GBT Operations & Commissioning Meeting
AGENDA
Activities List
A very busy two weeks.
- Dennis and I went to Continental last week to observe final machining. We worked through several issues with them, and continue with that effort this week.
- I have received a quotation from Continental for splice plate refurbishment on site. We all believe this is the way to go. Mike and I need to finish this up and get a contract change in place to include it.
- I have a field schedule from Satcom, and will work on it when hotter issues are put to bed.
- We have received data from the measurements from the Gadsden template. We are in the process of looking at it. Further work needed.
- We received 10 plates last week during the EOS (Dennis and I passed the truck on our way to the airport - Savannah didn't have an EOS!). We expect 10 more next Wednesday, plus a transition plate.
- The mechanics replaced a cracked plate last week, and another one this week.
- The mechanics also made a further adjustment to the 45' balance this week.
We supported 19 projects in 33 observing sessions, somewhat busier than normal. The telescope was scheduled for 13.5 hrs of maintenance, 8 hrs of Ka-band commissioning (6 of which were scrubbed because of temperatures below zero), 1.5 hrs of receiver checkout, and 1 hr of project tests.
Weather again dominated our lost time. The other noticeable item was 2 motors that had to be shut down Friday night due to tachometer problems. Except for the time needed to diagnose the problem, we were able to run with these 2 motors off until the tachs were fixed on Tuesday. Here's a summary of the lost time:
- Observer Error (0.4 hrs, 0%)
- Observer no-show : 0.3 hrs
- Script problems : 0.1 hrs
- Weather (18.5 hrs, 12%)
- Temperatures < 0 F : 11.6 hrs
- Winds (6 instances) : 6.9 hrs
- Hardware/Software/Operational (3.7 hrs, 2.4%:
- Tachometers (2 instances) : 2.4 hrs
- Spectrometer (2 instances) : 0.4 hrs
- Astrid (2 instances) : 0.3 hrs
- GFM (2 instances) : 0.3 hrs
- Antenna Manager : 0.2 hrs
- Operator (wrong rcvr selected) : 0.2 hrs
- Cryo, VNC (2 instances) : No lost time
Last Week
=========
Observations for proposals
GBT07A-030, GBT07A-063, GBT07A-031,
GBT07A-020, GBT07A-098, GBT06C-052,
GBT07A-001, GBT06A-056, GBT06B-044,
GBT07A-036, GBT05C-043, GBT07A-104,
GBT06C-049, GBT05C-027, GBT06B-018,
GBT07A-050, GBT03C-028
Completed proposals
GBT07A-020, GBT06C-049
Next Week
=========
Observations scheduled for **
GBT07A-030 [ P ] Brian Mason
A Search for Polarized, Anomalous Microwave
Emission from Lynds 1622 - copy
GBT07A-063 [ PB] Amanda Kepley
Magnetic Fields in Irregular Galaxies
GBT07A-010 [ B] Bob Mutel
A Search for Narrow-Band Stellar Radio Bursts
Associated With CMI Emission
GBT07A-098 [F ] Fernando Camilo
Studying the magnetar XTE J1810-197
GBT06C-052 [ B] Scott Ransom
Continued Timing of the Binary and Millisecond
Pulsars in NGC6440 and NGC6441
GBT06A-054 [F B] Paul Demorest
Long-term Precision Timing of Millisecond Pulsars
GBT07A-034 [ P ] Jim Braatz
The Megamaser Cosmology Project: A Survey for H2O
Masers in SDSS and 2MRS AGNs
GBT06A-056 [ P ] Paul Kondratko
Are there Unrecognized NGC4258-like Systems Among
Known Water Masers in AGN?
