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Our Research

Data/Phase signal transport


A video produced by EuroNews about e-VLBI's role in the next generation of radio astronomy.

Jodrell Bank has concentrated in recent year on the development of e-VLBI, where signals from radio telescopes are sent to a central processor by the internet, rather than using disks shipped across the world. Initial steps were made by the PPARC/EPSRC funded project ESLEA (Exploitation of Switched Lightpaths for E-science Applications) which finished in 2007. This demonstrated that high data rates (up to 1 Gbits per second could be sent through the academic network structure (JANET in the UK and SURFNet in the Netherlands and later GÉANT) to the European correlator in JIVE in the Netherlands. Further developments of e-VLBI have been funded by the EU in EXPReS (Express Production Real-time e-VLBI Service). This project finishes in July 2009, where the technique is made routine for astronomers using the VLBI network.

The specific projects at Jodrell Bank are:

  1. To enable multiple MERLIN telescopes to be added to the VLBI array. This relies on being able to interface to the MERLIN system, and the provision of adequate bandwidth through national and international networks to JIVE.
  2. To investigate the performance of a variety of protocols in high bandwidth long distance networks with particular reference to e-VLBI,
  3. To connect the Onsala telescope in Sweden to Jodrell Bank at 4 Gbps, in order to make test observations with MERLIN telescopes using the new e-MERLIN correlator currently under construction

1) and 3) above make extensive use of the internet Breakout Board (IBOB) developed by the University of Berkeley, which has been programmed by us to transmit and receive 10 GE data across the academic networks. The IBOBs can be used as network testers with low jitter.

Jodrell Bank astronomers were the first to obtain published results using e-VLBI techniques on the microquasars GRS1915+105 and Cygnus X-3.

(NB pictures available)

Meetings and workshops

We hold regular (monthly) internal meetings at Jodrell Bank. In addition we held e-VLBI Bits and Bytes meetings in 2006: in August at University College, London, and in Manchester in November, funded by ESLEA not EXPReS.

Attendees at the FABRIC Kick-Off meeting, Dwingeloo, 6 March 2006 were R. Spencer, R. Hughes-Jones, B. Anderson

Attendees at the FABRIC meeting Poznan 25 Sept 2006 were P. Burgess, R. Hughes-Jones

Attendees at the NREN meeting and Expres kick off meeting, Zaandam, 30 Nov 2006 were P. Burgess, R. Hughes-Jones, R. Spencer

Attendee at the EXPReS Board meeting 1 Nov 2006: R. Spencer

Manchester eVLBI Bits and Bytes meeting 8 Dec 2006: J. Hargreaves (other staff were covered by ESLEA funds)

27-29 March 2007 Xilinx XPS/EDK training, Bournemouth UK (JH) 2 day training course on Xilinx embedded systems development kit. The Casper IBOB toolflow is based on this software.

22-24 April 2007 Digital Back end development meeting, Bologna. (JH).

21-24 May 2007 TERENA Network meeting Copenhagen (RHJ) Presentations: "The Performance of High Throughput Data Flows for e-VLBI in Europe: Multiple vlbi_udp Flows, Constant Bit-Rate over TCP & Multi-Gigabit over GEANT2" Richard Hughes-Jones.

27-29 May 2007 EXPReS board and NREN forum (RES)

12-13 June Meeting with NORDUnet and SUNET to discuss network for Fabric tests (RHJ)

23-30 June 2007, Casper IBOB Workshop, Berkeley California, USA (JH) Week long training on using the IBOB tools and libraries, future development of the tools and the IBOB II

18-21 September 2007, 6th International eVLBI meeting, Bonn, Germany (JH, RES, RHJ, PB) Presentations on IBOB developments at Jodrell

7 Nov 2007 JANET Optical Networking meeting (RES)

17-18 December 2007 Bits & Bytes Meeting, Jodrell Bank Observatory UK (JH, RES, RHJ, PB, SC). Presentation and hands-on demonstration on our experiences with the IBOB tools and libraries. (see http://www.jb.man.ac.uk/~res/BitsandBytes.html )

January 29/30 2008 EXPrES Progress and Board Meeting Utrecht (RES, RHJ) Presentations on progress at Jodrell Bank on FABRIC and on 4 GBps network tests.

List of publications

List of Presentations

Papers presented by staff from Jodrell Bank and elsewhere contributing to EXPReS:

Astronomy with e-VLBI:

Presentations and Publications ESLEA Closing Conference 26-28 March 2007, Edinburgh: