GBT Operations & Commissioning Meeting 13 February 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 -- Nicole 6. Scheduling Status -- Carl 7. Project Planning Status -- John 8. Any other Business PRELIMINARY REPORTS 1. Az Track and Telescope Status * Progress continues on the FEA's at SG&H. Two model runs are in progress, and are running faster. May have some results by the end of this week. * Harry reviewed the maximum tilts on splices 17 through 23. He is going to try to adjust shim placement to reduce them somewhat. * A replacement plate for the bridging wear plate 45 was ordered this week so that we can destructively examine the one with the UT indications to determine their nature. * A significant amount of time was spent by Phil, Dennis, Art, and myself on writing a status report on the track this week. -- RAA 2. Observing News Last week's ice storm is the big news. Of the ~150 hrs scheduled for observing or tests, the storm, either directly or indirectly, caused a loss of 56 hrs (48 due to the storm, 9 due to ice/water on the feeds or in the dish). Other lost time was at about 8% of the remaining scheduled time and came from: low temperatures (1 1/2 hrs), server (Prospero) problems (1 hr), Analog Filter Rack MCB problems (3 hrs), and other causes like Spectrometer, M&C, etc (3 hrs). Other noteworthy events: (1) PF receiver checkout and (2) a 19 hr spectral-line integration with 200 MHz that shows remarkably flat baselines (but, unfortunately, no detection!) -- RJM 3. Frontends, IFs, and Spectral Baselines Baselines: Investigation of the Q-band receiver continues. A microphonic LO Multiplier was identified and replaced, which seemed to eliminate the worst of the instabilities in the Beam 2 channels. However, the level of spectral instabilities still seen would limit sensitivity for many experiments. Mid-week we found bias oscillations in two LO Multipliers (luckily two that are not used for beams 1 or 2), which was coupling onto supply and mixer bias leads. This has been cleaned up; testing with the ACS on Friday will evaluate the effect if any of this fix. Other: Work continues on the Ka Receiver and mmConverter. I will provide a more detailed update next week. Operational support has been routine this week. -- RDN 2/12/2004 4. Spectrometer Status *****Operation***** Except for some problems configuring the spectrometer on the first try and DMA errors (nothing new), the spectrometer operated well this week. In addition, both memory boards (reported faulty last week) were fixed (one cold solder joint and one dead IC). The spigot card was also finally fixed! It's not clear what the original problem was (possibly a bad Xilinx chip, a bad trace on the board or lost data in Flash memory), but a second problem plagued us for most of this battle: the loading of the flash from a PC was unreliable. This is something that had been suspected for about three weeks. John Ford helped with some software modifications that made it possible to verify this assertion and additional modifications that made the downloading reliable. *****Development***** Approximately 1.5 days was spent on the LTA card upgrade. In particular, timing simulations for the Xilinx chips continued. Code written for spigot card testing is being cleaned up and archived. A formal test procedure for the spigot cards is being written. *****Plans for next week***** Upgrade the two spigot cards in the system with the new firmware. Bench and system test all the cards. Continue development of the cross-correlation test fixture. In particular complete the design of the noise sources. Continue work on the LTA upgrade. -- Rich and Holly 5. Software Status Single Dish Development IPT #69 - Friday, February 13, 2004 Today ends week 6 of 6 in the current development cycle. The Plan of Record is available from the wiki at Software.PlanOfRecordC12004 along with the most up-to-date status information, and the new Plan of Record will appear at Software.PlanOfRecordC22004 within the next few days. C1 will culminate with the release of M&Cv4.1 on the first maintenance day next week. All PTCS items (not dropped via SDD-sponsor agreement from this cycle) have been completed and tested. GUI enhancements for dynamic temperature corrections, including strip charts, were completed. An MR generated from the prototype generic DCR plugin (for track & tipping scans) is written and is currently pending sponsor approval; work on the plugin itself was actually completed prior to MR approval, so there is a possibility that the code itself is incompleted. This will all be reviewed early next week to determine releasability. For ease of use and data analysis, the new beta data display has been integrated with a generic plotting and flagging tool and has been successfully demoed to some staff astronomers. Exact time of release is TBD but will occur on or about February 16. Coding for the port of the Converter Rack and Analog Filter Rack to Linux is winding down, but extensive changes have been made to so many core M&C libraries that a longer period of dedicated testing should be conducted to ensure that telescope operations will continue smoothly. This activity has been scheduled into C2. A draft of the MR for a security module has also been completed. Ideas for implementation can now be reviewed in upcoming project planning meetings, so that a development approach suitable to everyone is identified. Analysis is also underway for reengineering DISH, so that it can be used more interoperably. The analysis is expected to be written up by 2/27, and involves a smooth transition from old DISH (using glish) to new dish (using python). The new components will be A joint meeting between GB and Arecibo was held late last week to start the process of a gap analysis between our SDFITS (plus needed