GBT05C-043 [ P ] Nissim Kanekar
A blind GBT survey for redshifted molecular
absorption
GBT06C-045 [ B] David Champion
A Search for Radio Emission from Magnetars after
Outburst
GBT07A-015 [ PB] Jeff Mangum
Formaldehyde Densitometry of External Galaxies
BC162 [F ] Giuseppe Cimo
Two Dimensional Time Delay Measurement of
IntraDay Variable Sources
GBT07A-104 [ B] Peter Martin
The Spider's Web from Ursa Major to Polaris
GBT07A-039 [ B] Rick Fisher
Bulk Motions of Filaments in the Local Unverse
GBT04B-014 [ P ] Paul Kondratko
Anchoring the Extragalactic Distance Scale
GBT05C-017 [ P ] Anish Roshi
Direct Measurement of the Expansion of UCHII
Regions
GBT07A-050 [ P ] Claudia Cyganowski
Kinematics of Ionized and Molecular Gas
Associated with IR Dust Bubbles
** Scheduled as F-ixed, P-rimary, B-ackup
Contact Information for 03/08/2007 - 03/22/2007
=======================================
Proposal PI Bands Email [NRAO contact]
---------- ------------------ ----- --------------------
GBT07A-030 Brian Mason X bmason@nrao.edu [Brian Mason]
GBT07A-098 Fernando Camilo S fernando@astro.columbia.edu [Scott Ransom]
GBT06C-051 Lincoln Greenhill K greenhill@cfa.harvard.edu [Jim Braatz]
GBT07A-034 Jim Braatz K jbraatz@nrao.edu [Jim Braatz]
GBT07A-012 Mousumi Das K mousumi@rri.res.in [Larry Morgan]
GBT06B-043 Laurent Pagani K laurent.pagani@obspm.fr [Larry Morgan]
GBT07A-089 Fernando Camilo 8 fernando@astro.columbia.edu [Scott Ransom]
GBT06B-032 Steve Begin S sbegin@physics.ubc.ca [Scott Ransom]
GBT06B-044 Robert Ferdman L ferdman@phas.ubc.ca [Scott Ransom]
GBT06B-033 Jason Hessels 8 jhessels@science.uva.nl [Scott Ransom]
GBT05C-032 Yancy Shirley BQ yshirley@as.arizona.edu [Ron Maddalena]
GBT04C-031 Paul Kondratko K pkondratko@cfa.harvard.edu [Jim Braatz]
GBT07A-048 Larry Rudnick L larry@astro.umn.edu [Toney Minter]
GBT04A-001 Paul VandenBout Q pvandenb@nrao.edu [Ron Maddalena]
GBT07A-015 Jeff Mangum U jmangum@nrao.edu [Frank Ghigo]
GBT06B-014 Paulo Freire 3 pfreire@naic.edu [Scott Ransom]
GBT06C-003 Tony Remijan K aremijan@nrao.edu [Larry Morgan]
GT007 Greg Taylor L gbtaylor@unm.edu []
GBT06C-058 Gary Fuller KUX G.A.Fuller@manchester.ac.uk [Larry Morgan]
GBT07A-039 Rick Fisher L rfisher@nrao.edu [Frank Ghigo]
GBT06A-017 Jeremy Lim Q jlim@asiaa.sinica.edu.tw [Dana Balser]
GBT07A-019 Tom Maccarone 3 tjm@astro.soton.ac.uk [Scott Ransom]
GBT07A-080 Maura McLaughlin 3 maura.mclaughlin@mail.wvu.edu [Scott Ransom]
GBT06C-017 Miles Blanton U mcb39@physics.unc.edu [Frank Ghigo]
GBT05C-017 Anish Roshi B anish@rri.res.in [Dana Balser]
GBT06C-029 Sanjay Bhatnagar 3 sbhatnag@nrao.edu [Glen Langston]
GBT06C-018 Ingrid Stairs LS istairs@astro.ubc.ca [Scott Ransom]
GBT07A-093 Sanchayeeta Bortha L sanch@fcrao1.astro.umass.edu [Frank Ghigo]
GBT07A-072 Lisa Wei L hwei1@umd.edu [Frank Ghigo]
Scheduled hours [backup]
========================
Category/Month-> February March April
Astronomy ~ 564 [111] 631 [522] 586 [362]
Maintenance ~ 48 [009] 41 [059] 32 [051]
Test & Comm ~ 60 [008] 60 [025] 42 [008]
Shutdown ~ 0 0 17
Un-assigned ~ 0 14 44
Proposal Checkouts
==================
Awaiting checkout - 0
Active checkout - 0
On Hold - 14
Schedule - 93
Completed - 608
Current backlog [hours prior to 07A*] = 961
[2002:0(4), 2003:12(1), 2004:75(21), 2005:412(21), 2006:457(31), 2007:5(1)]
Backlog excluding 50 hrs of monitoring projects after 07A = 910
Total time to discharge [hours] = 3050
Includes 108 hours of monitoring after trimester 07A
* Includes projects that are on hold for trimester 07A
S-band refrigerator replaced; the unit had been operating for 17 months.
