GBT Operations & Commissioning Meeting 2 July 2004 AGENDA 1. Az Track and Telescope Status -- Bob 2. Observing News -- Ron 3. Frontends, IFs, and Spectral Baselines -- Roger 4. Spectrometer Status -- Rich 5. Software Status -- Amy 6. Project Planning Status -- Bob/Phil 7. Any other Business PRELIMINARY REPORTS 1. Az Track and Telescope Status No developments (as of this writing) on the azimuth track. Art completed a model of the elevation walkway with the proposed additional clip. The adding of the clip would have imposed an additional moment onto the structural member R6; therefore, the clip was not added. The lower clip was repaired by grinding and welding Wednesday. This work is now complete, and will be monitored periodically for changes. Structural inspectors will not be working next week. A significant amount of time is being flexibly allocated to PTCS thermography before they have to send the camera back. Access to the tipping structure is only planned for Tuesday morning; more may be available later in the week. -- RAA 2. Observing News We had a rather light week since we supported only five observing projects, one of which was a VLBI experiment, in nine observing sessions. There was 30 hours scheduled for tests (PTCS, Software, GASP) and 90 hours for observing. Average setup time was low (35 minutes) and, if I ignore the software tests, lost time was well under 1 hour! The only items of interest were: C-band warming up; a blown fuse on the Active Surface that might have reduced the telescope's efficiency. The last I heard, the GASP tests were going OK. On Thursday we rescheduled the observing support for August because of recent changes in travel plans and to prepare for Toney's stint on jury duty. We can expect we'll have a bit more support work next week since the number of projects is higher, their complexity is greater, and we'll have a weekend holidays when many will be away. -- RJM 3. Frontends, IFs, and Spectral Baselines Operational issues: The frequency of "5MHz/1PPS Sync" faults has again increased. We believe they are not affecting data quality, but Mike Stennes is attempting to isolate the cause. Baselines: Waiting on a demo 4-way power splitter unit that was to be shipped on 6/29/04. Q-band: Continue to test components. We expect to cool the receiver again next week. Ka-band/mmConverter: Wiring of the five mmConverter modules continues. Two units are completly wired; two more are at 50%. The power supply/LO chassis is being assembled. The receiver LNAs have been temporarily sent to CV for bias optimization. Linearity: Work is on-going to improve the manufacturing characteristics of the 0.5-8GHz amps that will be used in the Optical Driver Modules. New artwork is nearing completion. Rework of one of the non-linear ODMs was completed and placed back into service (to ODM 3). A amplifier was replaced, levels were adjusted, and zero offsets were adjusted. Afterwards the square-law detector output is linear to better than 1% for voltages between 0.1 and 5V, and degrades to 2% at 10V. The microwave gain (affecting the spectrometers) is linear to better than 1% to 10V on the detector - the 1% gain compression point is about 3dB higher power than that which produces 10v on the detector. The repeatability of the lab linearity measurements is about 0.5% p-p. R. Norrod 7/1/2004 4. Spectrometer Status Spectrometer Report 25 Jun - 1 Jul 2004 *****Operations***** It was a quiet week except for a few bad lags in the data. *****Development***** The uploading of scaling of offset coefficients to the spigot cards from the spigot computer has not been 100% reliable. In an effort to improve this, firmware and software were written to perform a CRC on the coefficients. The CRC of the data received by the spigot can be compared to that sent by the spigot computer. A second iteration of software has been written; it needs to be tested. A large amount of effort went into the testing of spigot timing. Small, very repeatable differences in the delays of various modes have been found. A report on the tests is in progress. Some effort has been put into studying the lag step problem. Old data has been analyzed and tests are underway to reproduce the problem. Some effort is also going into the LTA replacement. A small amount of effort went into the Cross-Correlation Test Fixture. In particular, layour of the 12.5 and 50 MHz filters was nearly completed. *****Plans***** Spigot: - Test spigot card firmware modifications. - Meet with pulsar scientists to decide what to do next with respect to testing spigot timing. - Continue work on absolute timing of spigot data vs mode. Lag drop-outs: - Continue work on finding the cause of 1024-lag-long pulses in acfs. -- Rich, Holly and Karen 5. Software Status Single Dish Development IPT #87 - Friday, July 2, 2004 Today begins Week 1 of 6 in the fifth development cycle (C5) in 2004. The Plan of Record which shows what you can expect in these releases is available from the wiki at Software.PlanOfRecordC52004. Documentation showing results from our integration and regression testing, and other previous cycles release information, can be found at Software.SoftwareReportCentral on the wiki. The releases of M&Cv4.4 and GFM4.4 occurred on Wednesday, June 30th. Release notes for M&Cv4.4 can be found on the wiki at Software.ReleaseNotes_4_4. Release notes for GFMv4.4 can be found on the wiki at Data.GbtFitsMonitorReleaseNotes4_4. M&Cv4.4 features a major revision/refactoring of Grail. The main change is that the new Grail only registers Manager parameters on demand. Also, Grail writes only errors to its log files, keeping log file sizes more reasonable. The full notes are available on the wiki at Main.GrailNotes (section '06/30/2004'). Observing API tests continued for a few hours each day this past week. An Execution Block GUI is being used to interactively run the tests. We expect to release the beta version of the Observing API on Friday, July 9. Details on the Observing API, including its usage, can be found on the wiki at Data.ObservingAPIBeta. Amy Shelton will be giving an overview of the documentation and the Observing API as well as answering any questions that anyone might have at the commissioning meeting. Work on the Linux Migration project has resumed this cycle as a background task. As a first step we are doing an inventory of all managers that still have at least one VxWorks component. Details can be found on the wiki at Software.LinuxMigrationDetails. Work on the GBT IDL data reduction package also continues this cycle. The project page can be found on the wiki at Data.IDLMain. Operational support was light over the past week; nothing particularly note-worthy. -- Amy 6. Project Planning Status (Abbreviated minutes from Bob in John's absence.) 1. Observing problems: We scheduled in a check on C-receiver's refridgerator for Monday evening, with a second to turn off the vacuum pump Tuesday morning. Ron correctly pointed out that Ingrid/Don Backer's work doesn't fit the criteria we have for critical activities during observing sessions. Phil will ask Karen O'neill to act as a point of contact with them, and I will ask Rich to designate an engineering chaperone to make sure they don't jeopardize our other equipment, without assuming their work. Phil was also going to talk with Ingrid about avoiding working risks during observing. 2. Resource Calendar: All day Wednesday is needed at access to accomplish the repair of the elevation walkway. The structural inspection team will not inspect next week. We are trying to accomodate PTCS's needs for IR work. 3. Other Business: we coordinated vacation plans for this summer. We also scheduled next week's meeting on Tuesday. 7. Any other Business