GBT Operations and Commissioning Meeting 20 February 2004 AGENDA 1. Az Track and Telescope Status -- Bob 2. Observing News -- Ron 3. Holography Results -- Richard, Ron, Fred S. 4. Frontends, IFs, and Spectral Baselines -- Roger 5. Spectrometer Status -- Rich 6. Software Status -- Amy 7. Scheduling Status -- Carl 8. Project Planning Status -- John 9. Any other Business PRELIMINARY REPORTS 1. Az Track and Telescope Status Az Track * A previously known crack in Plate 35 has expanded to the top surface. It is being monitored daily, and will be replaced soon. * No update from SGH as of this writing. Still expecting results in the next few weeks. -- RAA 2. Observing News This week we saw about half a dozen projects, 2 sessions of project checkouts, and 1 session for some rather successful holography and active surface tests. We can discuss the holography results at the end, if time allows. About 8% of the 150 hours scheduled for observing or tests was lost. There was no time loss this week directly due to the weather. Over 8 hours was lost due to a hardware problem with the telescope's e-stops, probably a belated byproduct of the ice storm. 1 hour was lost to an antenna manager problem Thursday evening, 1 hour to crashes to a significant fraction of M&C last Friday evening, and 1 to 2 hours to the usual Spectrometer failures. We'll be gearing up for Q-band tests, which resume on March 1. -- RJM 3. Holography Results 4. Frontends, IFs, and Spectral Baselines Baselines: The Q-band receiver was installed on the GBT on Tuesday. A few hours of tests run Thursday afternoon showed reasonably good performance. The extremely large baseline ripples seen in January were absent, probably due to the work done in the lab over the past two weeks. However, there are still effects present that will limit spectral sensitivity. Ka-band and mmConverter: RF testing of the breadboarded mmConverter is underway, and fabrication of filters and amplifiers for this system continues. The 7-14GHz preselection filters have been completed, and the first article of the 13-20GHz is completed. Packaging layout is underway. The fourth cryogenic 26-40GHz LNA has been repaired by the CDL, and installed in the receiver. The 300K RF assembly continues to come together. Assembly of the first article detector amplifiers should begin next week. Other: Several engineers spent Wednesday visiting the new technical center in Charlottesville, and in discussions with staff there. -- RDN 2/20/2004 5. Spectrometer Status *****Operation***** This week the spectrometer exeperienced its usual occasional problems with DMA errors. In addition it experienced a problem with the "obs" self test which cost a bit of check out time. Thanks to the SDD for alerting me to this problem in a timely way! Stangely, there was no hardware problem associated with this failure; it was "fixed" by running the "self test with polling." *****Development***** Work on the LTA card upgrade continued. In particular, timing simulations for the Xilinx chips continued. The simulations are nearing completion but it is hard to predict an end date due to the unknown amount of time it takes to fix errors as they are found. Code written for spigot card testing is being cleaned up and archived. A formal test procedure for the spigot cards is being written. *****Plans for next week***** Upgrade the two spigot cards in the system with the new firmware. Bench and system test all the cards. Finish the test procedure for the spigot cards. Continue development of the cross-correlation test fixture. In particular complete the design of the noise sources. Continue work on the LTA upgrade. -- Rich and Holly 6. Software Status Single Dish Development IPT #70 - Friday, February 20, 2004 This week begins the new development cycle, C2 in 2004. The Plan of Record will be available shortly from the wiki at Software.PlanOfRecordC22004. C1 culminated with the release of M&Cv4.1 on Tuesday afternoon; release documentation for M&Cv4.1 is at Software.SoftwareReportCentral on the wiki. New functionality is also under development as part of the Observing API. This week, Mark and Amy added cosV corrections, and will create a new iteration of observing procedures next week. Frank has also been testing out how the new API can be used to write user-defined procedures more easily. Extensive testing on the ported Converter Rack and GPIB server has commenced this week. This will continue next week, and maintenance activities will be launched as several code reviews take place (Ka/Common MM/SDFITS/Grail). SDD operational support this week included: + Support for code management of Claire Chandler's holography updates + Addition of spectrometer modes to handle special low-frequency + configurations, under the guidance of Glen and Frank Participation in + CCB meetings Support for Zernike polynomial experiments which were + very successful -- NMR 7. Scheduling Status Last Week ========= Observations for proposals GBT03C-009, GBT01A-061, GBT01A-054, GBT01A-058, GBT03B-027, GBT02B-016 Completed proposals GBT01A-054, GBT03B-027 Next Week ========= Observations scheduled for GBT01A-061 PI Wendy Lane A blind search for redshifted HI 21cm Absorption GBT02A-063 [P] PI Mark Claussen Water Maser Monitoring of Low and Intermediate Mass Young Stellar Objects GBT02A-031 [B] PI Jay Lockman Galactic HI Mapping of X-Ray, UV, and Optical Deep Fields GBT02A-046 [P] PI James Braatz Monitoring a Maser Disk in Mrk 1419 GBT03B-013 [B] PI Min Yun An Unbiased HI Survey of the Coma Cluster and Beyond GG053 PI Michael Garrett High resolution radio observations of the Hubble Deep Field Region. GBT02A-025 [P] PI Mike Hollis A Search for the Next Interstellar Aldehyde Sugar: Glyceraldehyde GBT03A-015 PI Wendy Lane A Search for 21cm Absorption