the hardware.
We are in the third full week of the fourth development cycle of 2007 which can be viewed at PlanOfRecordC42007.
Operational and user support was very light this week and included:
- Addressed hardware problems with antenna simulator.
- Support for air conditioning shutdown.
Modification Requests:
- MRs ready for integration/regression testing:
- MRs ready for sponsor testing:
- Fix Accelerometer Timestamping/Data Collection (ModificationRequest2C307)
- Sponsor testing has found a clock drift which is related to sample rate. Needs a fix for the GDAQ code. (On hold until Jason gets back.)
- Quadrant Detector Timestamp Fixes (ModificationRequest5C307)
- Sponsor testing has found a clock drift which is related to sample rate. Needs a fix for the GDAQ code. (On hold until Jason gets back.)
- MRs under development:
- 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.
- MRs under CCC review:
- MRs being written:
- Tabled MRs:
- Other Activities:
- Dynamic Scheduling - All effort went toward the external review.
- Analysis of Trajectory Generation Problems - Nothing to report.
- Find/Fix Command Stream Glitches - Attempting to find cause/source of velocity errors.
- Complete Pointing Processing Description Memo - No progress
- Complete Documentation of Cross-Polarization Changes - Almost complete.
- Evaluate GBT Data Handling Status & Future Options - In progress.
- Zpectrometer - Ray has been unable so far to simulate the Zpectrometer measurements because of a problem with the Antenna simulator that Joe is working on. In the meantime, Ray has inspected the Manager code to look for obvious problems, but found none. Ray has obtained some exact dates and times from Andy and Stephanie's observing log. Joe believes that with this information he can find out exactly what the Antenna was doing at the time. We can also look through other relevant log files and the message logs. In the meantime, Ray is running the Zpectrometer manager alone to see if there are any obvious issues with it.
GASP is once again having problems with one of its data servers. Sufficient spares are on hand to fix this. Scheduled for this afternoon.
PTCS -- PTCS Team
- Engineering
- Planning for ramping up efforts in anticipation of new staff.
- Astronomy/Pointing
- Pointing team is planning how to implement PFM version 5. To support future generality, we are considering revising the organization of how the pointing model is stored in the database and calculated in the antenna manager. Will meet later today.
- Work continues on the holography simulation project note. We are also beginning to outline the lab tests that will need to be done when reviving the holography receiver and backend.
MIT/LL 43m Project -- Glen
Normal spacecraft tracking except on Tuesday when we had a brake spring failure. Preston, the antenna mechanics and machine shop all pitched in and we were able to get back into operations by 7:00 PM. Tracking was scheduled to start at 4:00 PM.
The MIT/LL folks are planning a test with Haystack on June 13. They are also planning on switching to the high frequency feed later in the summer. During that time they want to ship the low frequency feed back to MIT/LL.
-- RichardPrestage - 07 Jun 2007
Revision r1.11 - 08 Jun 2007 - 15:20 GMT - RichardPrestage
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