The Square Kilometre Array (SKA) could act as a catalyst for science, technology and engineering business opportunities, jobs and innovation, and has the potential to put Africa on the map as a world Big data and analytics hub.
The multi billion rand SKA, to be hosted in South Africa and Australia, will extend into eight African countries and will be the world’s biggest telescope. It is also one of the biggest-ever scientiﬁc projects and multinational collabo- rations in the name of science.
The radio telescope should be operationally mature by 2020.
With thousands of linked radio wave receptors in Australia and in southern Africa, the SKA radio telescope will constantly scan space and feed the data to astronomers around the world.
The amounts of data being collected and transmitted by the SKA in a single day would take nearly two million years to play back on an iPod. This means the project requires supercomputing power and Big Data management and analytics capabilities on an unprecedented scale. The SKA is working with the world’s most signiﬁcant ICT powerhouses on the project.
One aspect of the project will see the Netherlands Institute for Radio Astronomy and IBM collaborating to research extremely fast, but low-power exascale computer systems, data transport and storage processes, and streaming analytics that will be required to read, store and analyse all the raw data that will be collected daily.
The SKA project will also have unprecedented data connectivity needs. Meeting the advanced technological and engineering needs of this project will result in signiﬁcant local skills development, revolutionise science and technology research and enable innovative new businesses and employment in the science, technology and engineering ﬁelds.
Aside from the beneﬁts to African science, Big Data capabilities could be the biggest spin-off from the SKA project.
The innovations, skills development and commercial potential emerging as a result of the project are huge. The potential is not just academic – the taxpayer-funded IP is developed to a point where it is ready to become commercialised and beneﬁt the economy.
Human capital development is already taking place as a result of the SKA project, with bursaries and scholarships being granted to allow students to learn the necessary cutting-edge science, technology, maths and engineering skills to support the project. Because the SKA is a long-term project over decades, its effect will increase.
Going forward, there will be a strong drive to leverage the SKA as a spearhead for other programmes – including next generation high performance computing challenges and Big Data challenges.
Since 2005, the African SKA Human Capital Development Programme has awarded close to 400 grants for studies in astronomy and engineering from undergraduate to post-doctoral level, while also investing in training programmes for technicians.
Astronomy courses are also being implemented in other African countries, including Kenya, Mozambique, Madagascar and Mauritius. Career opportunities will increase substantially and new business opportunities will emerge.
Space Science supports the creation of an environment that is conducive to the implemen¬tation of the national space strategy and the South African earth observation strategy, which address the development of innovative applications and human capital to respond to national priorities.
Through SANSA, the country’s capacity to design, build, maintain and possibly even launch satellites is being developed. As part of the four-country African Resource Management Constellation, South Africa has begun work on the ZA-ARMC1 satellite; R232 million has been budgeted over the next three years for this project. This satellite will enhance Africa’s ability to monitor and manage its precious natural resources.
In January 2014, the DST paid the second tranche of the purchase price for satellite company Sunspace, bringing to an end the embattled company’s ordeal to pay creditors.
Sunspace’s employees moved to Denel, which has created a unit to host the intellectual property and capabilities, based in Stellenbosch.
Denel has since created Spaceteq, incorpo¬rating Sunspace, which aims to develop a multispectral, high-resolution Earth-observation satellite called EO-Sat1, for operation by 2017.
Information and Communications Technology
The DST is leading the implementation of the national ICT RDI Strategy. Its main purpose is to create an enabling environment for the advancement of ICT RDI in South Africa.
South Africa’s research capacity in the ICT field has become a strong competitive advantage.
The ICT RDI Strategy aims to achieve a marked increase in advanced human resource capacity, promote world-class research and build robust innovation chains for the creation of new high-tech ICT small enterprises. Implementing the strategy demands partnership involving government, the private sector, higher education institutions and science councils.
The Meraka Institute of the CSIR manages and coordinates the implementation of the strategy. An important envisaged outcome is a vibrant, sustainable and innovative indigenous ICT industry that addresses a significant portion of the country’s ICT needs and attracts investments by overseas-based multinational ICT corporations in RDI and manufacturing facilities and resources in South Africa.
The Centre for High-Performance Computing (CHPC), Sanren and the Very Large Databases are the three pillars of cyber-infrastructure that the DST supports. Hosted by the University of Cape Town and managed by the CSIR’s Meraka Institute, the CHPC was the first of its kind in South Africa and is making scientific supercom¬puting a reality for South Africa.
