GBT Operations & Commissioning Meeting 27 August 2004 AGENDA 1. Az track, antenna Report -- Bob 2. Observing News -- Glen 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 Track: * We received the 3 4340 wear plates Thursday. We will try to install one next week as a trial for galling. * SGH has made the 2D run with a patch load. We received some animations just this morning. * No word yet on metallurgical results. Other news: * We have inspected the bad weld in B21R-DB4 and will make a repair in the next couple of weeks. * We are 75 percent complete with converting the azimuth bearings from grease to oil. -- RAA 2. Observing News Observing News, August 20 to August 26 Since last Thursday, we supported six observing proposals, in thirteen observing sessions. We had four 12 hour maintenance days. The VLBI system was checked out by Frank for the Cassini satellite tests to be performed on August 27. We had 102 hours of Astronomy and 6.5 hours of X band Receiver Checkout. Primarily Pulsar survey observations, with an observation of Comets and diffuse gas in the galactic center. Joe Lazio had to use 0.75 hours of observing time for data transfer. Significant loss time due to computer hardware on Vortex, but John Ford and Joe Brandt recovered the system much quicker than we expected. Total computer hardware lost time 7.5 hours, Computer software 3.25 hours, high wind .5 hours, telescope mechanical .5 hours. One hour was marked as lost due to Turtle, but probably should have been listed as testing, not lost time. (Note that there is a grey area between computer hardware and computer software for several of the problem cases). Tony reported some X band spectral baseline ripples that require more hardware checkout. -- Glen 3. Scheduling Status Last Week ========= Observations for proposals GBT02A-021, GBT04B-037, GBT04B-017, GBT04B-008, GBT04B-009 Completed proposals GBT04B-017, GBT04B-008, GBT04B-009 Next Week ========= Observations scheduled for GBT02A-021 PI Felix Lockman A Search for Recombination Lines from Diffuse Gas in the Galactic Center Region GBT02A-046 [P] PI James Braatz Monitoring a Maser Disk in Mrk 1419 GBT02A-003 PI Jeremy Darling Do Hyperluminous IR Galaxies Produce OH Gigamasers? GBT04B-037 PI Scott Ransom A Pilot 350MHz Survey for Fast Pulsars GBT02A-028 [P] PI James Braatz Exploring the Radio Spectrum of Orion A and W51 Scheduled hours [backup] ======================== Category/Month-> August September October November Astronomy ~ 390 331 [150] 324 [083] 404 [082] Maintenance ~ 208 210 91 [051] 21 [077] Test & Comm ~ 146 [006] 174 [059] 270 [016] 158 [012] Shutdown ~ 0 0 0 36 Un-assigned ~ 0 5 60 102 Proposal Checkouts ================== Awaiting checkout - 0 Active checkout - 19 On Hold - 5 Schedule - 71 Completed - 213 Current backlog [hours prior to 04B*] = 1205 Total time to discharge [hours] = 3003 * Includes projects that are on hold for trimester 04B -- RCB 4. Frontends, IFs, and Spectral Baselines Operational issues: No new operational issues this week. Baselines: We continue to make measured progress on the Converter Rack temperature sensitivity. Minor modifications were made to the eight converter modules in Rack A this week and will be evaluated during maintenance periods next week. Q-band: Gary and Roger visited CDL last week to confer with Tony Kerr and Marian P. on the noise power ripple. No obvious cause or solution was identified, but several useful suggestions for tests were made that could help narrow down the search. Ka-band: The dewar is assembled and cooling today (Thursday). Other: The new positioner has been mounted on the outdoor antenna range, and alignment procedures are on-going. The receiver room turret RFI/Air seal was inspected this week. No serious wear was seen on the conductive rubber seal, the original unit that has been in place for several years. During routine quality checks, a fiber IF link (No. 6) with poorer than usual TP stability was noted. The instability was isolated to the optical receiver module and that module was exchanged with a stable unit to keep the link working properly. A modified phase-cal injection scheme for the K-band receiver was evaluated this week. The results were promising, but additional gain needs to be added to achieve the required levels. R. Norrod 8/26/2004 5. Spectrometer Status Spectrometer Report 12 August - 26 August 2004 *****Operations***** Over the past two weeks there has been one significant failure of the spectrometer. Almost three hours was lost after the release of the latest software version. This was the third straight time that a software upgrade resulted in lost spigot time. On each of the three occasions, we all thought there would be no problem. Prior to the next software release, a test spigot observation is planned. Hopefully this will bring any problems to light. A few minor problems with the spigot have also been reported. In mode 56, there has been at least one instance is the pulsar only appearing in half the band. The have also been a few tic errors, but I'm not aware of which modes were being used at the time. Hopefully these are software related. *****Development***** LTA replacement: Had two pumpers in last two weeks. First, one of the key components 1Mx32 SRAM used in new LTA is no longer produced by the manufacture for new customer, the second, one of the important simulation file was ruined with unknown reasons. The good news is that 1MX32 SRAM is replaced by a smaller SRAM, uPDU4416016. All the relevant change are done. The ruined simulation file, finally is fixed, but many hours was wasted. There were a lot of problems happened before when using