GBT Operations and Commissioning Meeting 30 January 2004 AGENDA 1. Az Track and Telescope Status -- Bob 2. Observing News -- Ron 3. Frontends, IFs, and Spectral Baselines -- Roger 4. Spectrometer Status -- Rich 5. Software Status -- Amy 6. Scheduling Status -- Carl 7. Project Planning Status -- John 8. Any other Business PRELIMINARY REPORTS 1. Az Track and Telescope Status Az Track * Work continues on computer models at SG&H. No new results yet. * Splice 17 re-shimmed this week. Tilts to be run Friday morning. Structural repairs * Work continues today on walkway, weather permitting. * We received Peter Keating's report on the elevation shaft defects. He continues his assessment that the defects found were manufacturing defects, and recommends repair. We will update our plan and pick up this summer where we left off during the fall. -- RAA 2. Observing News We serviced ten proposals this week, a few of which were hurt with lost time. The main culprits were weather related (5 hours for winds, 5 hours for snow, 4 hours for low temperatures) and Spectrometer (6 hours plus about ten instances of problems that lasted under ten minutes). Of the 150 or so hours scheduled for observing or tests, 9% was lost to the weather and 7% to problems. -- RNM 3. Frontends, IFs, and Spectral Baselines 26-40GHz Rx (from Galen): The turret plate and frame are finished, the dewar, card cage and 300K box are being attached to them. Initial tests have been performed demonstrating that the phase switching is functional. A Y-factor test was performed and indicates an eventual T-receiver of less than 40K. The CCBE detector video amplifier design has been finalized, circuit board layout and parts acquisition have begun. Enough standard GBT voltage to frequency converters to perform on-telescope tests with the DCR are available. CDL cryogenic LNA repair of one amplifier and plating of amplifier bodies are awaiting completion of their move. Baselines: Concentrated effort for the past week on the Q-band receiver baseline issues has shown that the major problem originates in the dewar. The symptoms point toward fluctuations of the receiver noise, with roughly 20-40MHz frequency structure, with amplitude between a few tenths of a kelvin and a few kelvin, over time periods of 10 seconds or faster. The receiver will be removed from the GBT and brought to the lab for further investigation. -- RDN 1/29/2004 4. Spectrometer Status *****Operational status***** Some time was lost this week due to software problems. These are being addressed by the SDD who will report on them. The spare spigot board is still not working despite a lot of effort over the past 5 weeks. This week Holly spent two and half days in investigating big steps in scans. With the help of Frank and several astronomers, she found that all bad integrations happened in either 200 MHZ modes, or low speed 9-level modes. So far, it is not sure that no big steps reported in low speed 3-level modes is because these modes have not been used recently or there is indeed no big steps. We probably need to do some test in these modes to find out. As the data processing in 200MHZ and low speed 9-level are very different with low speed 3-level, and all modes use same hardware of the spectrometer, if that low speed 3-level modes have no bad integrations as 200 MHZ and low speed 9-level have is true, it would be very worthwhile to look through the relevant software codes. Langston has noted that recently the 1024-lag long steps have disappeared. No hardware has changed in the system except the following: A fair number of cards were shuffled around a few weeks ago looking for a problem (turned out to be the self-test would not pass without the spigot card inserted). The cards were all returned to their original slots. Makes one wonder about a contact problem?? Next time we have the problem we may want to power down, unplug and replug cards in the offending quadrant. *****Development efforts***** No work on cross-correlation test fixture. Continue working on FPGA simulating in the rest of the week. *****Plans for next week***** Continue work on broken spigot card. Continue work on LTA replacement. -- Rich and Holly 5. Software Status Single Dish Development IPT #67 - Friday, January 30, 2004 Today ends week 4 of 6 in the current development cycle. The Plan of Record is available from the wiki at Software.PlanOfRecordC12004 along with the most up-to-date status information. For ease of use and data analysis, the new beta data display is being integrated with a generic plotting and flagging tool; work on this is complete. All PTCS items (not dropped via SDD-sponsor agreement from this cycle) are on schedule and we are addressing bugs in GFM as they are identified and reported. An MR generated from the prototype generic DCR plugin is written and is currently pending sponsor approval; work on the production plugin will commence on the upon MR approval. Analysis is also underway for reengineering DISH, so that it can be used more interoperably. The analysis is expected to be complete by 2/15. Work on the active surface zernike polynomial coefficients has been tentatively marked as complete and is currently