A major project for Sanren is the national backbone network, which aims to connect all major metros in the country with a 10 gigabyte per second link. On completion, the network will reach about 200 sites. The overall network architecture will consist of a national backbone connecting Durban, Pretoria, Johannesburg, Bloemfontein, Cape Town, Port Elizabeth and East London; with metro rings in Johannesburg, Tshwane, eThekwini and Cape Town.
Indigenous knowledge systems (IKS)
The Indigenous Knowledge System Policy serves as a guide for the recognition, understanding, integration and promotion of South Africa’s wealth of indigenous knowledge resources.
One of the areas of action identified by the policy is the protection of indigenous knowledge and the holders of such knowledge against exploitation.
This includes ensuring that communities receive fair and sustained recognition and, where appropriate, financial remuneration for the use of this knowledge
The indigenous knowledge of many commu-nities embodies a deeply spiritualised and ancient relationship with the Earth’s systems and cycles.
Traditional songs and languages, clothing, architecture, foods, motifs, daily rituals and myth-ological epics contain local survival information.
Moreover, the diversity of indigenous cultures provides unique insights into how to live harmoniously within nature.
By sharing indigenous stories of vulnerability and adaptation, people learn how communities share ideas on how ancestral wisdom is being incorporated into climatic adaptation strategies.
By cherishing the value of indigenous knowledge, people can discover how best to adapt to a changing climate.
The DST has three IKS priorities:
- The development of a regulatory environment for the protection of IKS.
- The development of the National Recordal System for the collection, recording, documenting, storage and management and dissemination of IKS in communities in the nine provinces of the country. Until orally transmitted and rapidly disappearing indigenous knowledge is recorded, it will be difficult to protect. The National Recordal System is the largest fingerprint initiative of the region to document and record indigenous knowledge.
- Applied research, specifically bioprospecting activities. An example would be how, with funding from the NRF, the MRC is developing the Moritela Tshwene Tea Project near Zeerust in North West, with the aim of producing a nutritional herbal tea for the commercial market.
The DST has put in place validation systems within its science system to ensure that indigenous knowledge products are safe and backed by the best science in the world.
To give further impetus to these critical initiatives, the department has set aside a dedicated fund to support research into indigenous knowledge.
Two indigenous knowledge research chairs have been awarded as part of the country’s Research Chairs Initiative (SARChI).
The DST also established indigenous know-ledge studies CoEs at the universities. The CoEs will play a defining role in generating highly qualified HR capacity in IKS.
South Africa’s gold-mining industry works at deeper levels and under more difficult conditions than any other mining industry in the world.
The research into gold mining conducted by the CSIR’s Mining Technology Group is concerned primarily with ensuring the health and safety of the workforce.
It includes those working in the areas of rock engineering and the underground environment.
Mining Technology’s coal-mining research takes place on a smaller scale than that of gold mining, because the coal-mining industry is able to make use of various developments overseas.
Areas in which research is undertaken include strata control, mining, maximising the extraction of coal, and the underground environment.
Research is also carried out by a large number of industrial companies with facilities to meet their specific needs.
The more important ones are the:
- Anglo American Corporation of South Africa (applied metallurgy, processing of precious metals, base metals and coal)
- Agricura (synthesis and testing of veterinary remedies, insecticides, herbicides and entomology)
- Cullinan Holdings (refractories and electrical porcelain)
- De Beers Industrial Diamond Division (manufacturing and application of synthetic diamonds and other super-hard material)
- Johannesburg Consolidated Investment Company (metallurgy, mineralogy, chemistry and chemical engineering)
- National Chemical Products (chemistry, microbiology and animal nutrition)
- Metal Box Company of South Africa (corrosion mechanisms and microbiology)
- Tellumat (develops electronic instruments)
- Rembrandt Group (develops and improves tobacco and liquor products)
- South African Pulp and Paper Industries (wood technology, paper manufacturing and water treatment)
- Standard Telephones and Cables South Africa (long-distance transmission of information and lightning protection).
South Africa has the world’s largest reserves of fluorspar, with estimated reserves of 41 million tons. They currently supply and estimated 10% of the fluoride requirements to R233,6 billion annual global fluorochemicals industry.
