GBT Operations and Commissioning Meeting 01 October 2004 AGENDA 1. Az track, antenna Report -- 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, antenna Report * The finite element run at ABAQUS finished Wednesday, and data files are being sent to SG&H. Should arrive today. ABAQUS told Joe Antebi the run looked like it successfully completed. * 4 more wear plates will be ordered Friday. * Art continues work on static analyses. -- RAA 2. Observing News This week we supported seven projects in twelve observing sessions. About 16 hours went to PTCS and M&C tests, 8 hours to Ku-band calibration, and four twelve-hour maintenance days, leaving about 100 hours for astronomy. The most significant problem was the loss of twenty hours of pulsar timing data due to our having the wrong frequency standard hooked into the spectrometer. The rest of the week went rather well with 40 min lost due to Az brake problems, 60 min to user inexperience, and 15 minutes to everything else. The average time to setup the system was low as well (35 min). The big news for the upcoming weeks will be the commissioning of the Ka-band receiver. Next week our other support work should be low since there's only a handful of projects scheduled (thanks to Toney's observations!) -- RJM 3. Scheduling Status Last Week ========= Observations for proposals GBT04B-011, GBT03C-031, GBT04B-036, GBT01A-004, GBT04B-029, GBT04C-008, GBT01A-029 Completed proposals GBT04B-036 Next Week ========= Observations scheduled for GBT02B-020 [P] PI Dominic Benford Search for Low Excitation Molecular Gas in High Redshift Quasars (CO) GBT04A-045 PI Mallory Roberts Timing of Three Binary Pulsars Discovered in a Survey of Mid-Latitude EGRET Error Boxes GBT04C-036 [B] PI Rajagopalan Ramachandran Searching for young pulsars in the Cygnus Super Bubble region GBT02B-004 [P] PI Todd Hunter Molecular tracers of high-mass protostellar accretion disks (NH3, CH3C3N, CH3OH) GBT04A-029 PI Scott Ransom S-band Pulsar Observations of Terzan5 and Liller1 GBT01A-004 [P] PI Barry Turner A Search for the Fine Structure of the Hydrogen Atom GBT04C-018 [B] PI Alberto Bolatto A Search for Cosmological HI Absorption Systems Toward Radio Selected Flat-Spectrum Sources Scheduled hours [backup] ======================== Category/Month-> September October November December Astronomy ~ 365 335 [419] 425 [294] 425 [194] Maintenance ~ 210 91 [051] 21 [077] 28 [077] Test & Comm ~ 145 295 [078] 225 [063] 187 [044] Shutdown ~ 0 0 36 36 Un-assigned ~ 0 24 14 69 Proposal Checkouts ================== Awaiting checkout - 0 Active checkout - 11 On Hold - 5 Schedule - 65 Completed - 229 Current backlog [hours prior to 04B*] = 1046 Total time to discharge [hours] = 2641 * Includes projects that are on hold for trimester 04B -- RCB 4. Frontends, IFs, and Spectral Baselines Operational issues: We are investigating the K-band calibration. Initial results may indicate a shift in the Tcal levels in LCP. L-band and C-band receivers will undergo cryo maintenance next week. Baselines: No work this week. Q-band: Gary is acquiring the components and doing the detailed planning to get the extra amplifiers mounted and to move the mixers out of the dewar. He is planning waveguide routing, and mounting of components. Ka Receiver: Receiver and mmConverters installed on Tuesday and Wednesday of this week. Requires M&C version 4.6, scheduled to be released Thursday evening, for significant testing. First observations scheduled for Saturday. Other: First feed patterns were measured on the retrofitted outdoor antenna range. A new azimuth rotator and control computer system were installed and tested. R. Norrod 9/30/2004 5. Spectrometer Status Spectrometer Report 24 September - 30 September 2004 *****Operations***** There was one major problem this week. Spigot timing data was found to be drifting in phase. This was traced to the fact that the spectrometer had been running on a synthesizer since about Sept. 9. My bad... Sorry! *****Development***** LTA replacement: Work on LTA PCB design is continuing. 90% finished. Cross-Correlation Test Fixture: The filter board construction is complete except for installing it into its box. The drawing for the filter box case is in the shop. The schematic for the combiner/output module complete; printed circuit design is continuing. Chassis design has begun. 1.31 msec interference in spigot data: An engineering test of the mode that produces this interference was run on 9/29. No problems were seen. Spigot Mode Tests: Engineering tests were run on all true-200 MHz modes as well as several 800 MHz modes that were never tested. Many passed. Ray will provide a complete write-up soon. Software: Changes were made to the spectrometer code for M&C version 4.6 to allow parallel processing for the data. That is, the control software for the Spectrometer performs three tasks to move data from the hardware to disk. It must read the data from hardware (separately for each quadrant), process the data (mostly de-scrambling the order of the data), and write the data to disk. The changes introduced into release 4.6 allow these sequential steps to overlap as much as possible by using buffering and parallel processes. In fact, there is a thread for reading and processing the data for each of the four quadrants and a thread for each bank for writing the data to disk. Tests were run on Monday to insure that these changes do indeed improve the situation, and everything checked out fine. From an astronomy perspective, the result of this change is that the 'lag drop-out' problem has been eliminated, and the spectrometer can now take data more quickly (have a smaller time value for each phase) than was previously true. However, the spectrometer still must content with the internal network in writing the data which it has taken to disk As a result, it is currently not feasible to take data at the maximum theoretically possible speed, as you