1. Google Sky

2. Worldwide R&D of Virtual Observatory
Chenzhou CUI
Chinese Virtual Observatory Project
National Astronomical Observatory of China

3. Content VO Introduction IVOA status, specifications and highlights
R&D activities from China-VO
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4. VO concept
Virtual Observatory (VO) is a data-intensively online astronomical research and education environment, taking advantages of advanced information technologies to achieve seamless, global access to astronomical information.
The power of the World Wide Web is its transparency. It is as if all the documents in the world are inside your PC. The idea of the Virtual Observatory is to achieve the same transparency for astronomical data and other related information (Quinn et al. 2004).
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5. IVOA in Growth International Virtual Observatory Alliance (IVOA)
formed in June 2002
with a mission to facilitate the international coordination and collaboration necessary for the development and deployment of the tools, systems and organizational structures necessary to enable the international utilization of astronomical archives as an integrated and interoperating virtual observatory.
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6. Science driven, technic enabled
VO drivers : science
multi-archive research
Precision Cosmology
The Time Domain
A Panchromatic approach to the Universe…
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7. Science driven, technic enabled
VO drivers : technology
hardware trends
ops, storage, bw : all 1000x/decade
data i/o bw 10x/decade
data avalanche
CCD array
digital sky survey
numerical simulation
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8. VO framework agreed standards inter-operable data collections
inter-operable software modules
no central VO-command
- its not a thing
- its a way of life
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9. What the Virtual Observatory is…
A suite of international standards for the discovery, exchange, intercomparison, and analysis of network-accessible astronomical data
A data access and analysis environment that exploits the emerging computation/software/data Grid
A framework for data processing that enables and encourages the re-use of algorithms
A tool for science planning: Identify gaps in coverage of parameter space. Which new missions, instruments, experiments will have largest impact?
A catalyst for world-wide access to astronomical archives
A routinely used tool of the research astronomer
A vehicle for education and public outreach
It is not a thing
VO is a way of life
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10. what is needed ? global standards well funded data centres
working data services
infrastructure software
VO aware client tools
VO aware data mining services
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11. IVOA Protocols key for interoperability

