GBT Operations & Commissioning Meeting
AGENDA
- Harry and John have everything ready for our upcoming surveying efforts. We all practiced this yesterday. General Dynamics will be here next week as well.
- Structural inspectors found a defect dead center under the receiver room. Unanimous opinion is that the weld quality caused this - it is in a low stress point. It does need to be fixed, and we and M&M are making preparations, and planning to do it the week of August 7.
- An event at the 43 meter telescope resulted in an oil leak and lost time. The failure was caused by a combination of work procedure and logic errors, and initiated by two switches giving false indication that the brakes were released. Actions have been implemented to prevent recurrence, and the telescope was placed back in service.
We supported 15 projects in 24 observing sessions, including a VLB run. Average setup time was 13 minutes. The telescope was also scheduled for 42 hrs of maintenance and 6 hrs of calibration tests.
Lost time was 2.75 hrs, just above 2% of the time scheduled for observing and tests. Of the 14 operator shifts, only 7 had any lost time. The causes of lost time were rather "typical":
- Spectrometer (6 incidences) -- 1.5 hrs
- Spectral Processor (4 incidences) -- 0.5 hrs
- Astrid (2 incidences + 1 NLT) -- 0.5 hrs
- Weather (1 incidence + 1 NLT) -- 0.3 hrs
- Other NLT problems -- Weather 1 and Titania
Titania has been replaced in case some of our recent problems were hardware related. The high number of spectrometer and spectral processor problems is related to polarization experiments that stress the backends.
In other news
- Scott was unable to reproduce the 'RFI/Rsync' problem reported a few weeks ago.
- Frank tested the modified Converter Module, a topic from last week's meeting. All of us who have looked over Frank's results agree that the new modules handle power levels better than the old with fewer instances when the system won't be able to balance. We also know that the revised design will not have enough range of attenuation in some cases, but the number of such cases is fewer than the old design.
- Shelly Hynes, Charles Figura, and I will give a technical seminar on Thursday on our interesting results from the last few calibration runs.
Last Week
=========
Observations for proposals
GBT06B-030, GBT06B-031, GBT06B-032,
GBT06B-044, GBT06B-033, BU031 ,
GBT06A-046, GBT02A-053, GBT06B-045,
GBT06B-035, GBT06B-026, GBT06B-038,
GBT06B-006, GBT06A-070, GBT06A-072
Completed proposals
GBT06B-031, GBT06B-045
Next Week
=========
Observations scheduled for **
GBT06B-030 [F ] Peter Martin
Characterizing Dust Evolution in Intermediate
Velocity Clouds
GBT06B-020 [F ] Karen O'Neil
HI in Galaxies and Environments
GBT06B-053 [F ] Min Yun
Completing the GBT Survey of Cold Diffuse
Intragroup Medium in HCGs
GBT05B-042 [F ] Michael Kramer
Timing and General Relativity in the Double
Pulsar System
GBT06B-012 [ B] Loris Magnani
OH Observations of the Envelope of MBM 40
GBT05B-034 [F ] Ingrid Stairs
Timing Binary and Millisecond Pulsars from the
Parkes Multibeam Survey
GBT06B-026 [F ] Julia Deneva
Searching for Pulsars and Transient Sources in
the Galactic Center
GBT06B-038 [F ] Dick Crutcher
Magnetic Fields in GLIMPSE Dark Filaments