Xilins simulation program with email box open, such as file couldn't be saved, the program wouldn't do commanded to do, the file was corrupted sometime, and so on. about 20% time used on fixing ruined simulation file or repeat the work had done to reproduce the simulation file. hopefully, the problems can be solved, it will save a lot of time. Cross-Correlation Test Fixture: A short design review of the filter module was held 0900 on 8/13/04. A few good suggestions were gleaned from this, and no major problems were uncovered. The board is just a few vias short of being sent out for manufacture. Spigot Timing: Timing tests using a sine-wave burst have accounted for some of the "missing delay" in the spigot timing. The software drops thirty-two 1.31072 msec frames. This should produce a delay of 41.94394 msec. However, using the BCPM as a standard, a delay of only 39.4 msec is measured. Tests on 8/26 showed that internal spectrometer delays account for 1.25 msec of the missing delay. The spigot delay is slightly mode dependent. Ransom calibrated the delay of modes 42 and 56 this week by observing a pulsar simultaneously with the BCPM and spigot. Spigot true-200 MHz modes: Ray has run into a snag in develop Xilinx personalities for the memory card for these modes. The snag may be serious enough to make the modes impossible. He promised a report by Friday. Spigot Computer: The spigot computer was moved to the "172" network. The hope is that this will help with random failures such as tic errors. *****Plans***** - Continue LTA replacement and Cross-Correlation Text Fixture development. -- Rich and Holly 6. Software Status Single Dish Development IPT #95 - Friday, August 27, 2004 This is week 2 of 6 in the sixth development cycle (C6) in 2004. The Plan of Record is available from the wiki at Software.PlanOfRecordC62004. Much effort has been diverted this week to the preparation of presentations for the upcoming GBT Software Review on Monday, August 30. In particular, work has slowed or stopped on the Beta IDL package, Turtle, and GFM. The release date for the new observing API will slip by three weeks, to 9/17/04. Work on GFM and M&C simulators will not start until then, so these will also slip three weeks. It is hoped that they can be done by 10/19/04, when we return to 2 maintenance days per week. The Beta release date for the IDL code will slip by one month, to 10/30/04, to accommodate a training class plus any early feedback from the panel. Development of Ka Band support, Spectrometer/Spigot fixes, and operational support will not be affected. In support of PTCS activities, Model 4 is now loaded into the database and available for use. In the realm of continuing maintenance and enhancements, a fixed for the LO1 loss of external reference issue has been coded and is being tested. Also some work is being done to address monitoring issues found with sampler2log. All of the receiver managers are in the process of being ported to Linux, including the Ka Band receiver manager. The Ka Band manager code is being updated to ready it for the next batch of commissioning. We have developed a status text file for Spigot Observers, which is the first component of the Spigot Ease of Use effort. -- AS 7. Project Planning Status August 23, 2004 Planning Meeting Minutes Rm 137 10:45 A.M. [0] Observer comments & operator log items resulting in lost time: Observer's comments: Operator's log comments Significant failures the past 2 weeks stemmed from: Computing: Vortex RAID failed, Wind locked up Vortex has been recovered. There was a hardware ailure in the RAID controller. Simply replacing that plus some drives resulted in the system coming up fine. Wolfgang and Chris restored the system to its pre-fault state. No data was lost. The system lockup on Wind is worrisome as a harbinger of things to come, and should be watched carefully. Software: Antenna Characterization, active surface, antenna Manager, spigot software release snafu, GO, IARDS, gbtaio1 (severe ongoing problem of some sort), Spectral Processor hangs, spigot tick errors None of these are particularly worrisome or unknown except the gbtaoi1 errors. That system is scheduled to be retired at the end of September, but it fails too often to keep it going until then. John will talk to SDD about it. Electronics: Telescope/Servo: Wind stow Other Problems from Observing Reports: T. Minter: LO1 step() and monitor() errors, RFI report, spectral processor balance errors The data looked good, so the frequency switching seems to be working right. The step and monitor errors were between scans. The spectral processor balance errors were spurious and unrepeatable. [1] Resource calendar schedule conflicts and discussions Will probably need to clear the deck this morning for Wolfgang to fix the Vortex problems. Spectrometer observing tonight. Amy Shelton, Mark Clark, and Joe Brandt are affected. Suggested they coordinate with Wolfgang. Done. Vortex is repaired. [2] Observing Schedule discussions None [3] GBT development planning Effect of SDD review on development projects. Nicole noted that the release date for the new observing API will slip by three weeks, to 9/17/04. Work on GFM and M&C simulators will not start until then, so these will also slip three weeks. It is hoped that they can be done by 10/19/04, when we return to 2 maintenance days per week. The Beta release date for the IDL code will slip by one month, to 10/30/04. Development of Ka Band support, Spectrometer/Spigot fixes, and operational support will not be affected. [4] AOB Meeting for next week will be canceled due to the SDD Review meeting. -- JMF 8. Any other Business