All astronomical objects in the universe send out radio waves – which can be compared to the white noise or “snow” you can see and hear on a television that needs to be tuned in. Scientists are collecting these signals with massive radio telescopes (some of which resemble large satellite dishes), and sending the data to super-computers, where it is processed it into high-quality images of galaxies and other objects in the universe.
In South Africa, this information is being gathered by MeerKAT, the southern hemisphere’s biggest and most sensitive radio telescope, which will later feed into the Square Kilometre Array (SKA), the world’s biggest science project, which will have sites in Africa and Australia.
MeerKAT currently has 16 working radio telescopes in a remote area of the Northern Cape – placed far away from human activity and cell phone signals – but the plan is to expand it to 64 by 2017. These will feed into SKA in Africa, which by 2024 will have 3000 radio telescopes spiralling out across the continent.
DESERT EARS … Massive radio telescopes gather information at MeerKAT, which will later feed into the Square Kilometre Array (SKA). (Source: www.ska.ac.za)
“The idea behind SKA is that if you had one telescope looking at the sky, you would get information [it would likely record a weak signal from space]. But if you have two or three, the information will be better. If you cover the whole of the African continent with radio telescopes, even better,” explained Prof Tim Gibbon, director of Nelson Mandela University’s Centre for Broadband Communication, one of a number of global role players ensuring this highly-specialised big-data project operates smoothly.
“Each radio telescope performs observations in the sky – collecting up to 160 gigabytes of data per second – and each sends this data to a super computer, which correlates and combines all the images into the equivalent of one overall high quality scientific snapshot.”
SKA, with thousands of radio antennae, will be powerful enough to detect radio waves from objects millions or even billions of light years away from Earth – and will enable astronomers to probe the universe in unprecedented detail.
“By 2020, the SKA telescopes will be collecting over 100 times all the data in the worldwide internet.”
And this is where Prof Gibbon and his team are involved, having already started working together with the SKA-South Africa organization on MeerKAT.
“Mandela University is playing a role in two areas. The first is to aggregate huge amounts of data to a central computer. All the telescopes need to be synchronised – with the central computer equipped to take measurements in a synchronised way.” The second area is the dissemination of extremely accurate timing signals from the central computer to the different radio telescopes. “This is extremely sensitive to the movement of optical fibre and temperature changes.”
The Centre’s work has led to a partnership with Cisco, which has provided R50m worth of equipment. They are also supported by the Department of Science and Technology and the Council for Scientific and Industrial Research’s (CSIR’s) Meraka Institute.
SKA South Africa has also been good to us, giving us bursaries for our students and funding for exciting research,” said Gibbon. Mandela University PhD graduate Romeo Gamathan is also employed by SKA South Africa.
Ten member countries are working on the SKA project, although some 100 organisations from 20 countries have been participating in its design and development.
The Centre for Broadband Communication is also involved in several other key projects, focusing mainly on high-speed optical fibre telecommunications. “These projects are to do with technologies that make the internet faster and more efficient.”
They include “Fibre-to-the-Hut”, an adapted-for-Africa variation of Europe’s “Fibre-to-the-Home” project, which aims to enable high speed internet access for all (via huge optical fibre data pipes). Another project is looking at network intelligence, where a network will “heal or optimise itself” if there is a problem. For instance, if there is a break in the network link, it will reroute the data traffic, finding a better link elsewhere. Or, if someone wants to send large amounts of data over a long distance, the network will choose the optimum path.
For these projects, the Centre is working closely with industry, including Telkom, Dartcom SA, Lambda Test Equipment and Cisco.
Gibbon, a C2-rated researcher with 70 published journal articles, obtained his PhD from Nelson Mandela University in 2007, and then worked at the Technical University of Denmark before returning to the University as a researcher and lecturer.
“In Denmark, everyone has a very fast internet. They all have optical fibre coming to the home, with high speed internet of 1GB/s. You can download a DVD in seconds … Between cities, there are huge optical fibre data pipes.” In Denmark, he was developing next-generation Fibre-to-the-Home systems for Europe.
Gibbon has supervised six PhD and five master’s students.
He said 50% of the students involved in the Centre are from other African countries. After they graduate, they maintain strong links the Centre, with Gibbon helping them to implement their specialised skills in their home countries, particularly as entrepreneurs. “We run industry training workshops where we help to train local people, and we also help them with access to equipment.”