The DST’s Human-Capital and Science Platforms Subprogramme conceptualises, formulates and implements programmes aimed at developing and renewing science, engineering and technology human capital to promote knowledge generation, protection and exploitation.
South African universities train more and more scientists each year, with whose help the country will be able to spend R45 billion on research and development by 2014, thus reaching its target for gross expenditure on research and development of 1,5% of GDP.
Food security and access to clean water remain among government’s top priorities – the department is therefore also focusing on using science and technology to ensure that existing water supplies are clean and is playing an active role in ensuring food security into the future.
To this end, seven of the 60 new research chairs initiated by the department will serve the areas of rural development, food security and land reform, bringing the total of such chairs to 10.
International Cooperation and Resources
The DST is not only entrusted with the overall coordination of national research and innovation initiatives in South Africa, but is also responsible for overseeing and facilitating South Africa’s international scientific and technological cooperation.
The International Cooperation and Resources Programme’s purpose is to:
- Strategically develop, promote and manage international partnerships that strengthen the NSI
- Enable an exchange of knowledge, capacity and resources between South Africa and its international partners, with a focus on supporting science, technology and innovation capacity building in Africa
- Support South African foreign policy through science diplomacy
- Complement South Africa’s nationalinvestments in science technology and innovation, including access to resources for department initiatives that require external investment, by securing international funds of R1,4 billion by 31 March 2018
- Maintain the total number of researchers awarded research grants through NRF-managed programmes at 13 617 by the end of 2016
- Maintain the number of ISI-accredited research articles published by NRF-funded researchers at 21 000 in the period under review
- Strategically develop priority science areas in which South Africa enjoys a competitive advantage.
African Network on Drugs and Diagnostics Innovation (Andi)
Andi is based in Addis Ababa, Ethiopia, at the UN offices of the Economic Commission for Africa. Its board agreed that five regional hubs were to be created to support regional research initiatives, with South Africa offering to host the southern hub.
Andi evaluated African research initiatives on drugs and diagnostics, and identified 35 CoEs throughout Africa that were to receive priority attention. Fifteen of these are in South Africa.
All the centres are tasked with researching responses to the most intractable health burdens of the continent, from malaria and tuberculosis to river blindness. Many of these are diseases of the poor and invisible. Their researchers do not receive funding or intellectual support from established agencies – Andi’s aim is to reverse this.
It provides support to innovation in quality water provision that is community-led and -based through various agencies. It supported the development and use of new energy-efficient and attractive construction materials through the CSIR-led infrastructure innovation programme − 410 houses were built in Kleinmond, creating an integrated suburb.
It supports rural-based poverty alleviation initiatives in Limpopo, the Eastern Cape and KwaZulu-Natal. Another facet of Andi is the Ketlaphela/Lonza initiative that built a plant to manufacture active pharmaceutical ingredients for antiretroviral (ARV) production.
The departments of science and technology, trade and industry, economic development and health collaborated on this initiative to secure a significant proportion of the ARV market for local producers.
Women in Science Awards
Top South African women scientists were honoured at the Women in Science Awards ceremony held Johannesburg in August 2015.
The DST hosts these awards annually to reward outstanding female scientists and researchers, and encourage younger women to follow their example. The winners of the 2015 Women in Science Awards are as follow:
- Professor Maureen Coetzee – Distinguished Woman Scientist.
- Professor Marla Trindade – Distinguished Woman Scientist.
- Professor Lindiwe Zungu – Distinguished Woman Researcher.
- Dr Gina Ziervogel – Distinguished Woman Researcher.
Source: SA Yearbook 2015/16
- This groundbreaking project for world science will observe, capture and analyse radio signals from the immediate aftermath of the Big Bang. It will search for earth-like planets and potential life elsewhere in the universe, test fundamental scientific positions such as the theory of gravity, and probe the dark energy of the early universe.
- The SKA will see back to a time before the first stars lit up. Optical telescopes see the light from stars. Before stars existed there was only gas; a radio telescope with the sensitivity of the SKA can see back in time to the gas that existed before stars were even born.
- The SKA will have 3 000 dish antennas, each about 15 m in diameter, as well as two other types of radio wave receptor, know as low- and mid-frequency aperture array antennas. The mid-frequency aperture arrays will be built in South Africa and are envisaged to be a major component of the SKA Phase 2.
