GBT Operations & Commissioning Meeting 13 August 2004 AGENDA 1. Observing News -- Ron 2. Scheduling Status -- Carl 3. Frontends, IFs, and Spectral Baselines -- Roger 4. Spectrometer Status -- Rich 5. Software Status -- Nicole 6. Project Planning Status -- John 7. Any other Business REPORTS 1. Observing News Since last Thursday, we supported seven observing proposals, in a whopping seventeen observing sessions, and tests of the observing API, Spectrometer Spigot, and the 800 MHz receiver. The SDD spent 10 hours on integration testing and we had four 12-hour maintenance days. We were scheduled for 95 hours for astronomy and 25 hours for the various tests. Lost time this week was moderately low, with a single Spectral Processor problem accounting for more than half the lost time. The average setup time was 45 minutes. The main categories for lost time were: o Spectral Processor : 120 min o Human : 20 min o Security : 20 min o Converter Rack rebooting : 15 min o Telescope Az Transducer : 15 min o All other : 20 min Next week we'll start X-band re-commissioning. Since the spigot will be used, we can expect the setup times to be longer than they were this week. -RJM 2. Scheduling Status Last Week ========= Observations for proposals GBT04B-010, GBT02A-021, GBT04A-003, GBT04B-003, GBT03C-001, GBT04B-004, GBT04A-017, GBT04A-029 Completed proposals GBT04B-010, GBT03C-001, GBT04B-004, GBT04A-017 Next Week ========= Observations scheduled for GBT04A-030 PI Ingrid Stairs High-Precison Timing of Binary Pulsars at the GBT GBT04A-045 PI Mallory Roberts Timing of Three Binary Pulsars Discovered in a Survey of Mid-Latitude EGRET Error Boxes GBT03C-031 PI Bryan Jacoby Timing the pulsars in M62, NGC 6544, and NGC 6624 and Search for Ultra-fast pulsars GBT02A-021 PI Felix Lockman A Search for Recombination Lines from Diffuse Gas in the Galactic Center Region GBT04B-003 PI Alok Singhal The Connection between Galaxy Kinematics and HI Line Widths as Applied to the Distance Scale GBT04B-026 PI Michael Kramer Timing the First Double Pulsar System GBT04B-029 PI Ingrid Stairs Timing New Binary and Millisecond Pulsars from the Parkes Multibeam Survey GBT04B-008 PI Haydon Knight A High Sensitivity Millisecond Pulsar Survey GBT04B-009 PI Joseph Lazio Direct Detection of Baryons in the Local Group: Giant Pulses from Extragalactic Pulsars Scheduled hours [backup] ======================== Category/Month-> August September October November Astronomy ~ 384 331 [154] 150 0 Maintenance ~ 208 210 82 [068] 0 Test & Comm ~ 149 167 [055] 90 0 Un-assigned ~ 3 12 423 0 Proposal Checkouts ================== Awaiting checkout - 39 Active checkout - 5 On Hold - 5 Schedule - 49 Completed - 210 Current backlog [hours prior to 04B*] = 1425 Total time to discharge [hours] = 3165 * Includes projects that are on hold for trimester 04B -- RCB 3. Frontends, IFs, and Spectral Baselines Operational issues: No new operational issues this week. Baselines: We have breadboarded a simple temperature control circuit for the Optical Receiver 4-way splitter. This is now installed in OR1, but only a little time was available for evaluation, and there is nothing to report as yet. Q-band: Work continues on the Q-band receiver. We have borrowed a waveguide filter from CV to help with testing. Ka-band/mmConverter: Reassembly of the inside of the dewar is almost complete, the cold straps had to be remade because the new polarizers moved the amplifiers lower on the waveguide assembly. We plan to start pumping on the dewar on Monday, start cooling later next week and start testing the four DCR channels and all four spectral channels Monday the 23rd. -- GW. X-band: The X-band receiver is ready to go back onto the GBT - scheduled for Monday the 16th. Functional cold tests and thermal cals went well. To reiterate, the work this summer was undertaken to add a polarization crossing switch, and to change the RF and LO filters to provide easier operation outside the receiver nominal frequency band of 8-10.1GHz, specifically to 11.1 GHz. It should be emphasized that we do not claim the receiver works perfectly above 10.1 GHz - the polarizer performance (axial ratio) degrades quite rapidly above 10GHz and the receiver noise shows a 50K spike between 10.5 and 10.6 GHz. However, test observations made last year by one team of observers indicated the receiver performance near 11.1 GHz is satisfactory for their intended observations. The filter changes should streamline observations at 11.1 GHz. R. Norrod 8/12/2004 4. Spectrometer Status Spectrometer Report 6 August - 12 August 2004 *****Operations***** The spectrometer had a few hiccups this week, none of which resulted in much lost time. The first was a failure to respond to a stop command. The second was a failure to respond to an abort command; this one is covered in MR #999. The final one was a Data Interrupt Fault. The spectrometer delivered all but 256 results from the first quadrant, while delivering all results