Hello!

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Hello!
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International Virtual Observatory Alliance
Ajit Kembhavi, IUCAA,
Pune
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Data Storage and Retrieval
The Astronomer Vermeer 1632-1675
The Library of Alexandria 3rd
Century BC
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Star Positions
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Stars in the Milky Way
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The Hertzsprung-Russell Diagram
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The Data Avalanche

• An increasing number of telescopes and large
  area detectors are producing immense amounts of
  data through imaging and spectroscopic surveys.
• Terabytes of data are now available, and
  Petabytes will soon be available from frequent
  all sky imaging.
• Vast databases are also being produced through
  simulations.

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Wavelength Coverage

• The data spans the electromagnetic spectrum from
  the radio to the gamma-ray region.
• Obtaining, analysing and interpreting the data in
  different wavebands involves highly specialised
  instruments and techniques.
• The astronomer needs new tools for using this
  wealth of data in multiwavelength studies.

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Virtual Observatories

• Manage vast data resources and provide these
  on-line to astronomers and other users.
• Provide tools for data analysis, visualization
  and mining.
• Develop interoperability concepts to make
  different databases seamless.
• Empower astronomers by providing sophisticated
  query and computational tools, and computing
  grids for producing new science.

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VO Schema
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Interactions
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The Alliance
Members of the IVOA
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IVOA Technology Initiatives

• The IVOA has identified six major
  technical initiatives to fulfill the scientific
  goal of the VO concept.

IVOA-LISTS
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• REGISTRIES These collect metadata about about
  data resources and information services into a
  queryable database. The registry is distributed.
  A variety of industry standards are being
  investigated.
• DATA MODELS This initiative aims to define the
  common elements of astronomical data structures
  and to provide a framework to describe their
  relationships.
• UNIFORM CONTENT DESCRIPTORS These will provide
  the common language for for metadata definitions
  for the VO.

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• DATA ACCESS LAYER This provides a standardized
  access mechanisms to distributed data objects.
  Initial prototypes are a Cone Search Protocol and
  a simple Image Access Protocol.
• VO QUERY LANGUAGE This will provide a standard
  query language which will go beyond the
  limitations of SQL.
• VOTable This is an XML mark-up standard or
  astronomical tables.

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VOTable

• This is a new data exchange standard produced
  through efforts led by Francois Ochsenbien of
  CDS, Strasbourg and Roy Williams of Caltech.
• VOTable is in XML format. Physical quantities
  come with sophisticated semantic information.

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VOTable

• The format enables computers to easily parse the
  information and communicate it to other
  computers.
• Federation and joining of information become
  possible and Grid computing is easier.
• VOTable parsers have been developed in Perl, Java
  and C.
• Enhancements and extensions are being considered.

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VOTable Data

• The data part in a VOTable may be represented
  using one of three different formats
• FITS VOTable can be used either to encapsulate
  FITS files, or to re-encode the metadata.
• BINARY Supported for efficiency and ease of
  programming, no FITS library is required, and the
  streaming paradigm is supported.
• TABLEDATA Pure XML format for small tables.

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Science Initiatives

• Many IVOA projects have active Science Working
  Groups consisting of astronomers from a broad
  cross-section of the community representing all
  wavelengths.
• The focus here is to develop a clear perception
  of the scientific requirements of a VO.
• Projects within the working groups will develop
  new capabilities for VO based analysis.
• This will enable the community to create new
  research programs and to publish their data and
  research in a more pervasive and scientifically
  useful manner.

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Caltech, Fermilab, JHU, NASA/HEARC, Microsoft,
NCSA/UIUC, NOAO, NRAO, Raytheon ITS, SDSC/UCSD,
SAO/CXC, STScI, UPenn, UPitts/CMU, UWis, USC,
USNO, USRA, CVO

• NVO-People

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Registry and DIS
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Terapix
Jodrell Bank
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AVO Prototype Demo Astrogrid Astronomy Catalogue
Extractor AVO AladinSED VO-IndiaVOPlot
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CVO Collaborations

• There are three major projects at the CVO
  involving collaborations with other VO.
• CVO is collaborating with the German
  Astrophysical VO to incorporate ROSAT X-ray data
  and catalogues into the CVO system.
• CVO is collaborating with the Australian VO.to
  incorporate 2Qz and 2DF galaxy spectra into the
  CVO database.
• CVO is an associate member of NVO and is have put
  in place some components of the NVO galaxy
  morphology demo.

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Australian VO Collaborations

• The distributed volume renderer (dvr) software,
  is a tool for rendering large volumetric data
  sets using the combined memory and processing
  resources of Beowulf like clusters.
• A collaboration between the Melbourne site of
  Aus-VO and AstroGrid aims to develop the existing
  dvr software into a grid-based volume rendering
  service.
• Users will be able to select FITS-format cubes
  from a number of "Data Centres",have the data
  transferred to a chosen rendering cluster, and
  then proceed to visualise the volume of data
  remotely (See Demo).

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Virtual Observatory - India
Persistent Systems
IUCAA
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VO-India Projects

• VOTable Parser in C Streaming data
• Web based FITS browser
• Visualizer for VIZIER
• Statistical packages for VIZIER and beyond
• GALics data bases
• Data mirror sites
• Scientific data mining
• Applications beyond astronomy

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The VOPLOT Collaboration
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The VOPlot Collaboration

• The idea for VOPlot was developed through a
  discussion between VO-I and CDS.
• VOPlot was developed by PSPL and IUCAA and was
  integrated into Vizier with the help of CDS.
• It was then decided to integrate VOPlot with
  Aladin, an interface was agreed on, and the
  integration is now complete.
• The collaboration was carried through a few short
  visits, phone calls and E-mail.
• Main persons Sonali Kale et al (PSPL), Pierre
  Fernique and Francois Ochsenbien. (CDS).

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