[LINK] The Square Kilometre Array
stephen at melbpc.org.au
stephen at melbpc.org.au
Thu Feb 2 02:20:03 EST 2012
Australias bid for the Square Kilometre Array an insiders perspective
By Lisa Harvey-Smith Square Kilometre Array (SKA) Project Scientist CSIRO
1st February 2012
Australia and New Zealand could be on the brink of a major scientific
In roughly a months time, the site for the Square Kilometre Array (SKA)
radio telescope will be announced.
Australia and New Zealand are competing against a consortium of nine
African countries led by South Africa for the right to host this A$2
billion mega-science project one of the largest and most ambitious
scientific projects ever conceived.
Last year, representatives from Australia-New Zealand prepared a detailed
submission to assist the SKA Site Advisory Committee with its
deliberations. I was lucky enough to be a part of that team.
The document, which exceeded 1,000 pages and included input from more
than 40 organisations and agencies, provided data in sometimes eye-
watering detail on the physical and environmental characteristics of our
candidate site. It also described the social, political and legal
structures relevant to administering the project in Australia and New
Zealand. For several weeks, submissions from both candidate sites were
scrutinised by an international panel of experts.
Very shortly, in the next few weeks, the committee will deliver its
recommendation of the preferred site to the SKA Board of Directors. The
board will then have the final responsibility for choosing a site. This
decision is expected to be announced in mid- to late-March.
The level of anticipation within the scientific community is palpable.
Astronomers, engineers and officials are collectively holding their
breath, awaiting the announcement.
I have witnessed a remarkable level of enthusiasm from the general
public. At an ABC meet a scientist event last year I asked a young
girl of around 11 years old if she knew what a radio telescope was.
Her reply stunned me: Is that like the SKA?, she asked, before
proceeding to tell me there was competition between Australia and South
Africa to host the telescope.
So what makes the ideal site for the worlds most sensitive radio
The primary consideration is, unsurprisingly, the suitability of the
location for radio astronomy. With the rapid expansion of electronic
communications devices such as mobile phones, radio astronomers around
the world have experienced a large negative impact from the encroachment
of stray radio frequency interference into their telescope receiver
This can be extremely damaging to science output and costly to mitigate.
CSIROs existing observatories in rural New South Wales such as the
Parkes Observatory are increasingly suffering from population growth
and the associated radio interference. The problem will be much more
acute for the SKA, which will be more sensitive and observe over a very
large frequency range, in order to pick up signals from the distant
To avoid such man-made interference, CSIRO, working with WA State and
Federal Governments, has established the Murchison Radio-Astronomy
Observatory in one of the most remote areas of Western Australia.
By way of contrast, the region within 100km of CSIROs Paul Wild
Observatory near Narrabri, NSW, has a population density of one person
per square kilometre. Within 100km of our candidate SKA site, the figure
is 100 times lower.
In order to protect this extraordinarily radio-quiet region, CSIRO and
government agencies have negotiated a strong legal framework to protect
the Murchison Radio-Astronomy Observatory for generations to come.
The SKA will comprise a number of different receiver systems, which will
enable observations over a large frequency range. There are strong
scientific advantages of placing these systems at a single, high-quality
the infrastructure cost is shared between the high- and low-frequency
receivers, increasing the available budget for the (scientifically
productive) hardware and active components of the telescope
the scientific return of a geographically distributed telescope is
diminished because simultaneous observations of the sky over a large
frequency range would be impossible
if man-made interference were greater at one location, it would
inevitably diminish the science return to place any antennas on the site
more afflicted by radio interference.
For these reasons, I have no doubt that the merit-based process to
identify a single site for the telescope is the correct approach. Given
the SKA will inhabit one of the last remaining radio-quiet sites on
Earth, the quality of science is not an area in which we can afford to
I have heard the SKA site bid compared to an Olympic bid, but in many
ways that understates the significance of the project. A successful SKA
telescope will provide a massive boost for science worldwide, together
with the spin-off benefits that flow from such internationally focused
innovative technology projects.
This will happen, provided the very best site is chosen to enable maximum
potential for scientific discovery and maximum engagement from the global
Australia and New Zealand have incredibly strong credentials to support
the SKA on behalf of the whole world for the 50-year lifetime of the
instrument. I hope in 2012 an Olympic year we ensure scientific
excellence emerges from this process victorious.
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