GBT Commissioning & Operations Meeting 13 June 2003 AGENDA 1. Az Track Status -- Bob A. 2. Spectrometer status -- Rich 3. Commissioning and Observing Checkout News -- Ron 4. Spectral Baseline, Front-end, and IF work -- Roger 5. Software status -- Nicole 6. Project scheduling -- John 7. Observing schedule -- Carl 8. Any other business PRELIMINARY REPORTS 1. Az Track Status * All trial modification work was completed Wednesday.  A lot of work by over 30 NRAO people made this happen.  The work was finished without injury and ahead of schedule. * A tilt data run shows that a peak to peak of 0.19 degrees  is still present.  We expected it to be nearly 0.  We may lift the wear plate back off to see how the shim material settled. * We received a preliminary report from Simpson, Gumpertz, and Heger on the 2-dimensional finite element model.  This work is progressing. We've asked for some modifications and additional plots to evaluate it's validity. -- RA 2. Spectrometer status Rich is on vacation! 3. Commissioning and Observing Checkout News Ron reports no significant news (it has been mainly drift scan work since last week). 4. Spectral Baseline, Front-end, and IF work The X-band receiver was warmed to replace a temperature sensor, and the vacuum window was also rebuilt due to a failure that evidently happened since the receiver was removed from the GBT. All the waveguide joints in the feedhorn and circular waveguide were inspected, buffed to remove chromate conversion coating, and repaired as necessary. Several metal chips deep in the feed corrugations were found and removed. The receiver was cooled again on Wednesday night. Testing with the spectrometer on Thursday did not show whether the work on the feedhorn changed the performance - probably testing on the antenna will be needed to know. Testing will continue Friday, and the receiver will be installed on Monday. Isolation measurements on an Optical Receiver module showed that isolation between outputs is about 19dB worst case. Measurements in Converter Rack A showed a crosstalk mechanism between channels which share a LO2 synthesizer (CM1 & 5, 2 & 4, etc.). The level of crosstalk depends on mixer R-L and L-I isolation, and isolation in a circulator and power splitter. Near 1 GHz the crosstalk is about -45dB; at 3 and 6 GHz about -72dB. Negotiations for a statement-of-work were completed with the manufacturer of the compensated optical modulators (re: 2.4MHz ripple). The order for new units should go out next week. Quoted delivery is 6-8 weeks ARO. -- RN   5. Software status Software Development Division #39 - Friday, June 12, 2003 The release of M&C v.3.14 planned for 6/4/03, and delayed because of the telescope shutdown, was released on target Thursday, 6/12/03. The plan of record which shows goals for M&C v3.14 is available at http://tryllium.gb.nrao.edu/images/POR_May03.pdf. Key accomplishments this month will be described on the release notes, which will be made available shortly and will be posted at http://projectoffice.gb.nrao.edu. Tests are planned to characterize the antenna trajectory preprocessor fix through early next week; results will be described in a comprehensive memo. Work has started on the new Plan of Record for the month of June 2003 and is available at http://tryllium.gb.nrao.edu/docs/POR/POR_June03.pdf. M&Cv3.15 will be released on or about July 2, 2003, along with the Metrology system and a fully tested new component for EMS. Phase 1 of the Antenna Test Range software, built on the foundation that was coded last summer during Phase 0 of the project, is scheduled for completion in the next (August) release. Please visit our updated web site at http://projectoffice.gb.nrao.edu, where we are now actively integrating telescope control and data analysis activities. Also, our status board describing the latest news about items on our current Plan of Record is now outside Nicole's office. If you have any questions about the status of your development, feel free to refer to "The Board". A significant amount of operational support was provided this week in software and electronics troubleshooting for the BCPM. -- NMR 6. Project scheduling 0) Observer comments None (Drift scans seem to be going well for the most part) Ron told us that his spectrometer observations were working well, with fewer failures per session than we've been seeing. Glen has reported almost daily on the pulsar drift scans. they are going well, too. 1) This week's schedule Track work Should finish on time Thursday afternoon. Contractor is finished with his work. Alma tests Continuing this week due to a problem last week that cost a couple of days. The tests are going well otherwise. Spectrometer Spigot card tests This week's tests were cancelled due to the ALMA tests and Rich Lacasse vacation time. PTCS will use one daytime maintenance period this week to do tipping rangefinder tests. 2) Next week's schedule Nothing noteworthy. 3) June Observing Schedule discussions Discussed possible uses for this weekend's observing, which seems like will be supported by a fully mobile GBT. 4) July Observing Schedule discussions Discussed the need to remove the PF1 for more than the 2 weeks allocated. 5) 6 month plan review Discussion on plan to date. I'll be finishing this the week of June 9th. Discussed the review of the 6 month plan. Decided that we will align these plans with the calendar quarters, and decouple the reviews from the calendar as needed. The new version of the 6 month plan will cover fron July 1 to the end of the year. 6) AOB HVAC RFI (340+ MHz) The 340 MHz band is badly contaminated with RFI. 2 sources have been found: the LO reference receiver adn synchronizer, and the GBT HVAC air handlers. The LO Reference Receiver circuits are being redesigned to be able to shield and filter them. We discussed the relative priority of the HVAC system RFI in relation to anechoic chamber testing of other proposed devices, and concluded that suppressing the known RFI was more urgent than testing additional proposed devices, and that they would have to wait for time in the chamber. IPG Progress report Jeff Acree supplied John with a progress report on the IPG efforts this year. There has been notable progress repairing the shielded control rooms, improving the shielding on the GBT servo system, and in supressing RFI from a number of other sources. THere is considerable activity in the NRQZ front, as well. Things that are in danger of falling off the active list are improving the monitoring system, doing regular RFI searches, and doing a calibration of the propagation model used for NRQZ license application studies. -- JF 7. Observing schedule Last week ======= Observing: GBT03B-007, GBT03B-009, GBT03B-034 June === Shutdown ~ 11 hours Astronomy ~ 386 hours Maintenance ~ 184 hours Tests & commissioning ~ 139 hours July === Astronomy ~ 324 hours Maintenance ~ 218 hours Tests & commissioning ~ 203 hours August ===== Astronomy ~ 329 hours Maintenance ~ 192 hours Tests & commissioning ~ 162 hours Ua assigned ~ 60 hours -- RCB 8. Any other business The BCPM failed to come back to normal operation after the power outage last week. Amy, Bill and John have been working on it with considerable assistance from Don Backer remotely. It will be out of operation until Wednesday 18th at the earliest. The metrology group have been using the track shutdown period to check the alignment of a number of rangefinders, in preparation for Kim to do a survey of the tip of the feed arm as it is moved in elevation. This will provide a data-set for use with the Engineering Measurement System R. Prestage 6/13/03