Together with Australia, China and Argentina, South Africa is on the
shortlist to host the world's largest radio telescope, the Square Kilometre
Array, or SKA. "Competition in this bid is tough, as the winning country
will attract a billion Euro investment and one of the most ambitious science
projects ever," says Dr Bernie Fanaroff, South Africa's SKA Project
Manager. "The winner in the SKA bid will only be known by 2008, but in the
mean time we are planning to build the Karoo Array Telescope, or KAT, in the
same region where we hope to site the core of the SKA."
The KAT will have about 1% of the SKA's receiving capacity, but it will still
be a powerful radio telescope in its own right. It will also prove that South
Africa is committed and ready to host the SKA. Alongside the new Southern
African Large Telescope (SALT), KAT will further boost South Africa's profile as
a premier astronomy destination. "Our government recognizes the power of
astronomy as a tool to put South African science on the world stage and to boost
development within the country," Dr Fanaroff adds.
A radio telescope has to be as far away as possible from man-made sources of
radio waves. For months the SKA team worked closely with the Independent
Communications Authority of South Africa (ICASA) to measure radio frequency
interference (RFI) levels in some of the most remote parts of South Africa as
part of the process to find the best place to build the telescope. They have
identified three sites in radio quiet valleys in the Karoo, where surrounding
mountains provide extra shielding against radio waves from metropolitan areas.
The team will select the final site after even more RFI results and
infrastructure costs have been compared. "The challenge is to find the best
balance between science benefits and investment."
According to Dr Fanaroff, KAT must perform first light experiments by the end
of 2009. "To achieve this, we have to move the first dishes for the full
20-dish KAT array, onto site by May 2008," he says. "By then the basic
infrastructure, such as roads, electricity, water and sewage must also be in
place." The KAT team and other contractors around the country are working
towards these deadlines. While some are developing the sophisticated software
and digital signal processing hardware and firmware, others are doing research
to develop state-of-the-art receiver and feed systems, designing the dishes or
refining the work on the selection on the physical site. The KAT software will
evolve through a series of prototypes, starting with the Production Equivalent
Demonstrator ("PED") to be tested at the South African Astronomical
Observatory (SAAO) in Cape Town.
A single 15 m prototype dish to test feeds, signal processing equipment and
software will be built by IST Dynamics (Pty) Ltd at the Hartebeesthoek Radio
Astronomy Observatory (HartRAO). "This dish will not only be the test bed
for all KAT components, but it will also strengthen our industry's capacity to
design and construct large dishes," says Anita Loots, KAT Project Manager.
"This will make it possible for South African industry to compete for
contracts on SKA." The KAT prototype has to be ready by mid 2007.
According to Kim de Boer at the SKA project office in Johannesburg, there
will be many opportunities for postgraduate students to get involved in the KAT
project. "KAT will be commissioned in phases and along the way we expect
many exciting research opportunities to open up," she says.
The KAT team is working closely with radio astronomy teams in Australia, the
UK, Netherlands and the USA. "Our collaboration with international partners
will greatly reduce the cost and risks of building KAT," says Dr Fanaroff.
KAT enjoys the support of several local research organizations and government
departments, but the team is also working hard on finding more funding partners
to make KAT a truly world class instrument. The project operates under the
auspices of the Department of Science and Technology.