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The Square
Kilometre Array –
Australia Misses Out
By GEOFF GRAHAM
One of the first ASKAP dishes
to be constructed at the
Murchison Radio-Astronomy
Observatory in Western
Australia. Photo credit: Paul
Bourke and Jonathan Knispel.
Supported by WASP (UWA),
iVEC, ICRAR and CSIRO.
Most readers will have heard of the Square Kilometre Array
(SKA) radio telescope project which SILICON CHIP reported on in
the December 2011 issue. It was supposed to be a bidding contest
between Australia and South Africa. In simple terms, South
Africa won and we lost. But that’s not the end of the story.
16 Silicon Chip
siliconchip.com.au
An artist’s impression of the high-frequency dishes that will be installed in the Karoo desert in South Africa. These are the
type of antenna that we normally associate with a radio telescope. Photo credit: SKA Organisation/Swinburne Astronomy.
T
HE SKA IS A $2.5 billion international project to build a giant
radio telescope using thousands of individual dishes spread over thousands
of kilometres. Using immensely powerful computers, yet to be developed,
scientists hope to combine the signals
from all these dishes to give ultra-clear
and sensitive images of the radio sky.
With such a big project on offer, the
competition for the right to host the
SKA was fierce and it came down to
a contest between South Africa and
Australia/New Zealand. Australia’s
proposed site was in the Murchison
region of Western Australia and we
even went as far as building the $220
million ASKAP radio telescope on
the site, partially to demonstrate our
capability in this field.
As was widely reported on 25th May
2012, the SKA Organisation decided
to share the telescope between the two
contenders. This seemed like a simple
enough decision and a win-win for
both sides. But is it?
Making the decision
To evaluate the competing bids,
the SKA Organisation (headquartered
in the UK) formed a Site Advisory
Committee and they concluded that
either site was suitable. In the end,
their recommendation was to host the
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project in South Africa. This advice
was based mostly on technical factors,
which included a more favourable
layout of the array in southern Africa
and lower operating costs (political,
socio-economic and financial factors
represented just 2% of the decision).
By many reports, this recommendation led to a fierce debate within the
SKA community, with non-technical
issues being raised. According to reports, the debate became acrimonious,
with allegations of dirty tricks and
political high-handedness. The public
was unaware of this battle but a sure
indication was the premature leak of
the committee’s recommendation to
The Sydney Morning Herald in March.
The final decision on the telescope’s
location was the responsibility of the
international members of the SKA
Organisation who did not bid (Canada,
China, Italy, the Netherlands and the
United Kingdom). Their debate was
held behind closed doors but it has
been reported that the three European
countries favoured South Africa, perhaps because it was closer to Europe
and they would have better control
over the project. Reports also claim
that Canada and China favoured the
Australia/NZ bid because of the better infrastructure in Australia and the
political instability of some countries
in the South African consortium.
Faced with this stand-off, the de
cision was a typical bureaucrat’s solution; split the project between the
competing countries.
Practical results
The next issue for the SKA Organisation was how to divide up the project.
Because Africa and Australia are on
different parts of the globe they see
different parts of the sky at any one
time. This means that the SKA could
not simply share the telescope’s dishes
between the countries, as they all had
to be looking at the same part of the
sky at the same time.
So the decision was made to deploy the main telescope with all the
high-frequency dishes to South Africa
while Australia would have the lowfrequency aperture array scheduled
for deployment later as part of Phase
2. In practical terms, this means that
the majority of the telescope will be
built in Africa. The official statement
describes it as a split of two thirds to
Africa and one third to Australia/NZ
but given that full construction of the
less important low-frequency aperture
arrays will only commence in Phase 2
(around 2020), most of the observable
activity will be in Africa.
In Australia, this was reported as
July 2012 17
The Dense Aperture Array will be used to survey the mid-frequencies and will also be installed at the SKA site in the
Karoo desert in South Africa. Photo credit: SKA Organisation/Swinburne Astronomy.
a “win-win” situation but in South
Africa it was heralded as a triumph
for Africa while deploring the associated compromise forced on to them by
political expediency.