may either over-run the memory buffer or simply have too spend too much time per scan in writing the data to disk. A preliminary table showing the 'write-to-disk' times vs. the spectrometer modes is given below. Please note that these times are not absolute, but are extremely dependent upon the network speeds. A more comprehensive look into the network speeds is planned for the next cycle (cycle 7), but the table below should at least give users a reasonable feel for what configurations/integration times are feasible for their project. A detailed look at the results of the tests can be found at http://wiki.gb.nrao.edu/bin/view/Knowledge.SpectrometerPipelining *****Plans***** - Continue LTA replacement and Cross-Correlation Text Fixture development. - Spigot timing tests using new Xilinx personalities. -- Rich, Karen and Holly 6. Software Status Single Dish Development IPT #100 - Friday, October 1, 2004 The sixth development cycle (C6) in 2004 has now ended, and today we start C7 which will run until mid-November. This cycle culminated in a release of M&Cv4.6 on the evening of Thursday, September 30. The Plan of Record is available from the wiki at Software.PlanOfRecordC62004. Release notes showing exactly what changes went into the release can be seen at Software.ReleaseNotes_4_6. Most of this week's activities centered on completing the tests required to ensure a solid build and release. There were several problems encountered in the build process which were ultimately resolved by last night. Special attention was paid to getting the spigot files into the new build, and an SDD rep will be on hand for the first upcoming observation to ensure that all is well. Work on the Observing API and the Turtle GUIs is being wrapped up, in preparation for a training session and release. This should happen within the next week or two. IDL work is surging forward. Bob has made great progress on the common data container for the IDL modules, which will be the basis for the GBT science data model. It is documented at Data.IDLDataContainer and Data.IDLDataContainerTranslation. Anyone interested in data model development should follow the progress of these pages, and feel free to add comments. A strategy for unit testing has also been identified and is being put to use. Operational support included pursuit of the dynamic corrections problems, where pointing corrections were not updating but focus corrections were. More work is required to fully solve the problem, but a patch was put in to alleviate the symptoms when there is a loss of communication. This is also in M&Cv4.6, along with a recovery procedure to follow if dynamic corrections are not updating. Fixes to the transporter are required to finalize the solution, and this is planned for C7. -- NMR 7. Project Planning Status September 27, 2004 Planning Meeting Minutes Rm 137 10:45 A.M. [0] Observer comments & operator log items resulting in lost time: Observer's comments received from: None Operator's log comments Significant failures the past week stemmed from: Computing: Remote observer network trouble (not our end) Software: Spectral Processor hung in stopping, dynamic corrections failed, BCPM manager hang, GFM Richard pointed out that the dynamic correctiosns failure is caused by its connection to grail being disrupted, and that this problem was introduced into the system in the August 15th release. A request to have this new feature removed is in the project office awaiting review. Electronics: RFI/other suspicious IF rack power level fluctuations. Unknown if the data is affected. Galen will have another training session on how to hook up the spectrum analyzer to the converter modules to see the spectrum. Telescope/Servo: Az brake faults. Lots more faults over the weekend. Tim and Bob Goldizen are trying to sort out what caused the problem. It seems that it is not the sensor, as the sensor was moved to another brake last week. Other Problems from Observing Reports: F. Ghigo: 8-phase spectrometer data snafu. BCPM data slowness fixed by the do.lsvortex script T. Minter: baseline problems, Go, IARDS, GFM, config tool Roger will look into the baseline problems. Amy will have the relevant parties contact Toney to get more information on the software failures. [1] Resource calendar schedule conflicts and discussions Ka band installation moved to Wednesday/Thursday. [2] Observing Schedule discussions Latest network outage date The outage is still scheduled for Monday afternoon at 5:00 until midnight. [3] GBT development planning Project presentations Tuesday 10-12 Cycle seven project meeting Wednesday 10-12 [4] AOB Several AOB's were brought up. From Carl Test time requirements for the February to March time frame need to be in as soon as possible, but at least by early November before the TAC meets. From Amy S: 1) the test time allocated for the latest release were insufficent, due to the need to recable the receiver hardware to test the new Linux release. From now on when hardware switches are involved in a release, it may be necessary to coordinate the testing so that it can be done at the end of a maintenance day, in order to save hookup time. 2) More advance notice of changes to hardware would be appreciated. This is in reference to the MM converter changes required last week on the eve of the system being installed. All agree that it would be nice not to have this happen, but the software group was made aware of it immediately upon its discovery. 3) Help is needed to make sure the spigot code is built and installed properly. From Phil: 1) The 140ft MOU is being iterated on. 2) The Penn Array MOU has been amended to allow Simon Dicker to continue to work on the project until it is completed in 2006. 3) There is a movement afoot to have a system in place where observers can request time on several NRAO telescopes with one proposal. This will be released in February. -- JMF 8. Any other Business