Maintenance day tests to investigate a reported instability in one L-band
receiver channel continued, but no obvious hardware problems were found. Will pursue more next week.
Design work continues for the C-band integrated receiver package. The PCBs
have been received. Fabrication of the housings continue. Some preliminary assembly and testing is underway.
Good progress has been made in understanding the source of the short-period baseline instabilities that plagued the Q and Ka receivers. A technical talk has been scheduled for next week to discuss the results.
Digital Group Status 17-FEB-07 THRU 23-FEB-07
***Operations, Problem Summary***
Last Friday, Barry Sharp reported a block of 64 actuators had gone down during the day. The observing schedule was tweaked to give Jason and J.D. a one hour time slot to fix an LVDT module; thus bringing the 64 actuators back on line.
Active Surface Maintenance...
(See above...)
***Development***
Spectrometer LTA Re-design...
The design and layout of the FPGA Adapter PCBA is now complete and all design and CAM files have been zipped up and uploaded to Imagineering for a quote. Owing to an unusual internal layer stackup in the design, their CAM department has requested a couple more days to finish the quote which should be forthcoming early next week.
New Pulsar Backend...
The Cincinnati team has now begun to make progress on the actual application. Ron DuPlain? reports that they should be ready for a "virtual demo" using a VNC setup between GB and UC by 02-MAR-07. Following this, they expect to conduct a face-to-face demo here at GB on or about 20-MAR-07.
Miscellaneous...
Jason and J.D. are working with Bob Simon to come up with a "soft start" scheme for the feed defrosters in an effort to aleviate recurring "blown fuse" issues.
ALMA...
On-going efforts are continuing fairly smoothly on the ALMA front.
***Plans***
- Place an order with Imagineering for LTA FPGA Adapter PCB's once quote is received...
- Order parts for LTA FPGA Adapter PCBA's...
- Continue to explore a "soft start" scheme for the feed defrosters...
- Continue ALMA efforts as required...
Randy
We are in week one of the second development cycle of 2007 which can be viewed at PlanOfRecordC22007. Our next release is scheduled on 28 March 2007.
MarkClark, RamonCreager, and MikeMcCarty are attending PyCon 2007 in Addison, Texas this week and part of next.
Operational and user support was relatively light this week and included:
- Assisted with a servo failure recovery.
- Investigated a report of a Scheduling Block hangup. The SB execution process (turtle.d) missed a state transition. It turns out that the online filler missed this transition as well, which points to a Grail hiccup.
Modification Requests:
- MRs ready for integration/regression testing:
- MRs ready for sponsor testing:
- Develop New Pointing Pre-Processing Application (ModificationRequest5C706)
- Undergoing sponsor testing. Continued analysis of results in comparison to results from similar glish code. Writing PTCS Project Note summarizing findings related to Focus scan processing that are now embodied in current version of Prepoint application.
- Extract Sampler Information from Log Files & Create Antenna Characterization Database (ModificationRequest3C107)
- Undergoing sponsor testing.