- The SKA will be 50 to 100 times more sensitive than any radio telescope built to date and will have an extensive array of approximately 3 000 antennae. Half of these will be concentrated in a central region of 5 km in diameter, and the rest will be distributed up to 3 000 km from this central concentration. Construction of the SKA is expected to begin in 2017 and conclude in 2024.
- The SKA will require the world’s fastest supercomputer and Internet connectivity to operate and will offer unparalleled scientific and business opportunities.
- The bid project was endorsed by the South African Cabinet in 2003 and is in line with the Government's Astronomy Geographic Advantage Programme (AGAP), which aims to establish a hub of world-class astronomy facilities in southern Africa.
- The project is led by the SKA Organisation, a not-for-profit company with its headquarters at Jodrell Bank Observatory, near Manchester, United Kingdom. The organisation was established in December 2011 to formalise relationships between the international partners and centralise the leadership of the project.
- SKA SA was established by the Department of Science and Technology of South Africa and is administered as a business unit of the National Research Foundation (NRF). The main programmes falling under SKA SA are the hosting of the SKA, the construction of the 64-dish SKA pre-cursor telescope known as MeerKAT, the establishment and protection of the Radio Astronomy Reserve in the Karoo region in South Africa, the development of a substantial human capital development program, and the development of the African VLBI Network.
The development impact
- Winning this mega astronomy infrastructure bid is expected to result in investment in Africa of about $2 billion in the continent during construction and $200 million per annum over a 20-30 year period. It will boost the development of high level skills and cutting edge technology infrastructure.
- The SKA will drive the development of internet connectivity in both rural and urban areas in Africa. A World Bank study concluded that every 10% increase in bandwidth connectivity for developing countries produces 1.3% growth in gross domestic product (GDP) of the host country.
- The SKA will attract the world's best scientists and engineers to work in Africa, and provide unrivalled opportunities for scientists and engineers from African countries to engage with transformational science and cutting-edge instrumentation, and to collaborate in joint projects with the most renowned universities and research institutions in the world.
- The location of the SKA in Africa will go beyond socio-economic development and will strengthen self belief and identity. If successful, the SKA Bid will strategically position Africa as a continent of choice for science and technology investments.
- As the United States (US) and other nations’ space programmes have done for decades, the SKA will expand the imaginations of people everywhere and raise the general appreciation for science and inspire the next generation.
- African Heads of State and Government endorsed South Africa’s bid to host the SKA at the African Union Summit in January 2010.
- At its meeting in Dakar, Senegal in January 2010, the African Physical Society (AfPS) ‘unequivocally’ endorsed the sitting of the SKA in Africa.
- Africa offers the astronomical "richness" of the southern skies and a strong tradition of astronomy. Possibly the oldest solar observatory was found at Nabta Playa in southern Egypt.
- South Africa’s Southern African Large Telescope (SALT) is the largest optical telescope in the Southern hemisphere. Moreover, Namibia has the High Energy Stereoscopic System (HESS) telescope, while several other African countries are constructing or refurbishing telescopes.
- Africa’s bid proposes that the core of the mega telescope be located in an arid area of the Northern Cape, with about three antenna stations in Namibia, four in Botswana and one each in Ghana, Kenya, Mozambique, Mauritius, Madagascar, Namibia and Zambia.
- Each antenna station will consist of about 30 individual antennae. The combined collecting area of all these antennae will add up to one square kilometre. These antennae will be connected via a data communications network to a very large and powerful data processing facility on the SKA site in the Northern Cape.
- The Karoo region of the Northern Cape is known for its topography, is sparsely populated and has a very dry climate. It geological profile is described as safe and stable with no seismic activity or natural disasters.
- South Africa's Astronomy Geographic Advantage Act of 2007 [PDF] declares the entire Northern Cape Province, with the exception of the Sol Plaatje Municipality (Kimberley) as an astronomy advantage area with strict regulations on radio frequency interference and 12.5 hectares around the core site protected as a radio astronomy reserve.
- In 2010 the proposed site was declared a national key point by the South African government.
- A site comparison by a University of Pretoria (UP) student, based on data from the National Aeronautics and Space Administration (NASA) AQUA Satellite recently indicated that the total water vapour content at the South African core site is 39% lower than the Australian core site.
