GBT Operations and Commissioning Meeting 16 January 2004 AGENDA 1. Az Track and Telescope Status -- Bob 2. Observing News -- Ron 3. Holography update -- Fred S. 4. Frontends, IFs, and Spectral Baselines -- Roger 5. Spectrometer Status -- Rich 6. Software Status -- Nicole 7. Scheduling Status -- Carl 8. Project Planning Status -- John 9. Any other Business PRELIMINARY REPORTS 1. Az Track and Telescope Status Az track * Work continues at SG&H on the FEA's. We have preliminary results from one model (the midspan of a baseplate and wearplate), and further work on it is in progress. The model of the wheel on the wear plate does run now, but shows an unreasonably high stress level at the round edge of the wheel. Calculations are being made to determine what a more reasonable value is. * We have asked for input on the approach of a new track design from SG&H. * An inspection of the track earlier this week revealed no cracks on the top of the wear plates. -- RAA 2. Observing News Because of holidays, vacations, and meetings, we've not had an "Observing Report" for the last four weeks. We should thank Toney, Frank and Glen who put in the long hours while the rest of us were away. Since this is a lot of ground to cover, I'll only give broad outlines of what's been happening. Over the last four weeks, about 575 hours were scheduled for observing, tests, receiver commissioning, and observing setup. About 75 hours of this was lost to the following: Winds - 14 hrs; Weather (Cold, Snow, etc.) - 12 hrs; Hardware Problems/User error - 9 incidents, 18 hrs; Software - 90 incidents, 30 hrs As a ballpark figure, these are about 50% better than what we experienced during the last two weeks in November and the first two weeks in December. But, they are still noticeably worse then the lost time in September/October, probably due in part to the more complex observing performed at the higher frequencies during the cold months. Also, of the 45 hours scheduled for observing setup, about 70% was used for setting up the system and the rest was used for observing. This too is a bit worse than in previous months and may be a result of more complex observing. Probably no one has had the opportunity to see how much observing time has been saved with the new wind restrictions but I would think it has been substantial. Hardware problems, although few in number, usually lasted a couple of hours. They include a few servo problems, the inability to get enough power from the K-band system, a bad K-band beam switch, and missing cables. The K-band beam switch problem we found the other day might be within the dewar (Ouch!). Most of the 90 incidents when we lost time from software problems were about 10 minutes long but about 10 incidents lasted over an hour. In some cases, the observers moved from one software problem to another. A fair fraction of the software problems were from the DCR, Spectral Processor, and Spectrometer. Fewer came from GO, IARDS, and the configuration tool/GRAIL. A few attempts were made at commissioning the Q-band system. Unfortunately, bad weather prevented us from completing commissioning and I've asked Carl to set aside some time next week for finishing this work. I'm still trying to put together the pieces of what was done while I was away and what remains to be done. The system seems to have some stability issues that may have already been addressed. Reports on baseline shapes even with narrow bandwidths, are not as encouraging as we would like. Anyone who has been in the observer's area or cafeteria knows that we've had a large influx of observers in the last couple of weeks. I don't think I've seen so many observers on site since long before the 300-ft collapsed. The observatory is hopping!! -- RJM 3. Holography update 4. Frontends, IFs, and Spectral Baselines (For 1/2/2004 - 1/16/2004) Interface testing between the 26-40 GHz (Ka-Band) receiver and the M&C manager was accomplished and went well. The shop has delivered the receiver mounting frame and the turret cover plate is in the paint shop. Expected RF power has been detected at the dewar outputs in three of the four channels. One Cryo LNA has been returned to the CDL lab for repair. Assembly and interconnection of the major receiver sub-assemblies will proceed for the next 2-3 weeks, and then noise testing will begin. M. Stennes is beginning component testing for the mmConverter project. B. Simon has completed the 7-14GHz microstrip filters. Two higher frequency types will follow on. PF1 is in the lab for replacement of a failed LNA, and repair of one of the IF filter banks. The receiver is scheduled for re-installation on 1/20/04. The S-band receiver was warmed up on Tuesday for refrigerator service. A noisy transfer switch in the IF Router was identified and replaced. -- RDN 1/15/2004 5. Spectrometer Status The spectrometer had problems with 1024-lag-long steps last weekend which resulted in a call-out. The observers were told that this was a known problem and that our long term solution was to redesign the LTAs. A short term solution would be to weed out the scans with the steps. They said they would attempt the latter. The spare spigot card is still non-funtional, even after a trip to Charlottesville. It was established that the xilinx chip on the card can be programmed via an alternate port not available in Green Bank. After being programmed, the chip works normally. It was also established that the chip was having problems going from the programming mode to the operational mode. We will attempt a fimware modification here in Green Bank