First Instant World Telescope Views Distant Galaxy

SYDNEY, Australia, September 5, 2007 (ENS) - For the first time, radio telescopes in Australia, China and Europe have been linked in real-time, in effect creating a telescope almost as big as the Earth.

Last week, a telescope near Coonabarabran, New South Wales operated by the Australian government research agency CSIRO was used simultaneously with one near Shanghai, China, and five in Europe. The linked telescopes all observed a remote galaxy called 3C273.

Map shows the locations of the telescopes in the first instant world telescope demonstration on August 28, 2007. (Map courtesy EXPReS)

"This is the first time we've been able to instantaneously connect telescopes half a world apart," said Dr. Tasso Tzioumis, with CSIRO's Australia Telescope National Facility.

"It's a fantastic technical achievement, and a tribute to the ability of the network providers to work together," he said.

Data from the telescopes was streamed around the world at a rate of 256 Mb per second - about 10 times faster than the fastest broadband speeds available to Australian households - to a research center in Europe, where it was processed with a special-purpose digital processor.

To demonstrate the instant world telescope, the data results were transmitted to Xi'an, China, where they were watched live by experts in advanced networking at the 24th Asia-Pacific Advanced Network, APAN meeting.

From Australia to Europe, the CSIRO data travelled on a dedicated high capacity one gigabyte, 1Gb, per second link set up by the Australian Academic Research Network, AARNet, the Canadian research and education network CANARIE, and the Dutch SURFnet.

China's Sheshan telescope near Shanghai. (Photo courtesy e-VBLI)

The more widely separated the telescopes, the more finely detailed the observations can be.

"The diameter of the Earth is 12,750 kilometers and the two most widely separated telescopes in our experiment were 12,304 km apart, in a straight line," Dr. Tzioumis said.

CSIRO's Mopra telescope near Coonabarabran NSW (Photo by Shaun Amy courtesy CSIRO)

The telescope linking technique, called very long baseline interferometry, used to take weeks or months.

"We used to record data on tapes or disks at each telescope, along with time signals from atomic clocks. The tapes or disks would then be shipped to a central processing facility to be combined," Dr. Tzioumis said.

The technique allows observations of an object that are made simultaneously by many telescopes to be combined, simulatng a telescope with a size equal to the maximum separation between the telescopes.

The institutions that took part in the experiment are all collaborators in the EXPReS project, known formally as the Express Production Real-time e-VLBI Service.

"This is a fantastic achievement," said Huib van Langevelde, director of JIVE, who was present at the APAN meeting in China. "When we started doing e-VLBI we wondered whether we would ever be able to connect to these far-away telescopes, because there are not only various oceans to cross but also many different network providers."

The major activity of JIVE has been the development, construction and successful operation of a powerful supercomputer that combines the signals from radio telescopes located across the planet, creating a single virtual telescope of intercontinental dimensions.

Arpad Szomoru, head of R&D at JIVE, said, "We have recently developed and implemented various solutions that allow us to stream data over these enormous distances that overcome the problems with long round trip times."

Additional tests with telescopes in Puerto Rico and Chile are planned for the near future.

EXPReS aims to implement up to 16 simultaneous 1 Gb per second network connections between the central processor at JIVE and partner telescopes across Europe, Asia, Australia, South Africa, South America and the United States by 2009.

Copyright Environment News Service (ENS) 2007. All rights reserved.