- The total water vapour content has a negative effect on array radio telescopes like the SKA and the difference of 39% is considered significant. Cloud cover (which has a similar effect to reduction/loss of signal for satellite TV on a cloudy day) is similar for the two sites during half of the year but for the other half the cloud cover over the Australian site is higher.
- South Africa has excellent science and technology relations with the European Union (EU), and currently participates actively in the EU Framework Programme, including infrastructure projects. The US and the EU, which has invested millions in SKA research, will emerge as the main funders of the SKA.
- Construction of Africa’s SKA precursor telescope the Karoo Array Telescope (known as MeerKAT) is at an advanced stage to test possible technologies to be used in the ultimate design of the SKA itself.
- Once completed, MeerKAT will be the biggest radio telescope in the world until the completion of the SKA around 2023, meaning that South Africa will have 10 years of science that no one else will have.
- Three of the seven antennas of the KAT-7 demonstrator radio telescope outside Carnarvon in the Northern Cape province. The KAT-7 is paving the way for the 80-dish Karoo Array Telescope (also known as the MeerKAT), due to be commissioned in 2014/15 as a precursor to the SKA – and as one of the most powerful telescopes in the world in its own right (Photo: SKA South Africa)
- Five years before the MeerKAT telescope becomes operational, more than 43 000 hours of observing time (adding up to about five years) have already been allocated to radio astronomers from Africa and around the world, who have applied for time to do research with this unique and world-leading instrument.
- A preliminary design review (PDR) of the infrastructure for the MeerKAT telescope is currently being developed at the astronomy reserve in the Karoo region. The design is being developed with the first phase of the SKA in mind.
- The SKA South Africa project awarded the provision of the long-term MeerKAT and Southern Africa Large Telescope (SALT) 10 Gbps data link to InfraCO/Neotel. An interim 10 Mbps data link between the MeerKAT project office in Cape Town and the MeerKAT site went live on 19 January 2011 allowing for operation of the KAT-7 radio telescope to take place from the project's engineering headquarters in Cape Town.
- A team of technicians will be permanently on site at the KAT-7 telescope in the Karoo from 1 March 2011 to provide technical support during the roll-out and commissioning of the instrument.
- Tenders for the project are expected to be advertised during the third quarter of 2011 and construction is expected to commence by the end of 2011.
- South African engineers at the MeerKAT project office in Cape Town are taking the lead in the development of new generation astronomy tools such as the ROACH (reconfigurable open architecture computing hardware) boards in collaboration with UC Berkeley and National Radio Astronomy Observatory (NRAO).
- The ROACH board is a primary building block for digital signal processing systems in many next-generation radio telescopes for high-performance computing.
- A milestone has been achieved in South Africa with the successful detection of "fringes" in a joint very long baseline interferometry (VLBI) observation performed using one of the seven 12m dishes of the KAT-7 radio telescope, near Carnarvon together with the 26m dish of the Hartebeesthoek Radio Astronomy Observatory (HartRAO) near Pretoria
Benefits to the South African economy
- In South Africa the bid has already provided 800 construction job opportunities in the Northern Cape and will create a further 100 jobs this year.
- Government took a decision in 2004 to increase the number of PhD and MSc graduates in radio astronomy. The SKA’s Human Capital Development Programme (HCDP) was established deliberately to focus on developing highly scares skills required for the running and upkeep of the SKA.
- HCDP has spent nearly R42 million on capacity development in radio astronomy and the disciplines of engineering relevant to radio astronomy. From 2011 to 2014 the investment in capacity development will increase to about R50 million a year (an additional R200 million investment) and R35 million a year from 2015 to 2025 (a further boost of R350 million).
- The SKA Youth into Science and Engineering project has since 2005 awarded 293 bursaries to learners in various areas of astronomy. This includes 38 PhDs, 63 MScs and 15 postdoctoral fellowships. Grants have been made to 72 women and 39 students from other African countries. In addition, six research chairs have been established at South African universities.
- Support has been provided to 216 university lecturers and professors, postdoctoral fellows, postgraduate and undergraduate students, interns and engineering technician students and students from schools in the towns close to the South African SKA site.
