What is EXPRe S EXPRe S Express Production

What is EXPRe. S? • EXPRe. S = Express Production Real-time e-VLBI Service • Three year project (March 2006 -2009) funded by the European Commission (DG-INFSO), Sixth Framework Programme, Contract #026642 EXPRe. S • Funded at 3. 9 million EUR • International collaboration: 19 radioastronomy institutes and research and education networks (NRENs) representing 14 countries on 6 continents • Objective: to create a distributed, large-scale astronomical instrument of continental and inter-continental dimensions • Means: high-speed communication networks operating in real-time and connecting some of the largest and most sensitive radio telescopes on the planet to the central correlator in the Netherlands PRESENTATION DATE EXPRe. S- TITLE OF YOUR PRESENTATION 1

EXPRe. S Partners 14 Countries, 6 Continents Radio Astronomy Institutes • Joint Institute for VLBI in Europe (Coordinator), The Netherlands • Arecibo Observatory, National Astronomy and Ionosphere Center, Cornell University, USA • Australia Telescope National Facility, a Division of CSIRO, Australia • Institute of Radioastronomy, National Institute for Astrophysics (INAF), Italy • Jodrell Bank Observatory, University of Manchester, United Kingdom • Max Planck Institute for Radio Astronomy (MPIf. R), Germany • Metsähovi Radio Observatory, Helsinki University of Technology (TKK), Finland • National Center of Geographical Information, National Geographic Institute (CNIG-IGN), Spain • Hartebeesthoek Radio Astronomy Observatory, National Research Foundation, South Africa • Netherlands Foundation for Research in Astronomy (ASTRON), NWO, The Netherlands • Onsala Space Observatory, Chalmers University of Technology, Sweden • Shanghai Astronomical Observatory, Chinese Academy of Sciences, China • Torun Centre for Astronomy, Nicolaus Copernicus University, Poland • Transportable Integrated Geodetic Observatory (TIGO), University of Concepción, Chile • Ventspils International Radio Astronomy Center, Ventspils University College, Latvia National Research and Education Networks (NRENs) • AARNet, Australia • DANTE, United Kingdom • Poznan Supercomputing and Networking Center, Poland • SURFnet, The Netherlands PRESENTATION DATE EXPRe. S- TITLE OF YOUR PRESENTATION 2

Participating Telescopes and Network Paths* *Logical network paths. PRESENTATION DATE EXPRe. S- TITLE OF YOUR PRESENTATION 3

EXPRe. S Network Diagram PRESENTATION DATE EXPRe. S- TITLE OF YOUR PRESENTATION 4

Activities # PC NA 1 NA 2 NA 3 NA 4 SA 1 SA 2 JRA 1 Description Leader Project Coordinator Huib Jan van Langevelde, JIVE Management of I 3 T. Charles Yun, JIVE EVN-NREN Forum John Chevers, DANTE e. VLBI Science Forum John Conway, Chalmers Public Outreach Kristine Yun, JIVE Production Services Arpad Szomoru, JIVE Network Provisioning Francisco Colomer, CNIG-IGN FABRIC Huib Jan van Langevelde, JIVE PRESENTATION DATE EXPRe. S- TITLE OF YOUR PRESENTATION 5

What is VLBI? • Astronomy technique: Very Long Baseline Interferometry • A radio telescope looks at an object in the sky and collects data to create an “image” of the source. • Multiple telescopes can view the same object simultaneously. The distance between the telescopes is the baseline. The baseline can be compared to building a single telescope with the diameter of this distance (sort of). • The resolution increases with additional telescopes and longer baselines. • The sensitivity of the image increases with the data collection rate at the telescope. • A central processor decodes, aligns and correlates the data for every possible telescope combination. • Result: images of cosmic radio sources with up to a hundred times better resolution than images from the best optical telescopes PRESENTATION DATE EXPRe. S- TITLE OF YOUR PRESENTATION 6

The science of e-VLBI Aperture Synthesis Imaging Image Credits: Avruch and Pogrebenko • A technique that uses a number of telescopes to simulate a much larger one. A larger dish, real or simulated, improves image clarity and brightness. This requires coordination between the telescopes and a supercomputer. Consider the examples displaying aperture size, aperture distribution and image quality. PRESENTATION DATE EXPRe. S- TITLE OF YOUR PRESENTATION 7

Interferometry Makes a Virtual Telescope PRESENTATION DATE EXPRe. S- TITLE OF YOUR PRESENTATION 8

What is the correlator? • Dedicated, purpose-designed and purpose-built hardware • Synthesis imaging simulates a very large telescope by measuring Fourier components of sky brightness on each baseline pair • Decodes, aligns and correlates the data for every possible telescope combination • EVN Mk. IV data processor at JIVE • custom silicon, 1024 chips • Input data is 1 Gb/s max • Around 100 T-operations/sec PRESENTATION DATE EXPRe. S- TITLE OF YOUR PRESENTATION 9

Interferometry PRESENTATION DATE EXPRe. S- TITLE OF YOUR PRESENTATION 10

What is e-VLBI? • Electronic VLBI • Instead of recording data and shipping disks to the central processor, immediately transport data over networks and correlate it in real-time. • Benefits: - eliminate weeks from the observation & correlation schedule - monitor problems in data collection - detect transient events and schedule near-immediate followon observations - automate observation PRESENTATION DATE EXPRe. S- TITLE OF YOUR PRESENTATION 11

Traditional VLBI vs. e-VLBI PRESENTATION DATE EXPRe. S- TITLE OF YOUR PRESENTATION 12