GBT OPERATIONS & COMMISSIONING MEETING 07 May 2004 AGENDA 1. Az Track and Telescope Status -- Bob 2. Observing News -- Ron 3. Scheduling Status -- Carl 4. Frontends, IFs, and Spectral Baselines -- Roger 5. Spectrometer Status -- Rich 6. Software Status -- Nicole 7. Project Planning Status -- John 8. Any other Business REPORTS 1. Az Track and Telescope Status Track: * The team reviewed papers found by Art and Joe Antebi on rolling contact stresses in rails. * Plate 45 was re-examined by UT on Thursday. Defects were laid out for destructive examination. * The new plate for 45 was examined and found to be free of defects in the area to be laid over the weld. A non-rejectable lamination was found near one end. * The weld was also re-examined and found to be free of defects. * Other metallurgical work is in progress. * Plate 45 will be replaced next week. Elevation Shaft * Preparation work is under way for repair of the surface defects. Welders are practicing. * A representative from the preheating equipment company also inspected the weldment and made recommendations. -- RAA 2. Observing News This week we serviced only four proposals in 14 observing sessions, a PTCS test, three sessions of proposal checkouts with PF2, and a calibration experiment. About 110 hours went to astronomy and 30 hours (more than typical) went to the various tests. Lost time this week amounted to 11 hrs with almost half in a single incident. This is about 8% of the time scheduled for observing or tests. Typical setup times were 45 minutes. The significant sources of lost time were: Unexplained K-band problem (3B12) : 5 hrs Winds : 2 hrs GFM : 2 hrs Human error : 0.5 hrs CR/AFR Rack software : 0.5 hrs Spectrometer Hardware : 0.5 hrs Other software : 0.25 hrs A 60 min network problem occurred during a time when the winds were up and did not produce directly any significant lost time. We had NO spectrometer software problems. The SDD has installed a 'fix' that promises to reduce AFR/CR problems. Amy has made great strides with GFM. Very nice progress! Item for discussion: The 'test' version of gfm is so much better than the 'released' version we may want to suggest that observers use it instead. PF2 checkouts are almost complete with nothing significant to report. Over the next week Brain & Co. will be performing the engineering tests of the Ka-band system. --RJM 3. Scheduling Status Last Week ========= Observations for proposals GBT04A-050, GBT02A-063, GBT04A-022, GBT01A-064, GBT03B-012, GBT02C-054, GBT02A-046 Completed proposals GBT04A-050, GBT04A-022, GBT03B-012 Next Week ========= Observations scheduled for GBT02A-063 [P] PI Mark Claussen Water Maser Monitoring of Low and Intermediate Mass Young Stellar Objects GBT01A-064 [B] PI James Cordes Search for Pulsars from Point Sources in the Galactic Center GBT03B-011 [P] PI Susanna Widicus A search for sugars in hot cores GBT02C-043 [P] PI Douglas Finkbeiner Microwave Emission from Spinning Dust GBT03C-002 [P] PI Zaven Arzoumanian The Radio Properties of the Shortest-Period Binaries Known GBT03A-016 [B] PI Ingrid Stairs The Physics of a Massive Pulsar System GBT02C-002 [B] PI Christopher Carilli Redshifted HI 21cm Absorption towards Red Gravitational Lenses (J0134-0931, J1004+1229) GBT04A-008 [B] PI Karen O'Neil New HI Galaxy Standards May === Scheduled hours [backup] Astronomy ~ 396 [106] Maintenance ~ 106 [36] Tests & Comm ~ 211 [19] Shutdown ~ 26 Un-assigned ~ 6 June ==== Scheduled hours [backup] Astronomy ~ 311 [11] Maintenance ~ 220 Tests & Comm ~ 167 [15] Un-assigned ~ 27 July ==== Scheduled hours [backup] Astronomy ~ 54 Maintenance ~ 208 Tests & Comm ~ 86 Un-assigned ~ 5 Proposal Checkouts ================== Awaiting checkout - 0 Active checkout - 17 On Hold - 7 Schedule - 63 Completed - 172 Current backlog [hours prior to 04A*] = 1636 Total time to discharge [hours] = 2939 * Includes projects that are on hold for trimester 04A -- RCB 4. Frontends, IFs, and Spectral Baselines Ka-band and mmConverter: The receiver and two mmConverter channels were installed on Wednesday and Thursday. Testing is to begin this afternoon. Production of more mmConverter units continues. Other this week: PF2 was installed as planned, and commissioning process is underway. PF1 filterbank was repaired, and preparations made to do new thermal cals while the receiver is down. Looked into various reported problems. -- RDN 5/6/2004 5. Spectrometer Status *****Operations***** The spectrometer has been working smoothly this week with two exceptions. First there was a problem noted where self-test failed intermittently in quad 2 cards 0 and 1. This was traced (hopefully) to a bad connection between a paddle board and its associated cable (two wires were practically touching). Second, getting data on and off the spigot computer has been a challenge. It is now necessary to record data with one kernel and copy the data off with another. This is clearly not a tolerable situation and efforts are on-going to rememdy it. *****Development***** Progress continued on the Cross-Correlation Test Fixture. One of the two required noise sources was built and tested. It basically works as expected. There is more variation in noise power than was expected, but it should be adequate for the intended purpose. Work was done on both the 200 and 800 MHz filters. Manufacturable designs have been generated and simulated. A little tweaking is still required to take into account the packaging and optimize the bandpass. Component selection for