GBT Operations & Commissioning Meeting 24 September 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 We replaced plate 16 this week due to cracks at both ends. 4 nominal thickness plates are on hand, and one 2.125" thick plate. SGH continues work on the models. One has been running since Monday. The same model was being run at ABAQUS as well. It is expected to finish last night or today. Art is working on an analysis looking at the fretting gaps as the possible cause of wear plate cracking. We are contracting with American Stress Technologies to perform residual stress measurements in the wear plates in the coming days. We are targeting the week of December 6 for the Expert Panel Review. -- RAA 2. Observing News It's seems to have been a very light week -- we supported only seven observing projects in nine observing sessions. Maintenance and M&C tests took about 55 and 20 hours, respectively, leaving 93 hours for astronomy. However, lost time was 15% of the time scheduled for astronomy. Almost all of the loss stemmed from high winds (8.6 hrs) and a problem with a new piece of software (statusd, 3.4 hrs). Problems with the BCPM, Spectral Processor, observing setup each caused about 0.5 hrs of lost time. The average time to set up the system was close to the full hour. Next week should be a light load since we'll have about the same number of proposals and observing sessions as this week. The support scientist will meet right after Friday's meeting to hash out what to do about support coverage during the winter holidays. -- RJM 3. Scheduling Status Last Week ========= Observations for proposals GBT04B-021, GBT04B-022, GBT04A-045, GBT02A-044, GBT04C-012, GBT04B-036, GBT04B-026, GBT01A-029 Completed proposals GBT04B-021, GBT04B-022, GBT02A-044 Next Week ========= Observations scheduled for GBT04B-011 PI Barney Rickett Scintillation studies of the J0737-3039 binary system GBT03C-031 PI Bryan Jacoby Timing the pulsars in M62, NGC 6544, and NGC 6624 and Search for Ultra-fast pulsars GBT04B-036 [B] PI Paul Demorest Precision Timing of Binary and Millisecond Pulsars GBT04C-036 [B] PI Rajagopalan Ramachandran Searching for young pulsars in the Cygnus Super Bubble region GBT01A-004 [P] PI Barry Turner A Search for the Fine Structure of the Hydrogen Atom GBT04B-029 [B] PI Ingrid Stairs Timing New Binary and Millisecond Pulsars from the Parkes Multibeam Survey GBT04C-008 [B] PI Yurii Pidopryhora Mapping the Galactic Halo HI: Evidence of Outflow from the Galactic Plane? GBT01A-029 [P] PI Steve Eales A First Investigation of the Origin of Galaxies with the GBT Scheduled hours [backup] ======================== Category/Month-> September October November December Astronomy ~ 364 [019] 335 [420] 425 [294] 425 [194] Maintenance ~ 210 91 [051] 21 [077] 28 [077] Test & Comm ~ 146 [015] 275 [078] 225 [063] 187 [044] Shutdown ~ 0 0 36 36 Un-assigned ~ 0 44 14 69 Proposal Checkouts ================== Awaiting checkout - 0 Active checkout - 12 On Hold - 5 Schedule - 65 Completed - 228 Current backlog [hours prior to 04B*] = 1081 Total time to discharge [hours] = 2720 * Includes projects that are on hold for trimester 04B -- RCB 4. Frontends, IFs, and Spectral Baselines Operational issues: Jim Braatz raised questions about the K-band calibration that will need to be investigated 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 has built a noise/gain spreadsheet model for the new arrangement. Two of four additional amps to be used at room temperature are here, and two more should be shipped today from CV. Some new waveguide sections will be needed. It has been a while since the shop has bent small waveguides, so there may be a bit of a learning curve to climb. Ka Receiver: The video amps "non-linearity" turned out to be an offset, and an artifact of the temporary DCR connections made in the Caltech backend absence. It is thought to be a non-issue, but something that must be accounted for during observations. Testing of the spectral line paths found that insufficient LO power was reaching the mixers. Galen has tested a LO amplifier that provides sufficient power, and is being incorporated. The receiver stability appears good, and we are on track to go onto the GBT next week. The mmConverter MCB interface hardware was completed and tested with PC software; tests with the Linux M&C manager are happening today. Other: A control box has been completed that will make it simple and less error-prone to switch LO references from the Sigma-Tau masers to the rubidium standard. Integration into the system should happen next week. R. Norrod 9/24/2004 5. Spectrometer Status Spectrometer Report 17 September - 23 September 2004 *****Operations***** No significant failures this week. *****Development***** LTA replacement: Work on LTA PCB design is continuing. 