Parkes Observatory report
Staff
Rick Twardy has left CSIRO after 17 years' sterling service running the Visitors Centre (VC). In respect of his future Rick says he now knows how Schrodinger's cat must have felt. We all wish him every success for the future, whichever path he chooses!
Another "John" has joined the Parkes staff, bringing the total to four. John Smith started as Manager of the Parkes VC and Coordinator of the Parkes and Narrabri VCs at the end of August. John was most recently in CSIRO Corporate Communications in Canberra, on a 12-month secondment from Livestock Industries in Brisbane.
NASA tracking contract
Contract tracking for NASA began in mid-September with commissioning tests, and has now become a daily occurrence. The new X-band (8.4 GHz) receiver commissioned for this project, teamed with the successful surface upgrade of the telescope (Figure 1; also see June Newsletter) has delivered almost a four-fold increase in sensitivity at this frequency. The receiver is performing much better than minimum specifications, with a zenith Tsys of 25 K. Congratulations go to Graham Moorey, Russell Bolton and the Marsfield receiver team for another world-class piece of hardware.
Figure 1: The final stages of the Parkes dish resurfacing in preparation for the NASA tracking.
The only significant teething problem with the receiver was a tendency for condensation to form on the input dewar window but perseverance, from Brett Dawson and Dave Catlin in particular, has solved this problem and the system is now working perfectly.
John Sarkissian and Stacy Mader have taken on the responsibility of telescope operators for the period of the NASA tracking. Both recently visited Tidbinbilla to study operations there, and several Tidbinbilla staff have likewise visited Parkes. All have found this contact stimulating and rewarding. Lots of accompanying pictures can be found in the status reports at www.parkes.atnf.csiro.au/documentation/mars .
Receivers
In addition to the delivery of the new X-band (8.4 GHz) receiver, two other important changes to our receiver fleet are about to occur.
The 21-cm Multibeam receiver will be removed from the focus cabin in the week of 20th October for refurbishment, and replaced by the new 10/50-cm pulsar receiver. This receiver has run essentially non-stop since its installation in 1997, a testament to the quality of its design and construction. It has however developed signs of aging in the last 18 months, with one completely dead channel (10A), several with high Tsys or unstable gains and, just recently, possible intermittent faults with the all-important central beam. All faulty amplifiers will be replaced during the refurbishment which is expected to take until April 2004.
The new 10/50-cm dual-frequency receiver is designed primarily for pulsar observing but with the increased sensitivity at 50 cm there is considerable interest in observing redshifted HI. One looming problem with the 50-cm band is the rollout of digital TV services throughout NSW, which started in earnest in July this year. Already, three new powerful transmitters have begun broadcasting from Mt Canobolas near the edge of our observing band. Active consideration is being given to shifting the receiver filters to a higher band (690 - 750 MHz approx) to avoid the interference.
Operations
More moderate wind conditions have fortunately continued to prevail since the extremely windy period around January this year. Recent lost-time statistics are:
Observing time lost to faults (year to date) - 1.5%
Observing time lost to wind (year to date) - 3.9%
Observing time lost to wind (since 1 May) - 2.2%
CPSR2, the baseband recorder with a data rate of 1 Gigabit/second, continues to operate well, with operations now simplified to the point where use by non-experts is now straightforward. The wideband correlator is also working well generally, though with a number of niggling bugs still requiring attention.
Computing
Further to the report in the last Newsletter, upgraded cabling has now been installed across the entire site (including the Quarters' bedrooms, for true E-mail addicts) and we have begun moving computers across to it. This process has been delayed by concerns over the cable test results, and the likelihood that substantial retesting will be required. However the cabling is already yielding dividends by allowing high-speed connections to be established between various points of the site very easily, compared to the contortions often required in the past. Once again credit goes to Brett Preisig for keeping this project moving and to Tim Ruckley and Shaun Amy for invaluable support.
Three new Sun Blade 150s have been installed in the control room, replacing older Ultra 1 or 2 machines. A second Sunfire V120 will soon be installed as the main online file server.
An Ultra 10 has been installed in the Quarters conference room, giving guests a Unix option.
Site changes
The main administration building (the Opera house) has been extended to provide an additional office, more library shelving, and a greatly expanded workspace for visitors. It is planned to provide additional workstations (both PCs and Unix) in this area.
Building work at the Quarters continues, with the new ladies' bathroom nearing "first flush". Work will then begin in earnest on the new kitchen.
John Reynolds
Officer-in-Charge, Parkes
(John.Reynolds@csiro.au)>/a>