other parts of the filter module has begun. Kaplan and Lacasse conducted additional tests of the spigot 8-bit and 4-bit summed-polarizaion modes. The modes are still not working correctly and it is not clear where the problem lies. Several hooks into the system have been identified and will be used in upcoming tests. They also tested the new spigot computer, spigot2. It worked just like the old one one the first try. The only fly in the ointment is that it did get a tic error in 10 minutes of testing. We have switched back to the old computer, spigot, until this problem can be resolved. Chen continued working on LTA schematic design. *****Plans***** Cross-Correlation Test Fixture: - tweak the 800 and 200 MHz filter designs. - select components for the filter module. - layout the filter multiplexing board. - build and test the second noise source. Spigot: - Additional work is planned on the spigot summed polarization modes and on the "kernel problem". LTA replacement: - Continue schematic design -- Rich and Holly 6. Software Status Single Dish Development IPT #79 - Friday, May 6, 2004 Today ends week 5 of 6 in development cycle C3 in 2004. The Plan of Record is available from the wiki at Software.PlanOfRecordC32004. Release documentation for our latest release and other previous cycles can be found at Software.SoftwareReportCentral on the wiki. Further additions have been developed and are ready for testing within GFM, which is now on its 5th test version of this cycle. Significant improvements in speed, error handling, and ability to handle nonspecific DCR data have been added. These updates will be released at the end of the cycle, once integration and regression testing has been completed. GFM will also be tested with data from the new Ka-band receiver in the upcoming week. Development continued on approved PTCS MRs this week, including new managers for the inclinometers and accelerometers and additional incremental active surface improvements. For the Penn Array Receiver, the MR for a JNI interface to GPIB has been written and approved, and development is underway. A simple test case (turning a power supply on and off) has been identified Operational support over the past week has included: + Another fix patched in on 5/3 for the DCR missed start ticks issue. --NMR 7. Project Planning Status May 3, 2004 Planning Meeting Minutes Rm 137 10:45 A.M. [0] Observer comments & operator log items to discuss Operator's log comments Significant failures this week stemmed from: Computing: Prospero reboots, Naiad display fault, spigot missing ticks Chris Clark informs us that the Prospero problem is a Linux kernel problem, and there is not a ready solution. He is working on some possible solutions. Software: GFM, DCR missed start time, Antenna Manager faults on signal 10 (SIGUSR1), Antenna Characterization, Converter rack Most of these are not new. The antenna Manager faults are, though, and Joe is working on it. Electronics: low power across 4 spectral windows, spectrometer failure in quadrant #2 (This should not have been cured by reboots, etc, BTW), Q band unstable channel (L1) The Spectrometer has a problem with quadrant #2 that needs to be fixd before observing for tonight starts. The Q band receiver needs repairs over the summer, after all. Telescope/Servo: weather, Spurious AZ transducer fault (ongoing problem), Azimuth brake sensor fault Problems from Observing Reports: Karen O'Neil: 4A8 (O'Neil), 1A64 (Cordes) Spectrometer manager dies after too many "aborts" (4A8) Stopping GO table takes forever (4A8) These are both known problems, and the first one (Spectrometer Manager) is being looked at. The second had a fix attempted, which broke other things, and so was removed. No further progress should be expected on this. Frank Ghigo: VLBI BK110 Position switching times did not work out right. Took too long to change sources. Frank will make sure that the VLBI people have the correct numbers for the time it takes to switch between sources, including in the time the fudge factor for the antenna settling time. We discussed fixing the trajectory generator, but it seems that it will be far down the priority list for a while. Glen Langston: Spigot 1A64 (Cordes) Setup difficult, experimental spigot calibration went awry Much discussion on Spigot support. We will need to clarify the status of all the different modes for scheduling purposes. The Spectrometer group will provide input on the available modes that can be scheduled. [1] Resource calendar schedule conflicts and discussions Day #1 OK. Day #2 O.K. [2] Observing Schedule discussions July through September is being scheduled. There are 471 hours in the active checkout queue waiting for a baseline breakthrough. It is felt that the K band ones can be successful if a different calibration algorithm is used, and probably the Ku band ones. Q band will need further study. Carl will move the K band proposals to the schedule queue. [3] GBT development planning Meetings Schedule Cycle 4 planning meeting May 11, 10-12 Project presentation meeting June 15th, 10-12 Cycle 5 planning meeting, June 22nd, 10-12 Wideband spectrometer We will not be able to spend a substantial amount of time on this until 3rd quarter of 2006. Initial engineering test observations in a standalone mode will be possible earlier. [4] AOB Outdoor antenna range turret will be installed tomorrow, since it is not a maintenance day. Dennis will need to borrow some mechanics to help. -- JMF 8. Any other Business