Parkes Observatory report
STAFF
Two members of staff have left us recently. In June we farewelled Eric Wildner who had worked assiduously with Site Services for 18 months and has now returned to his home town of Winmalee. Eric spent many of his last weeks with us atop a cherry picker working around on and around the tower, surprising the occasional observer with unexpected appearances at the window - just one of his many entertaining contributions to Observatory life over his all-too-short sojourn with us.
Bob Livingstone also of Site Services was farewelled in July. Bob's position as handyman and bus driver at the Observatory began 16 years ago, and it was truly a sad occasion to see the end of an era coming to a close.
The Operations Scientist position (formerly Ian Stewart's position) is currently being advertised and we hope to fill this position shortly.
SITE SERVICES
Site Services spent a large proportion of time over the last quarter continuing the construction and outfitting of the demountable office complex adjacent to the administration building. All new tenants have now moved in to the "Olympic Village", as the complex has been dubbed, greatly alleviating the Observatory's office space shortage.
Re-adhering the delaminating vermiculite on the Tower heat shield has been completed successfully, most of the work being done by Eric Wildner prior to his departure. A final re-coat of the Tower to repair the exposed surface will be carried out once the weather is suitable. Concurrently work was undertaken to repair and upgrade the Observatory water supply system. This should help to mitigate the low water pressure problems experienced during the last four or five summers.
Site services has also played an important role in support of the building project being undertaken to extend and upgrade the Visitors Discovery Centre. This has involved moving 50 tonnes of gravel to provide an all weather access road into the site, the removal of trees and top soil and provision of safety fencing. There has also been a considerable amount of work associated with removal of stores and displays, furniture and projection equipment etc. to allow the building work to proceed. New hand rails, display boards and access paths were all prepared for the re-opening on 12th August.
Planning is also under way for the August shut down when one of the Azimuth jacks is to be removed for refurbishing, some electrical repairs and investigations will be undertaken and installation of new encoders on the Master Equatorial.
OPERATIONS
The 2000 MAYT has seen the nominal completion of the multibeam ZOA (Zone of Avoidance) Survey, while the northern extension of HIPASS and the re-observation of the Sculptor region in Southern HIPASS is progressing smoothly.
The multibeam Galactic pulsar survey is now 78 per cent complete, with a total of 570 new pulsar discoveries. This term has also seen the start of the semi-daily observations of the bright southern millisecond pulsar J0437-4715. This ambitious pulsar timing project is being tackled jointly by the Swinburne Centre for Astrophysics and Supercomputing, and the staff at Parkes Observatory (principally John Sarkissian). The results to date have been excellent, with timing residuals significantly better than for any previous measurements of this kind anywhere. More information on the project is available on the web at: http://mania.physics.swin.edu.au/research/observing /daily_0437
Radio frequency interference (RFI) monitoring and characterisation is continuing at the observatory. John Sarkissian has developed software called "INTER_HPF" that has allowed Mal Smith to process the archived HIPASS raw data files for interference analysis and detection. This work is currently progressing and will hopefully show interference positional dependency on the telescope. A success was registered alomost immediately after this software became available, with the TV camera in the focus cabin identified as a long-standing source of RFI (see below).
Downtime for this term has been very low. Winter months are usually less windy at Parkes and this is reflected in the very low downtime due to wind. Overall, for the period 1 May to 30 August time lost to equipment failures was just 0.8 per cent and time lost to bad weather 0.4 per cent.
RADIO FREQUENCY SYSTEMS
The Parkes conversion system is now essentially complete, with only some minor fine-tuning to be completed. It has performed well in all observations to date, and has made good the promise of greatly simplified observing configuations, particularly for spectral-line observations and VLBI. Thanks to George Graves, Suzy Jackson, Mark Bowen and Mike Kesteven from Marsfield, for their assistance to local staff in commissioning this important new system.
A number of interference sources have been identified in the last few months. One of the main sources of interference, which has been affecting multibeam HIPASS observing since commissioning in Feb 97, is the video camera mounted in the focus cabin. This camera was installed to monitor translator movements in the early days of operational use, and has been the source of interference producing harmonically related tones at 6.75 MHz spacing across the HIPASS spectrum. This source accounts for 8 of the listed 19 frequencies which regularly appear in the HIPASS data. Operationally, observing now occurs with the video camera powered down. The dataset and associated electronics strapped alongside the multibeam receiver package accounts for another 7 of the listed 19 frequencies appearing in the HIPASS data, and work is currently in progress to replace the dataset with a new unit, which has better RFI mitigation techniques. There are 4 remaining intermittent frequencies which appear in the HIPASS data, and a database is currently being assembled, to identify the telescope positional dependency of these interferers. The airport DME interference has reappeared, and efforts are underway to have Air Services Australia investigate the unwanted out-of-band emissions.
VISITORS CENTRE
A major upgrade of the Visitors Discovery Centre commenced in June, with construction of a major addition to the existing building, new toilet block and other facilities. The Centre was closed to the public from 17th July to allow integration of the new work, refurbishment of the existing interior, and a new path from the car park. The centre was reopened on 12th August and has been generating good responses from visitors and staff alike.
The new slide show is complete and was installed on the last weekend of August. Initial reactions from visitors again are very encouraging. A VHS video version of the show is in production, and will be on sale within a month or two. Staff are busy enhancing and enlarging the displays in the Centre, with much work in this area still to be done.
The Olympic Torch Relay came to Parkes on the 18th of August, a day which culminated in memorable scenes of the Mayor of Parkes, Robert Wilson, riding the floodlit dish, the torch held aloft. The event received good media coverage and was an invaluable opportunity to further consolidate good relations with the local community and council.
A film featuring the Parkes Telescope, called "The Dish" is due for national release on 19th October and is currently being promoted in cinemas across the country. A significant increase in visitation to the Vistors Centre is expected to ensue!
COMPUTING
Two new Sun Ultra 10 systems have arrived and will be installed shortly. This will make at least one additional high-end workstation available for visitors in the Opera House.
Multibeam Receiver Monitor - a data logging function has been added to the PC based monitoring program to allow capturing and archiving of data. This will aid in tracking down the source of the cryogenic temperature fluctuations experienced recently, as well as allowing limited remote monitoring.
BECC and FECC - The Back End Control Computer and Front End Control Computers. These projects are in construction, led by Simon Hoyle, to extend the computer control and monitoring of the back-end (Conversion System, Correlator, Cal Control) and the front-end (Receivers) of the observing system. The BECC and FECC will be rack-mounted PCs running the Linux operating system.