ASAP. If that doesn't work... Work on the LTA design continues. In the past week timing simulations of the Xilinx designs continued. Karen performed some testing with the spigot system last Wednesday. This will be reported on separately. -- Rich and Holly 6. Software Status Single Dish Development IPT #65 - Friday, January 16, 2004 Today ends week 2 of 6 in the current development cycle. The Plan of Record is now available from the wiki at Software.PlanOfRecordC12004 along with the most up-to-date status information. Significant development has been completed on the enhancements to the active surface required to accept zernike polynomial coefficients as a means of adjusting actuators. Out of six steps, four have been completed. There is still, however, a significant workload left for the remaining four weeks. Considerable progress has been made on the Linux port, where new SIB, MCB, GPIB and MCTime classes have been implemented, establishing a solid foundation for starting work on porting the converter rack and analog filter rack. This will begin sometime next week. For ease of use and data analysis, the new beta data display is being integrated with a generic plotting and flagging tool. Some additional smaller enhancements to the data display are in progress. An informal SDD-only demo is scheduled for late next week. At this point, work will shift to implementation of a generic DCR plugin, completing the gap analysis for spectroscopy capabilities, and supporting collimation for PTCS. Analysis is also underway for reengineering DISH, so that it can be used more interoperably. Operational support this week included constructing a program to rectify some bad scan numbers in device files. GO has since been patched with a fix, but the rectification program is useful for historical data sets that show this error. Also, the blanking parameter value is now being set correctly for a velocity definition of 'topo' in the configuration tool. -- NMR 7. Scheduling Status Last 2 Weeks ============= Observations for proposals GBT01A-061, GBT02A-063, GBT03C-041, GBT03C-012, GBT03A-014, GBT03C-024, GBT03A-015, GBT02A-069, GBT03B-015, GBT03A-016, GBT03B-027, GBT03B-016, GBT03C-006, GBT03A-019, GBT03C-018, GBT03C-007 Completed proposals GBT03C-041, GBT03B-016, GBT03C-007 Next Week ========= Observations scheduled for GBT02C-008 [B] PI Jeremy Darling A Blind HI Survey for Damped Lyman alpha Absorbers GBT02C-030 [P] PI Fred Lo GBT Search for Very Luminous H2O Megamasers GBT03C-024 [B] PI Thomas Troland The magnetic field in high-velocity HI clouds GBT03B-026 PI Mallory Roberts Timing of a Millisecond Pulsar Discovered in a Survey of Mid-Latitude EGRET Error Boxes GBT03B-027 [P] PI Harold Butner K-band Search for Quinoline and Isoquinoline GBT03C-006 [P] PI Edwin Bergin A Search for Ammonia in Proto-planetary Disks GBT03C-018 [B] PI Elizabeth Mayo A critical test of magnetic effects in star formation January ======= Scheduled hours [backup] Astronomy ~ 496 [144] Maintenance ~ 53 [35] Tests & Comm ~ 194 [7] Un-assigned ~ 1 February ======== Scheduled hours [backup] Astronomy ~ 391 [159] Maintenance ~ [141] Tests & Comm ~ 266 [50] Un-assigned ~ 40 March ===== Scheduled hours [backup] Astronomy ~ 161 Maintenance ~ 2 [159] Tests & Comm ~ 24 Un-assigned ~ 557 Proposal Checkouts ================== Awaiting checkout - 18 Active checkout - 23 On Hold - 7 Schedule - 48 Completed - 132 -- RCB 8. Project Planning Status January 12, 2004 Planning Meeting Minutes Rm 137 10:00 A.M. [0] Observer comments & operator log items to discuss Q band glitches We are looking at this. No results yet since maintenance was interrupted by wind on Tuesday. bogus "500 MHz PLL not locked" message This will be investigated. frequency standard discussion We are going to test the rubidium standard to test its suitability as a backup to the maser, and as a primary standard to use during BCPM experiments. Spectrometer core dumps It is not clear why it has started doing this, but it needs to be fixed. K band cable problem A procedure change is in place to hopefully prevent future occurrences. Grail core dumps This is supposed to be fixed and patched into 3.19 Spectram Processor hangs This is thought to be no worse than ever, so it will be monitored. IARDS faults This was traced to bad GO files. No action here. [1] Resource calendar schedule conflicts and discussions Chris Clark needs a day to change Prospero out (2 hrs) No others noted. Chris will schedule his day on one of the floating maintenance days. It will be announced ahead of time that the day will be either X or Y, to be termined by telescope schedules. [2] Observing Schedule discussions Carl noted that Q band observing has not yet been approved for scheduling. We need to do that ASAP to get Q band scheduled this year. [3] GBT development planning 45 ft antenna work This will be cutting in to the tech's available for other work, since we have not hired a tech to handle this station. Tim Weadon and John Ford are working on the servo system upgrade. M&C CME Nicole explained the M&C CME allocation for Cycle 1 was the Linux port of gbteio1 and 2. [4] AOB Carl was proposing that the SDD work on the balancing problems before the calibration problems. Nicole presented a nice roadmap of where they are headed, and we agreed that that was a reasonable approach. I'll let Nicole speak further. Phil mentioned a pulsar spigot computer upgrade that we might consider that is common with the VLBA mark 5 disk based recorder. Rich Lacasse visited the plant while at URSI last week. -- JF 9. Any other Business