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The astronomical Virtual Observatory

The astronomical Virtual Observatory. Sharing astronomical data : why. Major scientific objectives Long term observations of variable natural phenomena A large number of objects, complex interactions, many scales

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The astronomical Virtual Observatory

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  1. Theastronomical Virtual Observatory ICSTI Workshop, 2012/03/05, F. Genova

  2. Sharing astronomical data : why • Major scientific objectives • Long term observations of variable natural phenomena • A large number of objects, complex interactions, many scales • Observations with different techniques, at different scales (ground- and space-based observatories, large surveys) Multi-wavelength observations make a significant and increasing fraction of publications • Re-using data for scientific objectives different from the original ones, i.e. optimize the science return of large ground- and space-based instruments and of large surveys IUE (1978-1996): five times more publications from data retrieved in the archive than from the selected observing teams (Wamsteker, Griffin, 1995) – a major precursor ICSTI Workshop, 2012/03/05, F. Genova

  3. Astronomy data landscape • On-line information and services: heterogeneous, distributed observatory archives, value-added services and tools (CDS), electronicjournals and the NASA ADS bibliographicdatabase, modelling data, tools, etc • Lots of workbehind the scene: re-using data requiresthat • itisproperlydescribed • users trust its QUALITY • On-line services are widelyused by the astronomicalcommunity ICSTI Workshop, 2012/03/05, F. Genova

  4. Data policy • Based on data sharing • Observational data obtainedthroughcompetitiveprocess, available to all in observatory archives (after a 1 yearproprietaryperiod) • Academicjournals • A smallnumber of major journalsoftenmanaged by AstronomicalSocieties or international agreement (Astronomy & Astrophysics, 25 member countries from Europe and South America) • Table of contents and abstracts freelyavailable, as wellis ‘long’ tables at CDS (« attached data ») • Open accessafter 1-3 years, immediate open access to a significant part of A&A • Wide use of arXiv e-print archive ICSTI Workshop, 2012/03/05, F. Genova

  5. The VO: We did not start from nothingA network of on-line services • The community is used to define exchange standards in international partnership • More than 30 years ago: FITS (observational data) • Since 1983: bibcode (1999A&A…447…89T) • Even before the Web: remote query to services • Since 1993, implementation and networking of on-line services covering the whole range of ‘data’ – in particular for bibliographic information ICSTI Workshop, 2012/03/05, F. Genova

  6. A unified access to tables published in journals (CDS & journals) • Common description • Improvedquality: Checkscomplementary to the referee’s • Data discovery: VO-enabled content description • Data retrieval • Also more general ‘additional data ’ http://vizier.u-strasbg.fr/viz-bin/vizHelp?cats/cats.htx ICSTI Workshop, 2012/03/05, F. Genova

  7. The astronomical Virtual Observatory • Enable seamless access to the wealth of on-line astronomy resources all the world’s astronomical data should feel like they sit on the astronomer’s desktop workspace An ambitious goal and no pre-existing organisational model to follow (~2000) • Pragmatic approach with a few basic principles • A global VO • Always keep in mind science usage and implementation by data centres • Fulfil astronomy’s needs (disciplinary VRE) BUT when possible use generic building blocks to allow wider interoperability • Global interoperability requires international agreement The definition of interoperability standards is overseen by the International Virtual Observatory Alliance ICSTI Workshop, 2012/03/05, F. Genova

  8. The IVOA • Precursor: a Work Package of the European OPTICON network led by CDS (international already) • IVOA created in 2002 • Alliance of VO projects • Procedure adapted from W3C (WD, PR, REC) • Working Groups and interest groups on the different aspects • Now in implementation phase but maintenance and new topics require sustainability • Any data centre can join by implementing the interoperability layer http://www.ivoa.net/Documents/ ICSTI Workshop, 2012/03/05, F. Genova

