GBT Operations & Commissioning Meeting
AGENDA
Activities List
Only two welds remain to be completed as of this morning, along with a section of base plate to splice plate welds. Next week will see final height adjustments at night, machining of the top surfaces, and forming for grout installation. We still expect to be able to permit pointing runs mid-August.
Brief summary of the checkout of S- and X-band receivers,
August 2-3, 2007. Frank, Jules, and Paul observing in Green Bank,
Scott in C-ville, with Barry and Greg operating.
No azimuth motion was possible, but we were allowed
to set the elevation to anything above 30 degrees.
The plan was to watch the transits of several calibration
sources from Condon's calibrator lists while collecting
spectral line data.
The first problem was that the database telling the antenna
which receiver was in which slot had not been updated, and
also that the cabling file, although it had been updated,
had not been re-loaded. Mark Clark came in and took care
of these details.
At X-band, we failed to see a source transit. Our predictions
of the correct elevation for transit seemed to be confirmed by
the antenna readback of the J2000 position, which was within
an arcminute of the correct declination. Nevertheless we never saw a
good transit after 4 attempts. Otherwise, the X-band receiver
seemed to be working ok as far as we could tell.
There was better luck at S-band; we did see sources transit.
The RFI from the XMM/Sirius satellites was visible in the
band. Observing a calibrator at narrow bands to avoid the
satellites showed about the right antenna temperature.
Scott checked spigot observing with the S-band receiver,
and reports that things seemed to be working.
The sharper bandpass cutoff at the lower end was apparent,
and he saw much reduced RFI.
Last Week
=========
Observations for proposals
GBT07B-012
Next Week
=========
Observations scheduled for **
GBT07B-012 [F B] Dunc Lorimer
Pulsar searching in the classroom using the GBT
GBT07B-035 [F ] Sue Ann Heatherly
WV Governor's School for Math and Science (GSMS)
** Scheduled as F-ixed, P-rimary, B-ackup
Contact Information for 08/16/2007 - 08/30/2007
=======================================
Proposal PI Bands Email [NRAO contact]
---------- ------------------ ----- --------------------
GBT07B-011 Dunc Lorimer 3 Duncan.Lorimer@mail.wvu.edu [Toney Minter]
GBT07B-012 Dunc Lorimer 3 Duncan.Lorimer@mail.wvu.edu [Toney Minter]
GBT07B-017 Vlad Kondratiev 3 vlad.kondratiev@mail.wvu.edu [Toney Minter]
GBT07B-006 Fernando Camilo S fernando@astro.columbia.edu [Toney Minter]
GBT07B-008 Nissim Kanekar 3 nkanekar@nrao.edu [Frank Ghigo]
GBT07A-060 Julia Deneva S deneva@astro.cornell.edu [Scott Ransom]
Scheduled hours [backup]
========================
Category/Month-> August September
Astronomy ~ 181 [323] 314 [376]
Maintenance ~ 189 21 [068]
Test & Comm ~ 374 322 [030]
Un-assigned ~ 0 93
Proposal Checkouts #[hrs]*
=========================
Awaiting checkout - 0[0]
Active checkout - 0[0]
On Hold - 0[0]
Schedule - 76[3221]
Completed - 491[6289]
* All but completed queue applies to GBT only proposals
Current backlog of Reg & RRS proposals [hours prior to 07B*] = 1170
[2005:369(14), 2006:358(18), 2007:444(21)]
Backlog includes 59 hrs of monitoring projects
182 hrs of vlbi projects
Total time to discharge [hours] = 5195
Includes 274 hours++ of monitoring (not Large or Spec) after trimester 07B
1646 hours of Regular & RRS proposals
3317 hours of Large proposals
50 hours of Track Refurbishment proposals
182 hours of VLBI proposals
* Includes projects that are on hold for trimester 07B
++ Time is counted in other break down as well. 07B
- S band installed as planned; ready for use.
- X band installed as planned; ready for use.
- Feed defroster: Anechoic chamber testing is scheduled for Monday Aug 6. Installation of blower scheduled for Tues Aug 7.
- Maryland contingent postponed Z spectrometer tests with Ka band for a week.
