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Networks create 11,000km real-time virtual telescope

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  • From: "Kristine Yun" <>
  • To: <>
  • Subject: Networks create 11,000km real-time virtual telescope
  • Date: Mon, 26 May 2008 09:33:56 +0200


Networks create 11,000km real-time virtual telescope

Dwingeloo, the Netherlands (23 May 2008) - For the first time
yesterday, members of the EXPReS project (Express Production Real-time e
VLBI Service) simultaneously linked telescopes in Africa, Europe, North
America and South America to the central data correlator in the
Netherlands, simulating a telescope almost 11,000 kilometers in

Telescopes in Chile, Germany, Italy, the Netherlands, Puerto Rico,
South Africa and Sweden simultaneously observed quasar 3C454.3 and
additional targets and streamed data to the Joint Institute for VLBI in
Europe (JIVE). There the data was correlated in real-time, and results
were transmitted to Bruges, Belgium, as part of a live demonstration at
the TERENA Networking Conference 2008.

Arpad Szomoru, head of technical operations and R&D at JIVE, said,
"Connecting telescopes across such large distances across many different
domains poses some unique challenges. Transport via TCP/IP is not
suitable, but the use of UDP can cause serious disturbances in
connectivity for other users. For this demo we have applied a number of
methods, like the use of 1 Gbps lightpaths with guaranteed bandwidth,
VLANs and plain IP-routed connections. The success of this test
demonstrates that global e VLBI has become an operational reality."

Data from all seven telescopes was routed across numerous networks,
including: AtlanticWave, AMPATH, Centennial, DFN, G√ČANT2 (operated by
EXPReS project member DANTE), Internet2, Netherlight (operated by EXPReS
project member SURFnet), NGIX, RedCLARA, Reuna, SANReN, StarLight and

Using a technique called Very Long Baseline Interferometry (VLBI),
astronomers use multiple radio telescopes to simultaneously observe the
same region of sky. The data collected by each telescope is sampled,
synchronized and correlated for every possible pair of telescopes. Using
very widely distributed telescopes sampling data at very high rates,
this technique can generate images of cosmic radio sources with up to
one hundred times better resolution than images from the best optical

JIVE director Huib Jan van Langevelde noted the global reach of this
observation and e VLBI's contribution to science. "It is very
significant that we have shown that we can connect telescopes
distributed over all continents. Real-time connectivity between
telescopes at such distances is literally going to resolve the most
energetic radio sources in the universe."

EXPReS, a three-year projected funded by the European Commission, is
networking the telescopes to send the data electronically and correlate
it in real-time. Called e VLBI, this process eliminates the shipping of
disks and provides astronomers with correlated data in a timely fashion,
allowing them to exploit transient astronomical events such as
supernovae and gamma ray bursts. EXPReS aims to connect up to 16 of the
world's most powerful radio telescopes to the data correlator at JIVE
with an aggregate data flow of up to 16 Gbps by September 2009.

# # #

About EXPReS
Express Production Real-time e VLBI Service (EXPReS,
is a three-year project funded by the European Commission with the
objective of creating a real-time distributed astronomical instrument of
intercontinental dimensions. This electronic Very Long Baseline
Interferometer (e VLBI) is achieved using high-speed communication
networks and connecting together some of the largest and most sensitive
radio telescopes on the planet. EXPReS is a collaboration of 19 radio
astronomy institutes and national research networks in 14 countries and
is coordinated by the Joint Institute for VLBI in Europe (JIVE).

About JIVE
The Joint Institute for VLBI in Europe (JIVE, is a
scientific foundation with a mandate to support the operations of the
European VLBI Network (EVN). For this purpose it maintains, operates and
develops the MKIV EVN Data Processor, a powerful supercomputer that
combines the signals from radio telescopes located across the planet.
Through this technique, called Very Long Baseline Interferometry (VLBI),
astronomers can make detailed images of cosmic radio sources, providing
astronomers with the clearest, highest resolution view of some of the
most distant and energetic objects in the Universe.

Press release and images available online at

Arpad Szomoru, Head Technical Operations and R&D
Express Production Real-time e VLBI Service (EXPReS)
Joint Institute for VLBI in Europe
+31 521 596 509

Kristine Yun, Public Outreach Officer
Express Production Real-time e VLBI Service (EXPReS)
Joint Institute for VLBI in Europe
+31 521 596 543

  • Networks create 11,000km real-time virtual telescope, Kristine Yun, 05/26/2008

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