GBT06B-016 [FP ] Sandra Bruenken
A Search for the Nucleobase Uracil towards
Sagittarius B2
GBT06B-006 [F ] Carl Gottlieb
Search for Four C5H2 Carbene Molecules in Space
GBT06B-019 [F B] Toney Minter
Obtaining A Complete Sample Of Pulsar OH
Absorption With The GBT
GBT06A-071 [F ] Fernando Camilo
Constraining the distance to the magnetar XTE
J1810-197 via HI absorption
** Scheduled as F-ixed, P-rimary, B-ackup
Contact Information for 08/03/2006 - 08/17/2006
=======================================
Proposal PI Bands Email [NRAO contact]
---------- ------------------ ----- --------------------
GBT06B-040 Nissim Kanekar U nkanekar@nrao.edu [Scott Ransom]
GBT06A-053 Scott Ransom S sransom@nrao.edu [Scott Ransom]
GBT06B-052 Min Yun L myun@astro.umass.edu []
GBT06B-030 Peter Martin L pgmartin@cita.utoronto.ca [Jay Lockman]
GBT06B-020 Karen O'Neil L koneil@nrao.edu [Karen O'Neil]
GBT06A-054 Paul Demorest L demorest@astron.berkeley.edu [Scott Ransom]
GBT06B-032 Steve Begin S sbegin@physics.ubc.ca [Scott Ransom]
GBT06B-021 Karen Masters L kmasters@cfa.harvard.edu [Frank Ghigo]
GBT06B-033 Jason Hessels 8 hessels@physics.mcgill.ca [Scott Ransom]
GBT05C-042 Scott Ransom S sransom@nrao.edu [Scott Ransom]
BK127 Kirsten Knudsen L knudsen@mpia-hd.mpg.de []
GBT06B-034 Jacqueline van Gor L jvangork@astro.columbia.edu [Frank Ghigo]
GBT02A-053 Carl Heiles LS cheiles@astron.berkeley.edu []
BU031 Jim Ulvestad S julvesta@nrao.edu []
GBT06A-046 Glen Langston U glangsto@nrao.edu [Glen Langston]
GBT06A-013 Jim Braatz U jbraatz@nrao.edu [Jim Braatz]
GBT06B-012 Loris Magnani L loris@physast.uga.edu [Ron Maddalena]
GBT06A-014 Andrea Tarchi K atarchi@ira.cnr.it [Jim Braatz]
GBT06B-013 Tyler Foster C Tyler.Foster@nrc-cnrc.gc.ca [Dana Balser]
GBT06B-014 Paulo Freire S pfreire@naic.edu [Scott Ransom]
GBT06A-004 Bill Reach K reach@ipac.caltech.edu [Toney Minter]
GBT05C-046 Ingrid Stairs L istairs@astro.ubc.ca [Scott Ransom]
GBT06B-026 Julia Deneva XC deneva@astro.cornell.edu [Scott Ransom]
GBT06B-028 Ingrid Stairs L istairs@astro.ubc.ca [Scott Ransom]
GBT06A-070 Fernando Camilo CUSX8 fernando@astro.columbia.edu [Scott Ransom]
GBT06B-009 Joe Helmboldt L helmbold@unm.edu [Larry Morgan]
GBT06A-072 Vicky Kaspi S vkaspi@physics.mcgill.ca []
Scheduled hours [backup]
========================
Category/Month-> July August September
Astronomy ~ 510 [045] 413 [061] 449 [282]
Maintenance ~ 145 199 40 [068]
Test & Comm ~ 90 [009] 102 [005] 148 [021]
Un-assigned ~ 0 30 87
Proposal Checkouts
==================
Awaiting checkout - 0
Active checkout - 0
On Hold - 20
Schedule - 63
Completed - 517
Current backlog [hours prior to 06B*] = 1025
[2001:2(1), 2002:3(1), 2003:19(1), 2004:107(7), 2005:544(23), 2006:350(18)]
Backlog excluding 139 hrs of monitoring projects after 06B = 886
Total time to discharge [hours] = 2324
Includes 419 hours of monitoring after trimester 06B
* Includes projects that are on hold for trimester 06B
No problems this week.
High Frequency Receivers:
Q-band Receiver:
Work on upgrading the 300K RF plate to bring the bandwidth up to spec began this week. Baseline testing continues using the test dewar. A pair of the cryo LNA's which were in the system on the telescope last winter have been sent to CDL for examination.