For New Zealand, the result is quite
disappointing. The low-frequency aperture array will be in the Murchison
region of Western Australia and it is
This map shows the proposed layout
of the high-frequency dish array
throughout Africa. Credit: SKA South
Africa.
18 Silicon Chip
difficult to see how this could be extended to New Zealand.
Three types of detectors
The SKA was envisaged from the
start as consisting of three types of
detectors:
(1) The high-frequency dishes, ie, the
traditional steerable dish types that
most people associate with a radio
telescope;
(2) A medium-frequency array covering roughly 0.5GHz to 3GHz. This
will be primarily a survey instrument,
exploring the evolution of galaxies,
dark energy, transient sources and the
realm of strong gravity; and
(3) A low-frequency aperture array
covering about 70-300MHz which will
be used to investigate the epoch of reionisation and some transient sources.
The high-frequency dishes and
the medium-frequency array will be
installed in Africa while the lowfrequency aperture array will be
installed in Australia. Both the medium and low-frequency arrays are
new technology and both countries
will experiment with them in Phase
1 but full construction will only start
in Phase 2.
The low-frequency aperture array
to be installed in WA will probably
consist of arrays of “droopy dipoles”,
one for each polarisation and arranged
into stations in a fixed pattern on the
ground. The signals from each dipole
will be combined using computers to
observe a number of large areas of the
sky simultaneously. This is different
from the traditional telescope where
a dish is aimed at the source and the
signal is bounced from its surface to
the focus where it is captured.
The future of the SKA
The decision on where to locate the
SKA is not by any means the end of
the story. One of the big issues facing
the SKA will be to obtain sufficient
funding to begin construction. To date,
only a small amount of seed funding
has been provided by the SKA member
countries and this has been used for
items such as the construction of the
SKA’s headquarters and staff salaries.
Soon, serious funding of hundreds
of millions of dollars will be required
and it is difficult to see how hardpressed countries like Italy and the
UK can find this sort of money when
their citizens are forced to suffer under
government-imposed “fiscal austerity”. Non-European countries like the
USA are not in a much better position
and given the world’s present financial
crisis, $2.5 billion is a lot of money
to spend on something that could be
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Above: artist’s impressions of the low-frequency array that’s destined for the Murchison in WA. Phase 1 of the SKA
project will involve experimenting with them while construction will start in Phase 2 (2020 or later). Photo credit: SKA
Organisation/Swinburne Astronomy.
Above: an elevated view of four of CSIRO’s new ASKAP antennas at the Murchison Radio-Astronomy Observatory in
Western Australia, October 2010. Photo credit: Ant Schinckel, CSIRO.
deferred until times are better.
Consequently, it is very likely that
the various target dates for the project
will slip and that could push out the
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date for the construction of the lowfrequency aperture array in Australia
even further than 2020. In fact, it might
never happen at all.
Another issue that the SKA has to
face is the effects of creeping bureaucracy and national rivalries, some of
which has already become apparent in
July 2012 19
The Full Statement From The SKA Organisation
The Members of the SKA Organisation today agreed on a dual site
solution for the Square Kilometre Array telescope, a crucial step towards
building the world’s largest and most
sensitive radio telescope.
The ASKAP and MeerKAT precursor dishes will be incorporated into
Phase I of the SKA which will deliver
more science and will maximise on
investments already made by both
Australia and South Africa.
The majority of the members were
in favour of a dual-site implementation model for SKA. The members
noted the report from the SKA Site
Advisory Committee that both sites
were well suited to hosting the SKA
and that the report provided justification for the relative advantages and
disadvantages of both locations, but
that they identified Southern Africa
as the preferred site. The members
also received advice from the working group set up to look at dual site
options.