- In addition to their participation in ‘blue skies’ scientific research, the young people supported by this programme will serve South Africa and Africa in key areas of economic development in the future. The bursaries have also created opportunities for studies in Astronomy at the University of Nairobi in Kenya and the Eduardo Mondlane University in Maputo in Mozambique. Madagascar and Botswana are planning to do the same and Mauritius is enhancing its existing Astronomy capacity.
- The number of professionals working in radio astronomy increased from 12 in 2003 to 54 in 2010. There are now also about 70 engineers, scientists and technicians in the project office working on the development and construction of the MeerKAT telescope.
- The South African SKA Project Office (SASPO) signed a formal collaboration agreement with the US National Radio Astronomy Observatory (NRAO) which will see the expansion of their staff exchange program and a outreach program to be associated with the Karoo radio astronomy reserve. The details of the collaboration will be finalised in the coming months, with the goal of signing an expanded memorandum of understanding in March 2011.
Benefits to communities surrounding the project site
- Undergraduate students with bursaries from the SKA South Africa Project regularly visit local communities in outreach programmes designed to excite learners of the Northern Cape about the leading role that their province is playing in the SKA.
- SKA Africa's schools outreach programme is equipping maths and science teachers in the area with new knowledge and skills, so that they will feel motivated, confident and inspired in teaching relevant subjects.
- As part of the outreach programme objectives, it aims to increase Grade 11 - 12 enrolments in maths and science, as well as to help learners achieve at least 60% in these subjects.
- A R750 000 grant from the Universal Service and Access Agency of South Africa (USAASA) have been used to build and equip a Cyberlab (computer centre) at Carnarvon High School. The lab is equipped with 43 desktop computers, a laptop, an interactive board and a printer.
- In towns like Carnavon and Williston lab equipment and computers are being provided to learners through a partnership between government and private sector sponsors.
- The US Embassy in Pretoria has donated books to the Carnarvon primary school.
- Aurora Private School, based in Johannesburg, invited 12 educators from Carnarvon and Williston to take part in an educational exchange programme to share best practices in science and mathematics education.
- The SKA South Africa Project has established stakeholder forums in the towns of Carnarvon, Williston and Van Wyksvlei to update communities on developments and benefits of the project.
Speeches and statements
- Science and Technology on Western Cape Big Data Centre SKA project, 25 May 2016
- Science and Technology on SA-German cooperation on MeerKAT, precursor of SKA project, 12 Nov 2015
- Minister Naledi Pandor: Signing Ceremony of National Research Foundation and Max Planck Society MoU on MeerKAT as precursor of SKA, 11 Nov 2015
- Science and Technology on land acquisition for SKA construction, 10 Nov 2015
- Minister Naledi Pandor: 2nd Ministerial Meeting of Square Kilometre Array African Partner Countries, 25 Mar 2015
- Science and Technology on conclusion of African Square Kilometre Array Ministerial meeting, 25 Mar 2015
- Minister Naledi Pandor on Square Kilometre Array project at BRICS meeting, 18 Mar 2015
- Science and Technology on Square Kilometre Array meeting in Manchester, UK, 10 Mar 2015
- Address by Deputy President Cyril Ramaphosa on the occasion of his visit to the site of the Square Kilometre Array Carnarvon, Northern Cape, 1 Mar 2015
- Deputy President Cyril Ramaphosa: Remarks during visit to Square Kilometre Array, 28 Feb 2015
- Square Kilometre Array benefits impress Committee, 27 Aug 2014
- Joint media statement on the outcomes of the First Ministerial Meeting of the Square Kilometre Array African Partner Countries 26 Mar 2014
- Minister Derek Hanekom welcomes UK contribution towards Square Kilometre Array, 11 Mar 2014
- Minister Derek Hanekom leads BRICS science Ministers on Square Kilometre Array site tour, 12 Feb 2014
- Address by His Excellency, President Jacob G Zuma on the occasion of the visit to the Square Kilometre Array (SKA) Site, Carnarvon, Northern Cape 9 Oct 2012
- Minister Naledi Pandor: Square Kilometre Array site decision, 25 May 2012
- First Ministerial meeting of the SKA African-partner countries, 26 Mar 2014
- President Zuma visits Square Kilometre Array site, 9 Oct 2012
- South Africa wins bid to co-host Square Kilometre Array, 25 May 2012
- Brochure on South Africa's proposal to host the Square Kilometre Array (SKA) [PDF]
- Square Kilometre Array