in High Redshift Damped Lyman-Alpha Absorbers GBT03B-015 [B] PI Scott Ransom Timing the Pulsars in the Globular Cluster M30 GBT03A-016 [B] PI Ingrid Stairs The Physics of a Massive Pulsar System GBT03A-006 PI Phillip Kronberg Proposal to search for diffuse low frequency synchrotron-radiating extensions of the Coma Cluster February ======== Scheduled hours [backup] Astronomy ~ 386 [86] Maintenance ~ 59 [35] Tests & Comm ~ 247 [31] Un-assigned ~ 5 March ===== Scheduled hours [backup] Astronomy ~ 484 [227] Maintenance ~ 2 [157] Tests & Comm ~ 251 [69] Un-assigned ~ 8 April ===== Scheduled hours [backup] Astronomy ~ 59 Maintenance ~ [149] Tests & Comm ~ 101 Un-assigned ~ 560 Proposal Checkouts ================== Awaiting checkout - 0 Active checkout - 30 On Hold - 7 Schedule - 44 Completed - 147 Current backlog [hours] = 2792 -- RCB 8. Project Planning Status February 17, 2004 Planning Meeting Minutes Rm 137 10:00 A.M. [0] Observer comments & operator log items to discuss Langston: Brett Little and Frank Briggs, 01A58 Summary: Setup extremely painful due to a series of troubles, followed by eventual smooth operations. RFI significant in this band, perhaps slightly worse than previous observations, but cause uncertain. February 12/13 2004 Observing startup much smoother through use of CLEO tcf from previous run. Spectrometer Data Interrupt Problem occurred at start. Otherwise few problems. Project: AGBT03B_027_05 Observers: H. Butner Hardware: K-band, spectrometer Support: T. Minter Dates: Feb 11 7:15-18:00 Problem summary: ================ 1) spectrometer did not get setup properly 2) intermittent spectrometer balancing problem Projects: 3C9 Observers: J. Darling Hardware: 350 MHz, spectrometer Support: T. Minter Dates: Feb 15 14:00-24:00 Problem summary: ================ 1) config_tool: PF1 20 MHz filter was known to be broken but was selected. (Toney asks the excellent question as to who should put broken devices in the baddevices.conf file) We discussed the problem Toney reported about the filter being selected, even though it is known to be faulty. The system treats the fillter assembly as one unit, and does not allow for a section of it to be flagged as bad, while the rest of the filter assembly is used. It will be looked at to see if this capability should be added. ** Action Item: In the meantime, a comment will be added to ** the devicehealth file to note that the particular filter ** is bad. Galen Watts and Melinda Mello will be charged ** with keeping this file up to date. Roger Norrod will ** decide if a device needs to be put in that file. Frank Ghigo, Project Checkout: On Sunday morning, Feb 15th, data was collected for several projects. 1. For projects 03B_028 and 03C_002, collected data for estimating sensitivity of wide-band continuum observing at K-band. 2. For project 04A_041, a radar observation of Mercury, checked the visibility of a source at low elevation (6-7 degrees) in the west. 3. For VLBI projects, collected data for determining Tcals for circular polarization observing in S and L bands. In general everthing ran very smoothly. Setups with the config_tool for the various different projects worked well. I used GO_LITE and the new GFM. This worked fine for pointing and focus, but its spectral line display is too primitive. Feb 16, 2004 11:58 AM Observer or Visitor Jeremy Darling Reason for visit Observing Proposal codes GBT03C-009 Summary: Observing proceeded without a hitch, setup was fast, and the help was (as usual) excellent. The spectrometer behaved itself for the most part, but I did find bad records in my data (3-sec samples). I only found about 1 bad record per few hours, which is a big improvement from previous runs. Description of RFI environment The RFI environment was moderate. There was plenty of RFI in the observed bands, but in only one band was there a very strong signal that affected the balancing. Note that the active surface motors (?) were not turned off until the latter third of the session, and it may be worthwhile to see if the previous shielding work paid off (AGBT03C_009_08). Hardware None. Most of the spectrometer problems seem to have been fixed. Software It would be nice to be able to set up an observing script that can rebalance the IF rack, etc without aborting scans. Services Observing support was excellent, both from my \"friend\" and the operators. [1] Resource calendar schedule conflicts and discussions Is Friday a Maintenance day? It was not clear from the schedule when the maintenance day was. It is Friday, after all the dynamic scheduling smoke cleared. [2] Observing Schedule discussions Carl is having problems finding enough backup projects to fill certain LST ranges and days in March. It seems to be a problem of not enough LF proposals. Some other problems that exacerbate this are PF feed changes, and the need for the TAC to look at LST range competition for LF proposals. ** Action item: Carl will research this and present his findings ** at next monday's meeting as to how we can ease this problem. [3] GBT development planning GBT interlock system The interlock system on the GBT is extremely hard to troubleshoot. In the case of multiple faults, there is no way to tell if one caused the other. We need to plan to replace this system with a system based on a PLC that can be programmed to deliver the information that we need to be able to troubleshoot the system. In addition, the wiring needs to be rearranged to allow for adequate isolation of sections of the wiring, so that one short or broken wire does not shut down all the fault sensing circuits. [4] AOB Nicole and John will get together on a new instruction sheet for the spectrometer. It seems that there are conflicting instructions floating around. -- JF 9. Any other Business