Parkes observatory report

Staff

Mal Smith (RF Systems engineer) and Rick Twardy (Visitors Centre Manager) have both taken extended periods of leave. Laurelle Price is now Acting Manager of the Visitors Centre and is doing a truly outstanding job coping with the ever-growing activity there.

The dish cafe

`First coffee' in the new dish cafe was achieved on Wednesday, 9 April. For pictures of the cafe, and of Ron Ekers mastering the art of making a cappuccino, go to www.parkes.atnf.csiro.au/people/jsarkiss/dish_cafe/

Although Ron makes a mean cup you are more likely to find Andrea or one of her staff behind the espresso machine and manning the kitchen. The cafe is open for the same hours as the Visitors Centre (8.30 a.m. - 4.30 p.m., seven days a week) so try it out the next time you are at Parkes.

22 May saw the first evening function at the cafe. Andrew Hunt, Gina Spratt, Rick Twardy and the cafe staff ensured that the event was a great success and the forty visiting Local Government IT Managers had a night to remember.

Visitors Centre record

Easter is always a busy time at the Visitors Centre and with the new cafe up and running this year we were hoping for a good turnout. The result was even better than we had hoped for with an overall increase of 12 percent in sales over the four-day break and a comparable increase in visitor numbers. In the week following Easter the record for the highest sales, excluding the Open Days in November 2001, was exceeded twice!

NASA 8-GHz upgrade

The upgrade of the telescope surface for the NASA tracking of Mars spacecraft in late 2003 - early 2004 has been completed. 180 new perforated aluminium panels have replaced 360 of the original open steel mesh panels extending the perforated surface to a diameter of 54 m. Holography at 12 GHz has revealed that the preliminary adjustment of the surface has already achieved an rms surface accuracy of 0.7 mm over the 54-m diameter, sufficient to achieve the specifications required by the NASA contract and probably slightly better than the 44-m perforated surface prior to the upgrade. A little further tweaking will be performed in the coming weeks. The successful outcome of this project is a tribute to the many who contributed, particularly Barry Parsons and Mike Kesteven from Marsfield, Barry Turner and Tom Lees from Parkes, and the Sydney Engineering team led by Ken Skinner. George Graves, Michael Dahlem, Peter Axtens were all key players in the success of the holography and panel adjustment.

A new high performance 8-GHz receiver being built by the Marsfield receiver group will be delivered to the observatory in July.

Tracking support for NASA starts in earnest in September, rapidly ramping up to around eight hours a day, seven days a week until the end of February, 2004.

The panel upgrade and the new receiver and feed will double the current sensitivity of Parkes at 8.4 GHz. Significant extra performance will also be obtained up to 26 GHz, though the existing feedhorns at the higher frequencies will have to be redesigned to exploit the new surface fully.

Operations news

The breakdown of the El-Nino weather pattern appears to have returned more moderate wind conditions, and a consequent reduction in the fraction of scheduled time lost due to high winds. While 165 hours were lost to high wind in January and February, only 30 hours have been lost in the last two months.

Some niggling questions over the Telescope's drive systems following the major work last September - October on the elevation drive have been resolved, and a number of further improvements made to other areas of the drive system including interlocking and braking systems.

Operational developments

Since the last newsletter, a major project has begun to upgrade the rather ancient voice and data cabling across almost the entire observatory site. After careful measurements by Mal Smith and Brett Preisig showed that unshielded Cat-5 cabling radiated measurable interference, a hybrid network of shielded copper and optical fibre was chosen. This huge task has been managed by Brett Preisig and tackled with unfailing good humour by up to six staff from Allied Technologies, the prime contractors, working 11 - 12 hour days, six days a week. The challenges of installing structured cabling throughout the telescope as far as the focus cabin have both frustrated and excited those involved. All agree it is a far cry from cabling the standard office block. The project has been made possible by CSIRO's corporately funded Cable Upgrade Program with tremendous support from Shaun Wilson of CSIRO's IT Services.

Both the wideband (1 GHz) correlator and CPSR2 baseband recorder continue to be used successfully with a steady stream of minor refinements being made to both.

Two new receiver systems are due for delivery around mid-year: the Mars 8-GHz receiver (see above), and the 10/50-cm concentric receiver, specifically designed for pulsar observing. The new receiver, the wideband correlator and CPSR2 will ensure that Parkes remains at the forefront of pulsar research for some time.

The 21-cm multibeam receiver continues to show signs of age, which is hardly surprising given it has performed in-situ and uninterrupted for more than six years. One channel is completely dead (10A), several others have high Tsys or unstable gains. It is planned to remove this receiver in late September or October for a major refurbishment, and to install the 10/50-cm receiver in its place during this work. The 21-cm multibeam receiver will then be returned, probably early in 2004.

A significant refurbishment of the observatory's online computing systems is underway, with several new Sun and Linux machines either installed or on order to replace some rather old machines such as Sun Ultra 1's.

John Reynolds
Parkes Officer-in-Charge
(John.Reynolds@csiro.au)