KAT takes shape

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The first Karoo Array Telescope (KAT) dish is set to commission in August at a site near Carnarvon in the Northern Cape.

KAT is a seven-dish radio telescope under construction in an astronomical reserve in the Karoo as a precursor to the 80-dish R900 million Meerkat and the internationally-funded 3000 to 5000-dish €1.5 billion Square Kilometre Array (SKA).

“The first fully tested and commissioned antenna will be handed over to SKA South Africa by contractor BAE Systems in early August,” the SKA South Africa Project office says in its latest update.

The project office says the antenna pedestals of the seven KAT antennas are currently being delivered to the site, as are components manufactured offsite for fitting to the antenna dishes.

The 4.5mt dishes themselves are to be built at Klerefontein, 78km from Carnarvon, where a construction shed, housing a 12m-diameter dish mould, has been completed. The dish mould, too, is in its final stages of completion.

A trailer has been custom built for the purpose of transporting the completed dishes along a newly-built road from Klerefontein to the telescope site at Losberg, 6km away.

The foundations for the seven antennas are also complete.

A tender for grid power and overhead optical fibre has closed and a decision on the contractor is expected early next month. “The work will commence shortly after the contract has been awarded,” the update says.

A design and engineering services tender for MeerKAT has recently been advertised and the KAT-7 reticulation tender was advertised on June 5.

Renovations at the SKA South Africa Support Base, also at Klerefontein, are now also complete. Offices, workstations, a mechanical laboratory, a boardroom and an indoor braai (barbecue) area are now available, the update advises.

Engineering update

The update adds that the design and development on the feed and cryogenic system have been completed. “The horn was tested at a testing range and actual vs. theoretical performance correlated very well. An innovative OMT (orthogonal mode transducer) design meant that weight budgets could be achieved.”

Design reviews for the Radio Front End (RFE) have been completed for all the “stages” of the system. “The next step is to get an integrated system in the lab to do performance testing prior to integrating with other subsystems or integrating in the Karoo. Tests at temperatures below what is expected in the Karoo (tested to 50K, while 70K is expected) proved that the Low Noise Amplifier, integrated with the cryogenic system, perform as predicted.”

SKA South Africa is collaborating with the University California at Berkeley to develop new hardware.

“In return for our contribution to the design work, the South African project will get a percentage of the boards once they have been manufactured. The hardware required for the first two working antennas (the so-called “fringe finder”) has been delivered and early testing on that has started.

“The aim is to test these boards on the GMRT during June/July 2009 prior to integrating them into the fringe finder system. In preparation for producing the boards for the KAT-7 hardware, the last manufacturing issues on the Digital Back End are currently being ironed out.”

“Since software is the ‘glue` that keeps the system together, the software group continually interacts with the rest of the technical team and scientists to ensure that the software will cater for everybody’s needs and will be what scientists expect.

“It is expected that a fully simulated system will be up and running by the end of June. The group has also been working on ways to process the large amounts of data from MeerKAT in real time and on simulations to predict performance from antennas based on their beam patterns and mount types,” the update notes.

SKA project head Dr Bernie Fanaroff has called the development the world`s largest IT project. The SKA will be built either in SA or Australia from 2013 and will start collecting data on the universe from 2018. The decision where to build it – near Carnarvon in SA or near Carnarvon in western Australia, will be taken by 2012.  

MeerKAT project leader Anita Loots previously told defenceWeb the SKA will have a data requirement similar to the Large Hadron Collider experiment at the European Organisation for Nuclear Research, better known as CERN.

Loots says the core of the SKA alone will require two computers capable of handling 10 petaflops each.

“As far as my knowledge goes, no proven petaflops machines exist in the world today, although the Japanese say they want to build one. So there’s still a lot to be done just to build the machines [we need to make SKA work].”

This data volume also dictates that the SKA have its own high-performance computing centre at Klerefontein.