The majority of SKA dishes in
Phase 1 will be built in South Africa
combined with MeerKAT. Further
SKA dishes will be added to the
ASKAP array in Australia. All the
dishes and the mid frequency aperture arrays for Phase II of the SKA will
the site-selection process. While some
major science projects like the Large
Hadron Collider at CERN have avoided
this problem, the international fusion
reactor project (ITER) under construction in the south of France illustrates
just what can go wrong with a giant
project funded by many competitive
countries.
This latter project has had numerous
cost overruns and delays, partially due
to the bureaucratic squabbles between
the seven major countries involved.
There are plenty of examples where
a section of the project designed and
built by one country will not integrate
with another section produced by a
different country. The has resulted in
arguments, accusations and a project
that has been delayed time and time
again.
Australia’s SKA Pathfinder
The Australian SKA Pathfinder
20 Silicon Chip
be built in Southern Africa while the
low frequency aperture array antennas for Phase I and II will be built in
Australia/New Zealand.
“This hugely important step for
the project allows us to progress the
design and prepare for the construction phase of the telescope. The
SKA will transform our view of the
Universe; with it we will see back to
the moments after the Big Bang and
discover previously unexplored parts
of the cosmos” says Dr Michiel van
Haarlem, Interim Director General of
the SKA Organisation.
The SKA will enable astronomers
to glimpse the formation and evolution of the very first stars and galaxies
after the Big Bang, investigate the
nature of gravity, and possibly even
discover life beyond Earth.
“Today we are a stage closer to
achieving our goal of building the
SKA. This position was reached after
very careful consideration of information gathered from extensive investigations at both candidate sites,”
said Professor John Womersley, Chair
of the SKA Board of Directors. “I
would like to thank all those involved
in the site selection process for the
tremendous work they have put in to
enable us to reach this point”.
(ASKAP) project is currently under
construction by the CSIRO in the Murchison region of Western Australia, at
the same site proposed for the SKA.
Australia has invested a lot of money
(over $200M) on this project and it is
tempting to ask what effect the recent
SKA announcement will have. After
all, it was touted as a demonstration of
Australia’s capabilities in the competition to attract the SKA to Australia.
In fact, with ASKAP, Australia has
done a great deal more than South Africa in committing funds and building
something concrete.
The ASKAP is a great radio tele
scope in its own right and it will be
many years before the SKA, ultimately
to be built in Africa, will be in a position to eclipse it. Even then there is a
lot of sky to look at and many scientists
will queue up to use the ASKAP for
projects that cannot be done using
the SKA.
Factors taken into account during
the site selection process included
levels of radio frequency interference,
the long term sustainability of a radio
quiet zone, the physical characteristics of the site, long distance data
network connectivity, the operating
and infrastructure costs as well as the
political and working environment.
The agreement was reached by
the Members of the SKA Organisation who did not bid to host the SKA
(Canada, China, Italy, the Netherlands and the United Kingdom). The
Office of the SKA Organisation will
now lead a detailed definition period
to clarify the implementation.
Scientists and engineers from
around the world, together with
industry partners, are participating
in the SKA project which is driving
technology development in antennas,
data transport, software and computing, and power. The influence of the
SKA project extends beyond radio
astronomy. The design, construction
and operation of the SKA have the
potential to impact skills development, employment and economic
growth in science, engineering and
associated industries, not only in
the host countries but in all partner
countries.
A further vote of confidence in the
ASKAP is the fact that the SKA project
also plans to invest in it by adding
more dishes.
Money well spent
The ASKAP has, and will continue
to provide, a solid base for Australia to
develop cutting-edge electronics and
computer technology, train engineers
and keep high-profile scientists in the
country where their expertise can help
budding scientists. In this regard, the
money is well spent, despite the decision regarding the SKA.
Looking further afield, data from
the ASKAP and the SKA will be freely
available to all scientists, regardless of
which countries host the telescopes.
Researchers from anywhere will be
able to use this data to gain greater
insights into the cosmos and have the
opportunity to make great discoveries
that will benefit all of humanity. SC
siliconchip.com.au
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