awaiting verification from members of the PTCS scientific staff. The occasional glish/tk/pgplot crashes which have been seen in Green Bank the last couple of weeks have been associated, apparently, with an out-of-date pgplot library. We believe the problem has been fixed. This problem was affecting offline data reduction and it may also have been responsible for some of the reported GO and IARDS crashes that have been reported recently. By Friday, January 30, the patch will be in place on all computers, and all AIPS++ installations. Many thanks to Bob Garwoord and Darrell Schiebel as they did most of the work to fix it. The SDD provided a large amount of operational support this week, which included: + Investigating and fixing the source of the GO table looping problem. The patch to correct the looping problem is expected to be tested and patched into M&C v3.19 on Friday, January 30. + Implementing changes to GO to support the use of user-defined coordinate systems, via the "asteriod.tbl" file. These changes were patched into M&C v3.19 earlier this week. + Investigating and fixing the source of the Abort failures on the Spectrometer (the software had to be restarted after an abort). The patch to correct the looping problem and been tested. And will be patched into M&C v3.19 on Friday, January 30. Investigation on the earth reboot issue continues. + Fixing the DCR "missed start tick" problem. This fix was patched into M&C v3.19 ealier this week and no further problems have been reported. + Increasing Grail's robustness. + Adding knowledge of Bryan Jacoby's backend and the MIT backend to the IFManager, which enables them to be added to the cabling file. These changes are scheduled for testing and patching into M&C v3.19 on Friday, January 30. Additionally, the configuration tool will also be patched to allow configuration of the system when using the *MIT backend*. -- AS 6. Scheduling Status Last Week ========= Observations for proposals GBT02C-008, GBT02A-063, GBT02A-065, GBT02C-030, GBT02C-020, GBT03A-023, GBT02C-054, GBT02A-046, GBT03B-026, GBT03C-006 Completed proposals GBT02C-008, GBT02A-065, GBT02C-020, GBT03A-023, GBT03C-006 Next Week ========= Observations scheduled for GBT03B-030 [B] PI Robert Benjamin High Velocity Clouds Interacting with the Milky Way? GBT02A-063 [P] PI Mark Claussen Water Maser Monitoring of Low and Intermediate Mass Young Stellar Objects GBT03C-031 [B] PI Bryan Jacoby Timing the pulsars in M62, NGC 6544, and NGC 6624 and Search for Ultra-fast pulsars GBT02C-020 [B] PI Chris Henkel A 6 GHz Survey of Extra-galactic OH Megamasers GBT02C-054 [P] PI James Braatz Measuring Nuclear Disks in NGC 1386 and IC 2560 (H2O) GBT03B-013 [B] PI Min Yun An Unbiased HI Survey of the Coma Cluster and Beyond GBT02A-046 [P] PI James Braatz Monitoring a Maser Disk in Mrk 1419 GBT03C-012 [P] PI James Braatz Follow-Up Observations of Extragalactic H2O Masers Discovered with the GBT GBT02A-028 [B] PI James Braatz Exploring the Radio Spectrum of Orion A and W51 GBT02B-016 [P] PI Philip Solomon Dense Molecular Gas and Star Formation in the High Redshift Universe (HCN) January ======= Scheduled hours [backup] Astronomy ~ 516 [17] Maintenance ~ 71 Tests & Comm ~ 157 [3] February ======== Scheduled hours [backup] Astronomy ~ 394 [243] Maintenance ~ [141] Tests & Comm ~ 301 [32] Un-assigned ~ 2 March ===== Scheduled hours [backup] Astronomy ~ 203 Maintenance ~ 2 [159] Tests & Comm ~ 87 Un-assigned ~ 452 Proposal Checkouts ================== Awaiting checkout - 0 Active checkout - 41 On Hold - 7 Schedule - 39 Completed - 141 Current backlog [hours] = 2970 -- RCB 7. Project Planning Status January 26, 2004 Planning Meeting Minutes Rm 137 10:00 A.M. [0] Observer comments & operator log items to discuss Tom Troland Summary: A very complimentary report Complaint about GO tables being uninterruptible. SDD was tasked to investigate how hard this will be to fix. Note about spectral processor screwups We know about this, and there is nothing planned for now. Lost time over the weekend was due to weather, Front-end (configuration problem), DCR, Spectrometer, and Spectral Processor. We discussed again the fact that we have intentionally decided to pursue development instead of reliability and bug fix work. Spectrometer faults and failures The Spectrometer faulted Monday morning, and was down for several hours. Several lingering problems have combined to make the situation critical. There is a problem with aborting scans that crashess the manager. The spectrometer core dumps without warning. These faults are being addressed this week. [1] Resource calendar schedule conflicts and discussions No conflicts as of now. Tuesday will probably be Maintenance day #1. [2] Observing Schedule discussions Need observing time requests for March ASAP. [3] GBT development planning Results of the allocation meeting See Richard's report at the wiki next week. GB Site goals Phil discussed setting goals for the GB site for CY 2004. These will be articulated to the rest of the site personnel over the next few weeks as they are firmed up. One goal we are discussing is reducing unplanned downtime on the GBT. [4] AOB None. -- JF 8. Any other Business