- MRs under development:
- 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:
- Fix Inclinometer Data Collection Problems (ModificationRequest1C207)
- We are working on an investigation and placing the results into the MR. We plan to discuss our findings thus far at the 22 Feb PTCS meeting.
- Other Activities:
- Dynamic Scheduling - Amy and Paul are working on a requirements document. Paul and Mike described opportunities for common ground between BOS and DSS. Jim Condon completed his memo entitled "Scientific Requirements for Dynamic Scheduling".
- Complete Pointing Processing Description Memo - No progress
- Complete Documentation of Cross-Polarization Changes - In progress
- Evaluate GBT Data Handling Status & Future Options - In progress
- GBT data. A start has been made on mirroring the GBT data to CV.
- Solaris workstation shutdowns: The public workstations pollux and titan will be shutdown permanently as part of the office space reshuffle.
- Receiver room laptop is to be upgraded.
- The SDLT drive used for taping gbt data and pulsar data has died. Still under warranty and a replacement will be arriving shortly. An SDLT6000 unit has also been ordered.
PTCS Developments -- John, Todd
Servo work
- No new developments or tests this week, as staff are either on travel or busy with other tasks
Progress toward a new pointing model
- The pointing team met on Thursday for 2 hours reviewing status of efforts and near-term plans.
- The log_collator utility is now being tested by users. The servo analysis plots shown last week were regenerated using this utility and show results consistent to within expectations. Another comparison test will be done with a dataset constructed independently by Kim.
- Joe plans to put in a fix to the inclinometer manager to fix the non-monotonic timestamps (which currently hamper Kim's development of a dynamical estimate of track effects on pointing). This should be in place in time for this weekend's pointing run. Another change will be made to prevents NaNs from appearing in the timestamp value.
- Current goal is to have inclinometer datastream clean in time for the March 7/9th pointing run.
Other items
- We have a pointing run this weekend, and plan to take pointing scans at different rates, 100"/sec or more, to test for whether encoder latency is a contributor to the pointing hysteresis.
- Frank and Todd have asked Brian Mason for some analysis software scripts for continuum maps obtained recently for PTCS purposes. He is looking at RALongMaps and daisy petal maps.
Rich Lacasse, Randy, my student Ryan, and myself made (we think) very significant progress on getting the 2048-lag 8-bit spigot modes working. We think that we've found that the spigot outputs data in a slightly different order than is specified by the design documentation. If this is correct, there will still be a calibration problem, but it will be much easier to fix that without the re-ordering problem being present. We should be able to re-order 8-bit data that we took on the original MSP to test whether this is correct. I'll be working on this today. We also have plans to attempt some further hardware tests either next week, or soon thereafter.
MIT/LL 43m Project -- Glen
- Week of fairly normal spacecraft tracking.
- MIT/LL Group hopes to return to GB the week of March 9
- A weld crack is being examined.
Our tests last weekend were 'frozen' out. Are there any generous souls wishing to donate 6 hrs of telescope time? Until (and if) we can get more telescope time, we're spending our efforts using the new calibration algorithm on data we took last fall.
We also had a 2 hr run on Tuesday that allowed us to do a band scan across all of Ka-band. The band scans we took last fall, which used a single diode, suggested that the receiver was inoperable above ~36 GHz. We are guessing that the diode we used puts out negligible power above 36 GHz. Tuesday's tests used both diodes and, in contrast, suggests that we have reasonable receiver response above 36 GHz. However, the frequency structure in Tsys in all channels is impressively large for frequencies above ~34 GHz.
Until now, we've not had any Tcal values for Ka-band. Galen's hot-cold tests were not able to produce reasonable values and our band scans from last fall were plagued by the weak diode problem. Tuesday's observations have provided us with our first preliminary values for Tcal.
-- RichardPrestage - 01 Feb 2007
Revision r1.14 - 23 Feb 2007 - 19:51 GMT - ChrisClark
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