80% finished. Cross-Correlation Test Fixture: The filter board construction is complete except for installing it into its box. The drawing for the box for it is being reviewed and should be ready for the shop on Monday. The schematic for the combiner/output module complete; printed circuit design will start momentarily. 1.31 msec interference in spigot data: Ransom found that the interference only shows up in 4-bit modes. He discussed the results of his analysis with Escoffier who will give it some thought next week. The cause of this interference may be in hardware/firmware. It is also possible that the interference is due to incorrect documentation or software de-scrambling. Spigot2 raid: Ransom installed and tested a software based raid controller. This will give the user more direct control over the raids and avoid initialization problems like those experienced by Ransom last week. *****Plans***** - Continue LTA replacement and Cross-Correlation Text Fixture development. - Engineering tests of the remainder of the true-200 MHz spigot modes. -- Rich and Holly 6. Software Status Single Dish Development IPT #99 - Friday, September 23, 2004 This is week 6 of 6 in the sixth development cycle (C6) in 2004, which will culminate in a release of M&Cv4.6 on Thursday, September 30. The Plan of Record is available from the wiki at Software.PlanOfRecordC62004. Integration testing and the first regression testing occurred this week. M&C issues found during integration testing were resolved prior to the regression test. The report from the first regression test is available on the wiki at Software.RegressionTest_4_6_First. Observing API work also continued this week and is winding down. Some testing with the simulated antenna was done. The OnOffSameHA and OffOn scans were tested and seem to operate well. The "wait" statement, which was scheduled for the beta release, is now on hold (no pun intended). Work also continued on getting the graphical Scheduling Block builder operational. We expect to conduct a technical seminar on the usage of the beta Observing API around the time of release (~ first week in October). Most other items on the Cycle 6 POR were also winding down this week. Most effort went to fixing issues found during integration testing and gearing up for Cycle 7 work (e.g. GFM). In support of upcoming Ka Band receiver commissioning, Bob Garwood updated the AIPS++ filler in order to insure so that it will not fail on Ka band data. Operational support was light. -- ALS 7. Project Planning Status September 20, 2004 Planning Meeting 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: None. Software: Spectral Processor hung in stopping, LO1 spurious errors, gbtstatusd crashed antenna system. Spectral Processor and LO1 errors are known bugs, and are on the list of topics to be addressed in the future. The gbtstatusd problem was due to some code that should not have been left running. Electronics: Cryo compressor failure -- X band warmed up. John will ask Roger if it is feasible to have someone in Operations or electronics trained to swap out compressors to avoid the warming in case of failure. Active surface. One IIOP module died, taking 16 actuators out of service. This is a routine failure. Telescope/Servo: Wind , Az brake faults. The culprit brake has been found, but the correction has not yet been made. Other Problems from Observing Reports: Ron reported that the nod procedure may have given bad results with the Ku band receiver. The baselines for that receiver may be affected by satellites in the telescope sidelobes. [1] Resource calendar schedule conflicts and discussions Conflict between M. Stennes and S. White Tuesday. They will work it out amongst themselves. [2] Observing Schedule discussions This week the date for the network outage is a weekday night, October 4th, from 5 P.M. to midnight. [3] GBT development planning Meeting Thursday afternoon to examine the program plan. We will discuss the 140 ft project and science center support. [4] AOB Observing support will be an issue from mid-November through January owing to absences and meetings. Discussions are underway. There will be an IDL design workshop in middle to end of October. We are building 6 additional EoR interferometer nodes NRAO Green Bank has agreed to build room temperature amplifiers for NRL/NRAO projects over the next several months. This will require electronics technicians. -- JMF 8. Any other Business