- Ka band is cooled with modifications ready for Z spectrometer tests.
- Bob Simon completed modification of a Zpectrometer Test Tone Doubler, bench tests show smoother frequency response.
- This doubler along with the noise cal sources installed on the receiver in time for CCB and Zpectrometer testing next week
- Mustang is scheduled for arrival Monday, August 6. Followed by two days of test dewar cryogenic tests. Receiver installation on Thursday.
None
LTA tests continue on the bench successfully.
Tests for the subreflector actuators will be attempted next week. It is suspected that they are not tracking commands properly.
Testing of PLC interlock system upgrade continues. PLC logic program being tested along with analog control board. Tests should complete next week. Software for interfacing the CCU with the PLC is being developed.
140ft network upgrade is complete. The link from the Jansky lab is now at 1Gbps instead of 100Mbps and a Cisco 3550 switch is in place.
Funds to upgrade the servo room switch have become available and a plans are being developed which will provide more network connections and a much faster switching fabric. If the parts can be delivered and configured in time I hope to get this installed by the end of August.
PTCS -- PTCS Team
Servo Systems: No progress
Pointing:
Joe is ready to test the new M&C pointing model implementation w.r.t.
Kim's model. I plan to have a pointing meeting mid-week of next week to
schedule these tests, and our plans for the track recovery observations.
Holography:
The vicinity of the optical camera mount should be an acceptable
location for the holography reference receiver, at least in terms of
opening angle w.r.t. the telescope structure. Steve has estimated the
length and cost for the necessary low-temperature coefficient IF cable,
and the loss in dB. Still need to work out the mechanical details, and a
surveying strategy to measure the position of the horn. Ron Grider
estimates that phase 1 of the Linux upgrade of the control software for
the backend will be complete in about 2 weeks.
Ran tests with the newly upgraded S-band receiver last night with the cold RFI filter. Test pulsars and pulsed cals looked just fine, as does the bandpass. I see no evidence of the nasty Iridium interference leaking through (and it was that interference that the new filter was intended to get rid of. The only bad thing is that is looks like we've lost about 60 MHz of usable BW. The plot below shows most all of what I've said graphically.
MIT/LL 43m Project -- Glen
- Troubles with 43m cyrogenics on Friday, which were quickly repaired.
- Normal Spacecraft tracking Tuesday through Friday
- Met with MIT/LL on July 31.
- Next years operations will be similar to last
- Are working on pointing tests to confirm spacecraft tracking interface.
- MIT/LL wants a new observing mode, allowing more rapid changes to spacecraft trajectories. We will write specification in next few weeks.
- MIT/LL will come to NRAO in August
- They are, in general, willing to support Lunar Neutrino experiment. Would like to discuss, with Rich Bradley, feed design options.
- Are very interested in ethernet upgrade to allow real-time data transfer.
- Frank Lind and Phil Erickson are writing papers on their experiments. They will continue with work in FY 08.
- July 17 through Aug 1 : L-Band refrigerator work. Must be completed for Governor's school
- Aug 1 through Aug 17 (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 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 17 (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.
- Aug 17 - Sept 1 (end of shutdown to 2 weeks later) : Contingency test time for any remaining S-, X-, and Q-band receiver checkouts. One nighttime 4 hr sessions per week. Dynamically scheduled.
- Aug 17 (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
- Week of Sept 10 : Install C-band (same location where Mustang was mounted).
- Sept 14 : End of PTCS recommissioning of track
- Week of Sept 17 or Sept 24 : Install Ka-band. Contingent on Aug 10 decision.
- Sept 17-30 : C-band astronomical commissioning, C-class weather (need to check this with Dana)
- 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 10 decision.
- Week of Sept 24 : Q-band project 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).
- 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 1-30 : C-band baseline tests, C weather, dynamically scheduled.
- Oct 1-30 : X-band baseline tests, B weather, dynamically scheduled.
- Oct 7 - 15 : CCB/Ka testing, A-class weather (nighttime, dynamically scheduled).
- 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.
- 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?
- 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 - 02 Aug 2007
Revision r1.11 - 03 Aug 2007 - 13:55 GMT - RonMaddalena
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