  9. VO architecture http://www.ivoa.net/Documents/Notes/IVOAArchitecture/index.html ICSTI Workshop, 2012/03/05, F. Genova

  10. Continuing to work on standards remainsmandatory Feedback fromimplementation and scientific usage Evolution of astronomy – new facilities, new science Evolution of technology Interoperability: current status Passage to maintenance mode for many standards From C. Arviset VO-enabledaccess to VizieR (in blue)

  11. VO evolution • The VO has never been solely a technologydevelopment • Scientists and data providers have been participatingfrom the beginning in the VO development • Thingshad to be made in the properorder • The basic building blocks (standards and tools) had to be – and have been – built, with in mindtake-up by data centres and science users • Nowtowardsoperational phase • The focus ismovingtowards more support to take-up by scientists and data providers, plus outreachtowardseducation

  12. Science requirements • Science requirements have been presentfrom the beginning • Scientists in VO projects • Science AdvisoryCommittees of individualprojects • Science demos • When the basic standards have been developed, IVOA set up a Committee, then a Standing Committee for Science Priorities to identifyhighpriority science cases, thenperforms a gap analysis to identify the lacking standards ICSTI Workshop, 2012/03/05, F. Genova

  13. Impact on Data Providers:The Euro-VO census • Census of European Data Centres (EuroVO-DCA, EuroVO-AIDA, 2009, 2010) • Inclusive definition : Data Centres populate the VO with data and services, service to the community, added-value, sustainability, quality • 69 ‘data centres’ answered Data archives, services, theory data and services

  14. Data centres in Europe (and elsewhere!) • A hugediversity in aims • large archives of ground- and space-basedtelescopesprovidedby national or international agencies • large systematicsurveys of the sky, results of large simulations • generalist data bases and services • smaller contributions of scientific teams whichsharetheirexpertise • Hugediversity in size and organisations • An ecosystem of data and service providers willing to share data and knowledge - a distributed, heterogeneous system with no a central point norhierarchical organisation

  15. Strands of work during operational phase • Support to take-up by data providers • Support to take-up by the scientificcommunity • Continuoustechnicaldevelopment • Standards (update of existing standards and new standards because of feedback/evolutions) – VO teams + IVOA • Tools • Outreachtowardseducation and the general public • Interdisciplinarity a must in the current « political » context

  16. Interdisciplinary aspects • IVOA had in mind to use generic components when possible. e.g. for twocritical components for « wide » interoperability • Registry of Resources: OAI-PMH, Dublin Core (with extensions) • Vocabulary: RDF + SKOS (semantic web) • Re-use/adaptation by other disciplines: pragmaticapproachthroughdissemination of knowledge by knowledgeable staff in EU projects in « nearby » disciplines (HELIO et al., VAMDC)

  17. The astronomy knowledge infrastructure • Science driven information network widely used by the scientific community • A model based on open access to data and services (pragmatic open access strategy) • A fully distributed model • Agencies responsible for large infrastructures provide data archives • Established data centres provide value-added services and tools • Now smaller, motivated actors are appearing – labs willing to share their knowledge • Links, portals, access tools • Mid-term sustainability • Support to archive/data centres • Support to national projects which work on interoperability and tools • Support to the International (and European) layers ICSTI Workshop, 2012/03/05, F. Genova

  18. Europeanstrategies European strategic exercise for astronomy: Astronet Roadmap (2008) The data/service infrastructure is an important part of the disciplinary infrastructure Riding the Wave report of the EU High Level Expert Group on Scientific Data Data is an infrastructure Collaborative Data Infrastructure ICSTI Workshop, 2012/03/05, F. Genova

  19. Conclusion • Astronomy : a global, heterogeneous, distributed, open data infrastructure widely used by the scientific community • Multipolar, with no central point • Open to large organisations as well as to labs willing to share their knowledge • The sharing of knowledge is a global challenge • No single model – the way disciplines organize themselves to share their data is strongly dependent on their culture • Any Collaborative Data Infrastructure should be able to accommodate disciplinary « pillars » when they exist ICSTI Workshop, 2012/03/05, F. Genova

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