from the other three quadrants. I'm not sure what caused the Data Interrupt Fault. *****Development***** LTA replacement: Finished LTA PCB layout and start to route the power supplies of the board. Cross-Correlation Test Fixture: The design of the filter module is 95% complete. A short design review of this module is planned for 0900 on 8/13/04. Spigot Mode Testing: Progress on mode 25. David fixed his code per the fine print in Ray's documentation and tests of this mode were successful. In addition Karen verified modes 25,26,35,36,65, & 66 using real pulsars. Modes 25 & 26 seem just fine. Modes 35 & 35 consistently produce a tick error (with no error present for any other mode). Modes 65 & 66 were checked against what might be too weak of a pulsar. Spigot Timing: Karen tested modes 2,4,6,16,42,44,46,56 while running simultaneously with BCPM to get the spigot timing offset vs mode. Scott Ransom is analyzing this data. *****Plans***** - Continue LTA replacement and Cross-Correlation Text Fixture development. - Continue spigot mode testing. - Continue spigot timing and mode testing -- Rich, Holly, and Karen 5. Software Status Single Dish Development IPT #93 - Friday, August 13, 2004 This is week 6 of 6 in the fifth development cycle (C5) in 2004. The Plan of Record is available from the wiki at Software.PlanOfRecordC52004. Integration tests for this cycle's releases began on Sunday the 8th, and continued mid-week in preparation for regression testing to begin this weekend. Installation of the new versions of M&Cv4.5 will be on the 19th, and GFM release will occur between the 15th and the 19th TBD. Initial tests went well and only minor issues were encountered. More tests were run with the Observing API. Frank worked with the new observation management database, but some errors from previous sessions were still noted which require resolution. Other reliability issues have been tested and now prove to be resolved. An important new addition since last week has been script validation prior to execution. This week, Joe and Mark folded in the code for the spectrometer to dump from its quadrants in parallel. They were able to increase the dump speeds significantly (to 250 ms) but were limited by NFS speed. The NFS issue will require more investigation. They were able to reliably reproduce the lag dropouts in the spectrometer. Next cycle they will explore adding buffering to the data writing process, which will hopefully allow the spectrometer to dump at a high rate without being impacted by NFS problems. Ray also completed the port of the switching signals selector, which was tested out rather successfully this week during integration tests. Melinda and Ray are working this week to port the receivers, which will be integrated next cycle. Operational Support: + Joe investigated two antenna hardware issues: first, there is something wrong with the switches that indicate wrap position. A software issue was ruled out. Second, Toney reported an azimuth transducer fault which seemed to be related to the first problem, but for which a software fix was not available. -- NMR 6. Project Planning Status August 9, 2004 Planning Meeting Minutes Rm 137 10:45 A.M. [0] Observer comments & operator log items resulting in lost time: Observer's comments: None Operator's log comments Significant failures the past week stemmed from: Computing: None Software: AZ/EL Ephemeris failure, followed by RA/DEC ephemeris failure. IF Manager, Spectral Processor, rogue processes commanding GBT devices The RA/DEC Ephemeris failure (antenna fault at RA = 0) was fixed and patched in. John requested that tests for ephemeris handling be added to the regression tests, since this has been fixed once and the fix evidently lost. The rest of the problems stem from well-known causes. Electronics: LLRADAR backend (observer suppled equipment), Spectral Processor Telescope/Servo: Antenna control software failure Other Problems from Observing Reports: No reports. [1] Resource calendar schedule conflicts and discussions No conflicts noted [2] Observing Schedule discussions Modifed 340 MHz feed -- there is a proposal to modify the GBT's 340 MHz feed to cover another band. More information is needed to know if we can do this or not, given our resources. The S band receiver will need to be pulled off the antenna for 3 weeks after October 1st for maintenance. [3] GBT development planning Next planning meetings -- Meeting is Wednesday morning. Discussion on priorities for next cycle and beyond Our proposed priorities for the next cycle and beyond are to get the Ka band stuff done, put a substantial effort into making the Spigot system easier to handle, and continue on with ease of use and PTCS at reduced levels. No substantial software effort will be allocated to maintenance. Other projects will continue on at existing levels of effort. All this will be discussed ,changed, and ratified at the Wednesday meeting. [4] AOB None. -- JMF 7. Any other Business