| Memorandum to: | Ron Ekers |
| From: | Peter Hall |
| Date: | 30 October 1998 |
| Subject: | RFI mitigation |
The ATNF has a number of current programs which are aimed at ensuring greater
electromagnetic compatibility (EMC) between sensitive receivers and other
commercial and custom-built systems. All of our initiatives recognize the
increasing susceptibility of the Parkes telescope to interference and our
efforts are designed to provide mitigation strategies on short, medium and
long timescales. Examples of programs include:
- Design and preliminary construction at Parkes of a transportable
interference monitoring (detection, diagnostic) system for use at
observatories; completion timescale is mid-1999.
- A series of measurements, using newly-acquired test-equipment and a
screened anechoic chamber at CTIP Lindfield, of high-speed ethernet
transmission media and associated electronics, including workstations
and personal computers; recommendations have been passed to groups
responsible for forthcoming installations at Observatories.
- An internal workshop on EMC, with continuing engineering education
focussing on best-practice EMC design and RFI measurement techniques.
Good EMC is challenging and expensive, and it is particularly difficult to
eliminate problems in existing equipment. The difficulty of integrating older
equipment is well-illustrated by the Parkes focus cabin experience; new control
systems designed using contemporary EMC techniques are RFI-quiet, while
re-installation of older electronics caused problems. It is also clear that,
with increasingly fast computers and associated equipment (including
custom-built equipment), there is a very real advantage in moving observing
and staff areas away from the immediate telescope precinct. The ATNF has
begun to consider this approach, together with the allied strategy of one or
more screened rooms at Parkes to house essential data collection and real-time
computing systems. This would involve expenditure of perhaps $200k and
substantial engineering effort.