I've made some edits to the text already: strikethrough for deleted text and underline for added text.

In recent years, e-VLBI has evolved from an experimental technique, connecting a small number of telescopes in real-time at modest bandwidths, into an operational astronomical service with competitive sensitivity and imaging capabilities. In spite of its obvious advantages, this enhanced mode is not yet offered to all astronomers, due to connectivity, bandwidth and processing capacity limitations.

NEXPReS is addressing the shortcomings of e-VLBI, most importantly the inability to re-correlate data.

NEXPReS will introduce transparent buffering mechanisms at the telescopes and correlator. It will also address overcoming network failures or limited connectivity to essential stations, and eliminating the need for physical transport of magnetic storage media.

Additionally, NEXPReS will develop high-speed recording hardware as well as and software systems that manage the process and help to hide all the operational complexity. Real-time grid computing and dynamic bandwidth on demand will also be addressed to improve the continuous usage of the network and help prepare the EVN for higher bandwidths. With NEXPReS all astronomers using the network will benefit from the increased robustness and immediate feedback that e-VLBI offers. This NEXPReS will ensure it that the European VLBI Network (EVN) remains the most sensitive VLBI array in the world, while at the same time developing and testing new technologies to benefit the next generation of large array radio telescopes.

Cloud Correlation is transforming the complete VLBI observational chain and removing the current strict distinction between disk-based and electronic VLBI. The focus is the development of a system capable of simultaneous buffering, transmission and correlation of data to create a system in which all observations benefit from having a real-time component, while retaining the option to re-correlate the data at a later time.

High Bandwidth on Demand will transition upgrade operational connectivity from static to dynamically allocated connections, freeing up resources when there is no ongoing e-VLBI observation. Additionally, new on-demand paths should initially support at least 1024 Mbps operations, and eventually accommodate 10 Gbps observation rates and correlator capacity.

Computing in a Shared Infrastructure is creating an automated, distributed correlator using the global, shared infrastructure of the EVN and its partners. Tasks include: development of a transparent distributed correlation facility for VLBI surveys and monitoring programmes; conducting VLBI survey/monitoring test observations; and development of real-time stream processing on a shared computing infrastructure, eventually implementing distributed correlation and global correlation.

Provisioning High-Bandwidth, High-Capacity Networked Storage on Demand has two distinct aims with a common storage component. First, it will explore ways to implement on-demand networked storage that can match the multi-Gbps bandwidth and Petabyte-class capacity requirements of VLBI in a distributed manner. Second, it will address the use of such high-capacity storage systems for the data archives of the future, such as LOFAR and the SKA.

Improved Astronomical Capabilities
Improvements made by NEXPReS will benefit the entire VLBI user community. Astronomers will get better data quality, with more telescopes delivering good, error-free data for a larger fraction of the time. Additionally, the new system will allow more efficient use of the telescope infrastructure, resulting in more hours for science observations. Increased bandwidth and dynamic connection methods to new stations will result in greater sensitivity for the study of transient events and fainter objects, and to reach farther into the distant Universe. Re-correlation of data will make spectral line e-VLBI observations possible. Furthermore, improvements to the VLBI network are scientifically essential for complementing new telescopes such as EVLA, e-MERLIN, LOFAR and APERTIF. The high level of automation and inherently distributed architecture resulting from improved Grid computing and distributed data storage capabilities may be attractive to the Square Kilometre Array (SKA). Improvements to the technique will also strengthen European VLBI's important role in future planetary space missions.

[Image caption:]
Image: SN2007gr. Through a series of e-VLBI observations in 2007, astronomers for the first time ever detected relativistic outflow in a Type Ic supernova, supporting a link with even more energetic Gamma Ray Bursts. Their results were published in the 28 January 2010 issue of Nature. Credit: Paragi et al.]

