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October 2010
In this issue
Innovative new design for SA's MeerKAT
New measurements of radio frequency interference at the proposed South African and Australian SKA sites
Africa unites behind continent's SKA bid
IAU Astronomy Development Office will be in South Africa
Global partnerships to meet SKA demands
Developing skills for the future
SKA Africa boosts maths and science at nearby schools
Northern Cape communities gear up to support Africa's SKA bid
HartRAO 26m radio telescope recommissioned
Houwteq Anechoic Room Facility
Updated branding for SKA Africa
New home for SKA Africa in Cape Town

Innovative new design for SA's MeerKAT

Following an extensive engineering design process, the baseline design concept for the South African MeerKAT precursor telescope has been decided. This design process consisted of an in-depth design study that investigated implementation options and tradeoffs for all key subsystems, and culminated in a Concept Design Review (CoDR) undertaken by an independent panel of international experts. The recommendations of the CoDR panel have informed the baseline concept, and the most visible design decision is that the MeerKAT will consist of 64 Gregorian offset dishes, each with an effective diameter of 13.5 metres.

The MeerKAT concept design review panel met from 5 - 8 July 2010 in Cape Town. Pictured here are (fltr) Dr Peter Dewdney (SPDO), Prof Wim Brouw (Chair, Groningen), Dr Robert Laing (ESO), Anita Loots (SKA Africa), Dr Peter Napier (NRAO), Dr Bernie Fanaroff (SKA South Africa Project Director), Prof Roy Booth (HartRAO), Dr Marco de Vos (ASTRON) and Prof Justin Jonas (SKA Africa / Rhodes University). Dr Simon Garrington (Manchester) and Dr Yashwant Gupta (TIFR) also took part, but could not attend the meeting in person.

"The overall impression of the state of the project was very positive and the review panel noted that in several instances, the technical development for KAT-7 produced unique new technical knowledge." - Report of the International panel for the MeerKAT Concept Design Review, 5 - 8 July 2010

An offset dish configuration has been chosen because its unblocked aperture provides uncompromised optical performance and sensitivity, excellent imaging quality, and good rejection of unwanted radio frequency interference (RFI) from satellites and terrestrial transmitters. The offset optical configuration also facilitates the installation of multiple receiver systems in the primary and secondary focal areas, and is the reference design for the mid-band SKA concept.

"This is the most innovative option of the design solutions that we considered, but it will allow the MeerKAT to operate at a sensitivity of over 220 m²/K" explains Anita Loots, Associate Director of the SKA South Africa Project.

With all seven dishes of the MeerKAT precursor array (known as KAT-7) now in place, the construction of MeerKAT itself is the next big step for the SKA Africa team. "We will start by building a qualification (prototype) dish of the new design, on site in the Karoo," Loots adds. This first dish will be located near the KAT-7 array, which will allow extensive testing of the performance of the new design against the existing array. This work will inform the international SKA Dish Verification Programme (DVP), an important component of the PrepSKA study and the international SKA pre-construction phase.

The new design of the dishes of South Africa's MeerKAT telescope is in line with the kind of dish likely to make up the Square Kilometre Array (SKA) mid-band instrument.

"The completed KAT-7 array is an important engineering test-bed for technologies and systems for MeerKAT, but it will also be used to do science. We have already received several requests from radio astronomers around the globe who want to use it as a science instrument." explains Professor Justin Jonas, SKA Africa's Associate Director for Science and Engineering. The commissioning of KAT-7 is led by Dr Debra Shepherd, currently on secondment to SKA South Africa from the National Radio Astronomy Observatory in the USA. It is expected that KAT-7 will be ready to do science early in 2011, while MeerKAT should be operational by 2015.

The MeerKAT sub-systems employ a number of novel technologies which are in the mainstream of SKA development. The MeerKAT design process will provide important deliverables for the SKA South Africa Project, as expected from the precursor instruments. In addition to the pioneering use of composite materials for the dish reflector surfaces and structural components (KAT-7 is the world's first radio telescope with dishes made of fibre glass), design challenges include the development of very wide band waveguide feeds and receivers, low-cost cryogenic systems for cooling the receivers, direct digital sampling systems, high speed digital signal processing systems, algorithms for astronomy data processing, high performance computing platforms that match the algorithms, and very fast data transport networks.

Looking forward to MeerKAT science

Towards the end of 2009, the SKA South Africa Project invited the international astronomy community to submit proposals for science with MeerKAT. Twenty-one proposals for large science projects were submitted by multi-national teams, including about 500 international astronomers and 58 based in Africa. The proposals cover large and deep surveys of neutral hydrogen, the continuum sky, pulsars and molecular lines. An announcement on the prioritisation of these proposals has been made by a Time Allocation Committee (TAC) comprised of South African and international astronomers. All of the proposals are linked to SKA science topics, and the science goals include pulsar timing and tests of general relativity, the evolution of galaxies and the nature of cosmic magnetic fields.

MeerKAT milestones

20 July 2009
First antenna for KAT-7, an engineering test bed for the Karoo Array Telescope (MeerKAT), installed on site in the Karoo.

3 December 2009
Interference fringes seen between two of the dishes which have been constructed on the MeerKAT site.

10 February 2010
All seven KAT-7 dishes in place, but not yet fully operational.

15 March 2010
Twenty-one proposals for MeerKAT science received in response to a request for proposals to the scientific community.

30 March 2010
South Africa's Minister for Science and Technology and the Premier of the Northern Cape visit KAT-7 in the Karoo. Seven dishes installed, with four dishes operational.

10 May 2010
Four KAT-7 antennas linked together as an integrated system to produce the MeerKAT's first interferometric image of an astronomical object. View the press release and images

5 - 8 July 2010
MeerKAT Concept Design Review Panel meets in Cape Town to review the options presented by the technical team in order to define MeerKAT. The outcome of this meeting was very positive, with the panel validating recommendations from the team.

14 September 2010
Conclusion of a month-long radio frequency interference testing campaign at South Africa's proposed Karoo site.

20-22 September 2010
MeerKAT Time Allocation Committe meeting to rank the large survey proposals.

20 October 2010
First "cold" receiver (i.e. receiver with low noise amplifier and ortho-mode transducer that are cryogenically cooled) scheduled to be installed in the Karoo on one of the KAT-7 dishes.