Ka Receiver:
The card cage modifications are mostly complete, we're waiting on some
brackets currently in the shop que to finish. Tracy has started
building the room temperature plate portion, modified so the
differencing loops no longer will need to be broken to install the
receiver on the telescope. Some receiver frame modifications for the
new configuration have been completed, more are expected. Circuit
boards for cal control and switching by the Zpectrometer are designed
and fabrication files are being prepared.
Digital Group Status 15-JUL-06 THRU 21-JUL-06
***Operations, Problem Summary***
1) The Spectrometer exhibited its "DMA Hangup" problem again Sunday evening. Mark Clark was able to return things to normal
by going through a complete power-down cold restart. The problem hasn't recurred since then.
2) Weather Station #1 was damaged by lightning Tuesday afternoon. Temperature, pressure, and humidity functions have been restored,
but wind speed and direction functions will be down until further notice.
***Development***
Caltech Continuum Backend (CCB)...
Construction of CCB #3 is still underway with an expected completion date of 28-JUL-06.
Spectrometer LTA Re-design...
Work continues on the LTA re-design project... A detailed project schedule should be ready by 28-JUL-06.
Lab Spectrometer...
No change from last week's report.
ALMA...
Manasseh Obi continued his work on bias card noise analyses and measurements with input from John, Jason, and Randy.
***Plans***
- Continue Active Surface maintenance...
- Continue construction of CCB #3...
- Continue work on LTA re-design and prepare project schedule...
- Continue ALMA support as needed...
Randy
This ends Week 3 of 6 in the fifth development cycle of 2006 which can be viewed at PlanOfRecordC52006. We will not be releasing at the end of this cycle. Instead, we plan to patch MRs in as they are completed and sponsor tested in system.
MelindaMello and PaulMarganian are visiting the JCMT to gather information on their dynamic scheduling system. We aim to learn as much from the JCMT as possible since they have both policy experience and working software.
We received a ColdFire development kit sent us by Andy Harris for the Zpectrometer microcontrollers. It has been unpacked, set-up and Ray is in training as to its operation. The next step is to obtain a network adapter, a Windows PC for development, and download the UMd firmware to the development kit.
We spent some time this week reviewing candidates for our open software position. Because the wiki is public, I will include no further details of our interview process in this report but we will be happy to answer any questions in person.
Operational support was light this week and included:
- Regarding the lock-ups being reported on titania - titania has not been rebooted since Wolfgang swapped out its hardware.
- Failure of ScanCoordinator values being passed to devices, e.g., sky positions or project IDs
- Repeated Spectrometer DMA errors - LTA board?
- Responded to report of antenna error messages. Traced to power being off.
- Responded to inquiry regarding Weather 1. Hardware was damaged from lightening.
Modification Requests:
- MRs ready for sponsor testing:
- MRs under development:
- MRs ready for CCC review:
- MRs being written:
Things are continuing to work well with the spigot except for a few strange Firewire incidents that have required a reboot or three. I tested running the spigot with various rsyncs going across both networks (including with the "bad" routing that was being used during Nissim's Ku-band observations). I used the same exact Ku-band setup and could not trigger the interference no matter what I tried. So the case is still open... any other ideas?
In the hot-off-the-presses section, Fernando (who is at IRAM now) and I just made solid detections over the past 2 days of the magnetar at 87GHz and 140GHz! The latter shatters the old record of a pathetic ~3-sigma detection of a pulsar at 87GHz with IRAM. You can see the plots here:
http://www.cv.nrao.edu/~sransom/IRAM_53935_87GHz_B_5540.54ms_Cand.pfd.ps
http://www.cv.nrao.edu/~sransom/IRAM_53936_140GHz_B_5540.55ms_Cand.pfd.ps
Too bad the GBT isn't working in the 50+ GHz range yet....
MIT/LL 43m Project -- Glen
-- RichardPrestage - 06 Jul 2006
Revision r1.8 - 27 Jul 2006 - 17:27 GMT - AmyShelton
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