ORIENT and GÉANT2 Link the World’s Largest Telescope
Press Release
“A major technical achievement”: Huib van Langevelde, director of JIVE
Radio Astronomers from Europe and China have for the first time used the trans-Siberian ORIENT circuit to connect telescopes thousands of miles apart, demonstrating what can be described as the world’s largest telescope.
The ORIENT circuit linking together Chinese networks, CERNET and CSTnet, and the European GÉANT2 network and its Dutch partner SURFnet, allowed high speed transfers of astronomical data from a Chinese telescope to a supercomputer in the Netherlands. The use of ORIENT not only brings high network capacity, but also, by using the most direct route possible from China to Europe, reduces the time taken by the data to reach Europe by half compared with trans-Pacific routes.
Collaborators in the EXPReS project (Express Production Real-time e-VLBI Service) conducted the first successful e-VLBI observations to jointly use telescopes in China and Australia, China and Europe, and for a brief period Australia and Europe. The observations were demonstrated today by the Joint Institute for VLBI in Europe (JIVE), in partnership with their European VLBI Network (EVN) colleagues in Europe, China and Australia, to advanced networking experts at the 24th APAN (Asia-Pacific Advanced Network) Meeting in Xi'An, China.
e-VLBI, or real-time, electronic very long baseline interferometry, is a technique by which widely separated radio telescopes simultaneously observe the same region of sky, and data from each telescope are sent in real-time to a central correlator via high-speed communication networks. The correlator is a purpose-built supercomputer which analyzes the data to allow researchers to map the sky. The correlator can produce data with up to one hundred times better resolution than the best optical telescopes. In other words, this technique creates a virtual single telescope with an observing area equal to the distances separating the actual telescopes.
When data from the telescopes are sent electronically via fibre optic network, they can be correlated in real-time by the central processor at JIVE. This technique, known as e-VLBI, is ideally suited to observations of transient events such as supernova explosions and gamma-ray bursts. Astronomers receive data quickly and can plan follow-on observations accordingly. This is an improvement on the traditional VLBI process of shipping hard drives to the correlator, which can take weeks for delivery alone.
In preparation for today's demonstration, data were recently obtained using European, Australian and Chinese telescopes in separate tests. Today's demonstration, however, provided the first real-time correlation results from China-Australia, China-Europe and Australia-Europe baselines.
The observations were conducted by JIVE staff members in collaboration with their European VLBI Network (EVN) partners in Europe, China and Australia. Participating radio telescopes included the Mopra and Sheshan telescopes during the Chinese-Australian part of the experiment, and the Sheshan, Darnhall, Jodrell Bank, Medicina, Torun and Westerbork telescopes in the European-Chinese part.
Data were transferred to JIVE at a rate of 256 Mbps per telescope. Mopra was connected directly to JIVE through a dedicated 1-Gbps lightpath set up by the Australian, Canadian and Dutch national research and education networks (NRENs) AARNet, CANARIE and SURFnet, respectively. The Sheshan telescope was for the first time connected via the Chinese NRENs CSTNET and CERNET, the new high speed route across Siberia provided by the EC-sponsored ORIENT and TEIN2 networks, the pan-European GÉANT2 network and finally SURFNet. Most of the European telescopes have been connected for some time via dedicated lightpaths provided by the GÉANT2 partners.
"Getting this connectivity was not only a major technical achievement. It shows how a project like EXPReS can achieve things even beyond EC boundaries," said Huib van Langevelde, director of JIVE, an international institute to which the National Astronomical Observatory of China directly contributes.
Additional tests with telescopes in Puerto Rico and Chile are planned for the near future. EXPReS aims to implement up to 16 simultaneous 1 Gbps-network connections between the central processor at JIVE and partner telescopes across Europe, Asia, Australia, South Africa, South America and the USA by 2009.
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). The major activity has been the development, construction and successful operation of the EVN Data Processor, a powerful supercomputer that combines the signals from radio telescopes located across the planet, creating a single virtual telescope of intercontinental dimensions. Using this technique of 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.
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 distributed, large-scale astronomical instrument of continental and intercontinental dimensions. This electronic Very Long Baseline Interferometer (e-VLBI) is achieved using high-speed communication networks operating in real-time and connecting together some of the largest and most sensitive radio telescopes on the planet. EXPReS is coordinated by JIVE, the Joint Institute for VLBI in Europe, which is hosted by ASTRON, the Netherlands Foundation for Research in Astronomy, in Dwingeloo.
About GÉANT2
GÉANT2 delivers the next generation research and education network for Europe. With over 30 million research and education users in 34 countries across the continent, GÉANT2 offers unrivalled geographical coverage, high bandwidth, innovative hybrid networking technology and a range of user-focused services. Its network extends more than 50,000 km and its extensive geographical reach interconnects with other world regions, enabling global research collaboration. GÉANT2 is co-funded by the European Commission under the Sixth Research and Development Framework Programme. The project partners are 30 European National Research and Education Networks (NRENs), TERENA and DANTE. For more information visit http://www.geant2.net
Participating astronomy institutes and telescopes:
- CSIRO Australia Telescope National Facility (Mopra telescope) - www.atnf.csiro.au
- Institute of Radioastronomy, National Institute for Astrophysics (Medicina telescope) - www.ira.cnr.it
- Jodrell Bank Observatory (Darnhall and MkII telescopes) - www.jb.man.ac.uk
- Netherlands Foundation for Research in Astronomy (Westerbork telescope) - www.astron.nl
- Shanghai Astronomical Observatory, Chinese Academy of Sciences - center.shao.ac.cn center.shao.ac.cn (English center.shao.ac.cn/english.htm)
- Torun Centre for Astronomy, Nicolaus Copernicus University (Torun telescope) - www.astro.uni.torun.pl
(English www.astro.uni.torun.pl/eng/index.php)
Participating network organizations:
- AARNet - www.aarnet.edu.au
- CANARIE - www.canarie.ca
- CENIC - www.cenic.org
- CERNET - www.edu.cn (English www.edu.cn/english_1369)
- CSTNET - www.cstnet.net.cn (English www.cstnet.net.cn/english)
- DANTE (ORIENT, TEIN2 and GÉANT2 networks) - www.dante.net
- GARR - www.garr.it (English www.garr.it/garr-b-home-engl.shtml)
- JANET - www.ja.net
- PIONIER - www.pionier.gov.pl (English www.pionier.gov.pl/eindex.html)
- Southern Cross Cable Network - www.southerncrosscables.com
- SURFnet - www.surfnet.nl (English www.surfnet.nl/info/en)