header additions) format and theirs. In C2 the speed and header issues will be resolved in a way that brings us one step closer to sharing an SDFITS based data format with Arecibo, comprised of a general part and a telescope specific part. SDD operational support this week included: + Several antenna manager and radar glish client fixes to support user defined coordinates, in support of Frank's program checkout. + The configuration tool was patched to allow configuration of the system when using the *MIT backend*. It handles LLRadar and the CGSR backends in version 4.1, but not in 3.19 because of IFManager/cabling file issues. -- NMR 6. Scheduling Status Last Week ========= Observations for proposals GBT02A-063, GBT02A-031, GBT03B-013, GBT01A-058, GBT03B-027, GBT02B-016, GBT02A-028 Next Week ========= Observations scheduled for GBT03C-009 [B] PI Jeremy Darling A Direct Measurement of Fine Structure "Constant" Evolution from OH and HI Absorption Lines GBT01A-061 [B] PI Wendy Lane A blind search for redshifted HI 21cm Absorption GBT01A-054 [B] PI Glen Langston Search for Cyclotron Emission from known Extra-Solar Planets GBT03A-015 [B] PI Wendy Lane A Search for 21cm Absorption in High Redshift Damped Lyman-Alpha Absorbers GBT01A-058 PI Frank Briggs High redshift Damped Lyman Alpha Systems against background Radio Galaxies GBT03A-006 [B] PI Phillip Kronberg Proposal to search for diffuse low frequency synchrotron-radiating extensions of the Coma Cluster GBT02B-016 [P] PI Philip Solomon Dense Molecular Gas and Star Formation in the High Redshift Universe (HCN) February ======== Scheduled hours [backup] Astronomy ~ 360 [173] Maintenance ~ 42 [70] Tests & Comm ~ 293 [27] Un-assigned ~ 2 March ===== Scheduled hours [backup] Astronomy ~ 472 [45] Maintenance ~ 2 [149] Tests & Comm ~ 186 [33] Un-assigned ~ 85 April ===== Scheduled hours [backup] Astronomy ~ 59 Maintenance ~ [149] Tests & Comm ~ 5 Un-assigned ~ 656 Proposal Checkouts ================== Awaiting checkout - 0 Active checkout - 39 On Hold - 7 Schedule - 37 Completed - 145 Current backlog [hours] = 2852 -- RCB 7. Project Planning Status February 9, 2004 Planning Meeting Minutes (revised) Rm 137 10:00 A.M. [0] Observer comments & operator log items to discuss Al Wooten's comments (on the Web) Highlights: Hardware "Everything I used worked well. It would be very very helpful if the 3mm tipper were working." The tipper is being repaired. An encoder for the spinning mirror was found to be bad. A request was made to SDD to change the code so that the tipper completely stops if the encoder is bad, instead of continuing on producing possibly misregistered data. Software "An output data format is sorely needed. The most reasonable solution is SD-FITS, so that the CLASS program or other programs (all of which write data in this format and read it in this format) may be used to reduce the data. 12m data was written in both CLASS format and native format, and a translator to SD-FITS was provided; the GBT should do more than that ancient telescope, not less! " There is ongoing work to support CLASS and SD-FITS already. Documentation "The link to the data reduction on the website leads to a nonexistant web page. Fortunately, I had good notes." The links seem to work, but, alas, point to outdated documentation. 2B16 -- Ron Minor issues with: config_tool Major issues with: phase tables, LO1 error messages, Jim's reduce.g Near show stoppers: I.F. power levels 300 MHz TRCO3_07FEB04 -- Toney 20 MHz filter bad in PF1 Power outage/ Weather discussions The consensus of our group was that the staff did a good job recovering from the ice storm. It was reported that the system was all balled up when the time came to observe for the first time after the power failure. It was decided to remind scientists supporting observations after a power failure that they are responsible for checking out the system and getting it running, and so should come in well ahead of schedule. Indeed, the observers for the next few days should be notified, and they should check their hardware out at the earliest opportunity. Operations was asked to notify support scientists running the next program that a power failure has occured far enough in advance to give them the chance to come in and check out the system. In this case, mechanical and electrical work delayed the startup time, and so the system could not be checked out with the telescope on source, but dummy scans could have been run to find many of the problems that occurred. This should be done in the future. It was also decided that an addition to the weather policy is needed to cover the case such as this where the dish is covered with ice. We will, from here on out, take time away from observing to point the telescope at the Sun to melt off any accumulated ice. this is so that high-frequency observing can resume, and so that the antenna will not sustain dangerous buildups of ice over time. We want to stress again that our group feels that everyone on the GB staff, from Astronomers to Works, did a good job in recovering from the ice storm. This discussion was meant to ferret out any small things that we could do next time to make an even speedier recovery. [1] Resource calendar schedule conflicts and discussions No conflicts, except maybe with things postponed since Friday. Tuesday is likely to be a maintenance day. Bob will move over all items to Tuesday. [2] Observing Schedule discussions Q band problems are perturbing the schedule. We must decide how long to keep it in the lab for repairs and tests. Ka band Carl will provide data on which receiver we will remove to make room for the Ka band. (Later it was decided that the Holography receiver will be taken down) [3] GBT development planning Cycle 2 meetings this week. [4] AOB -- JMF 8. Any other Business