Image: European VLBI Network e‑VLBI detection (colours) and follow‑up EVN+GBT observations (contours) of SN2007gr. This supernova belonged to a special class of type Ic, rarely observed with the VLBI technique. It has been suggested that the expansion speed well exceeded typical values observed in other type of supernovae. Paragi et al. 2010, Nature, Vol. 463, p. 516.

Improved Enhanced Research Infrastructure
Advancements made by NEXPReS will help give Europe a leading role further Europe's lead in long-haul, wide band connectivity, streaming computing and fast storage - critical resources for an enhanced research infrastructure for all scientific fields. Some of these solutions may be applicable beyond the scientific community, for example in dispatching large volumes of sensor data for weather or geodynamic monitoring.

Diverse Societal and Economic Benefits
Humanity carries out astronomical research primarily to satisfy its curiosity about the fate state of the Universe and the laws of physics that govern it. Astronomy has a great appeal to the general public and motivates young people to pursue careers in science and technology. The ways in which NEXPReS specifically will benefit society and economy are widely diverse. For example, it will make a significant contribution to Europe's leading role in radio instrumentation, strengthening its potential to build the SKA, estimated at 1.5 billion Euros participate in the construction of the SKA, a multi-billion euro global project. Additionally, the fast storage system could be commercially relevant, and the use of standard off-the-shelf components will make it attractive to both research/academic and commodity/industrial sectors.

Very Long Baseline Interferometry (VLBI) is an astronomical method by which multiple radio telescopes located hundreds or thousands of kilometres apart observe the same region of sky simultaneously. Data from each telescope is recorded onto hard disks which are and shipped to a central “correlator”, a purpose-built supercomputer which processes the data. This simulates a single telescope with a diameter as wide as the most distantly located telescopes and produces images with higher resolution than the most powerful optical telescopes.

Electronic VLBI (e-VLBI) improves upon the traditional disk-based method by streaming data directly from the telescopes and correlating it in real-time, currently at a rate of one Gigabit per second (Gbps) from each telescope, and eventually tens of Gbps. The speed of e-VLBI's speed allows personnel one to immediately identify and correct immediate identification and correction of problems during an observation, and delivers data to astronomers receive data in a matter of hours rather than weeks. If so-called transient activity is detected, such as a supernova or gamma-ray burst, the astronomer can quickly schedule additional observations, an advantage not possible with traditional VLBI.

Coordinator

• Joint Institute for VLBI in Europe (JIVE), EU (The Netherlands)

National Astronomy Institutes

• The Netherlands Institute for Radio Astronomy (ASTRON), The Netherlands
• Istituto Nazionale di Astrofisica (INAF), Italy
• Max Planck Gesellschaft zur Foerderung der Wissenschaften E.V. (MPG), Germany
• The University of Manchester (UMAN), United Kingdom
• Chalmers Tekniska Hoegskola AB (OSO), Sweden
• Ventspils Augstskola (VENT), Latvia
• Fundación General de la Universidad de Alcalá, together with Instituto Geográfico Nacional (FG-IGN), Spain
• Aalto University Metsähovi Radio Observatory (AALTO), Finland
• Commonwealth Scientific and Industrial Research Organisation (CSIRO), Australia

NREN Providers and Advanced Computing Facilities

• NORDUnet A/S (NORDUnet), Denmark
• SURFnet bv (SURFnet), The Netherlands
• Poznan Supercomputing and Networking Center (PSNC), Poland
• Delivery of Advanced Network Technology to Europe Limited (DANTE), EU (United Kingdom)
• Technische Universität München (TUM), Germany

www.nexpres.eu
nexpres@jive.nl
Tel: +31 (0)521 596 500
Fax: +31 (0)521 596 539

Mailing Address
Postbus 2
7990 AA Dwingeloo
The Netherlands

Visiting/Shipping Address
Oude Hoogeveensedijk 4
7991 PD Dwingeloo
The Netherlands

NEXPReS is an Integrated Infrastructure Initiative (I3), funded under the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement no. RI-261525, NEXPReS.