12. Protocol List VOTable FITS Cone Search Protocol
Simple Image Access (SIA) Protocol
Simple Spectral Access (SSA) Protocol
SkyNode
Astronomical Data Query Language (ADQL)
Uniform Column Descriptors (UCDs)
Space-Time Coordinates (STC)
IVOA Identifiers
VO Registry
Resource Metadata
Registry Access Protocols
OAI
VOEvent
NESSSI
VOSpace
PLASTIC
Common Execution Architecture
Request-Object Management Environment (ROME)
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13. Formats VOTable FITS XML format for tabular information
Catalog query results
List of images or spectra
Lists of resources
Includes UCDs for columns
FITS
Standard astronomical binary data format
Images, spectra, …
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14. Data Access Protocols Cone search Simple image access
Simple query around a given region
Returns VOTables
Simple image access
What images overlap a given region?
Create me an image of this region.
First step produces VOTables with links to image
User downloads images as FITS in second stage
Simple spectral access
What spectra are available within this region
More sophisticated than SIA (includes support for Data Models) but uses comparable framework
SkyNode
SOAP Web-Service based
Sophisticated access to tables
Supports distributed queries
Uses ADQL
Should eventually subsume Cone-search
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15. Query languages Astonomical Data Query Language (ADQL)
Enhanced version of SQL to support astronomical queries
Positional cross-correlations (XMATCH)
Complex regions on the sky (REGION)
Both SQL-like and XML representations
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16. Semantic content IVOA identifiers
Scheme for providing unique identifiers for any thing that needs to be distinguished. Services, requests, …
ivo://authority/authority_controlled_string#sub-resource
Used in registries and other protocols
Resource metadata
Standardized format for the description of a service, data collection, facility.
XML format based on the Dublin-core metadata descriptions for published resources.
Used inside registries.
Uniform Column/Content Descriptors (UCDs)
Standardized names for table columns with relatively high degree of specificity.
pos.eq.ra or phot.flux;em.ir
Used in VOTables and by Cone search and SIA
Space/Time Coordinates
Way of specifying points or regions of space-time.
Can be simple or very complex
Used in ADQL and VOEvent
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17. Discovering Resources
Registry
Collection of resources that users can find included Cone Search, SIA, SSA and SkyNodes.
User access via registry access protocol
Registry-registry communication via OAI
Some publishing registries are meant to be seen only by other registries
Registry access
How users query the registry
In standards process
Open Archive Interface (OAI)
Library community standard
Registry-registry communication to ensure that all registries are up to date.
VOEvent
VO protocol for publishing and receiving notice of transient/urgent events
Describes events using STC
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18. Accessing and Controlling Computer Resources
NESSI
NVO Extensible, Scalable, Secure Service Infrastructure
Provide access to protected resources, especially Grid computational resources.
Make it easy to do simple things.
First implementations just coming on-line
VOSpace
Access to storage resources in a standardized way.
PLASTIC
Platform for Astronomical Task InterCommunication
Applications publish and receive notifications of events from other applications (e.g., selection of a given object) to enable coordinated actions.
TOPCAT – Aladin
Deployed but still experimental.
Common Execution Environment (CEA)
Script/pipeline environment with security and such incorporated (Astrogrid)
ROME
Handle and schedule tasks that involve remote resources.
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19. Highlights from VO VO Infrastructures VO-oriented application
Miscellaneous tools
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20. CANS 2007, Aug , 2007, Xi'an
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21. Astrogrid Components Registry Community FileManager/Filestore
Workflow& Job Execution Service (JES)
Common Execution Architecture (CEA)
DataSet Access (DSA)
Workbench
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22. Aladin V4 – CDS (Euro-VO)
an interactive software sky atlas developed by CDS
MultiView, multiProjection
Resampling
Blinking: builds on the fly image sequences (slow movies)
GIF, JPEG and PNG support
Cut graph: along any segment
Cross match algorithm: for better object catalog analysis
Multi-language
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23. NVO Core Services
NVO Registry Portal: Find source catalogs, observation logs, image archives, and other astronomical resources registered with the NVO
DataScope:Discover and Explore Data in the Virtual Observatory
Open SkyQuery: Cross match yoru data with numerous catalogs
NVO Spectrum Services: Search, plot, and retrieve SDSS, 2dF, and other spectra
Web Source Extractor Upload images to SExtractor and cross-correlate the objects found with selected survey catalogs.
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24. CANS 2007, Aug , 2007, Xi'an
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25. VOPlot Tools from VO-India
A VO-I + CDS collaboration
VOPLot VOPLot3D VOMegaPLot
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26. History and current status
China-VO
History and current status

27. R&D Focuses China-VO Platform
中国虚拟天文台系统平台的开发
Unified Access to On-line Astronomical Resources and Services
国内外天文研究资源的统一访问
VO-ready Projects and Facilities
支持VO的项目与观测设施
VO-based Astronomical Research Activities
基于VO的天文研究示范
VO-based Public Education
基于VO的天文科普教育
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28. Two XSLT transforms VOFilter
an XML filter for OpenOffice.org Calc to open VOTable files
VOTable2XHTML
a stylesheet to transform VOTable data into HTML/XHTML format
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29. VO Data Access Service (VO-DAS)
An OGSA-DAI based service system to provide unified access to astronomy data, including catalogs, images and spectra.
Goals of VO-DAS
Supporting high volume data query
Interlinking distributed and heterogeneous archives
catalogs, images, spectrums
Providing a software that works for astronomers
OGSA-DAI Supported Asynchronous Data Access Service
OGSA-DAI is a middleware product which supports the exposure of data resources, such as relational or XML databases, on to grids.
Work with Globus Toolkit 4
WSRF interface
Good wrapper for variant databases
Asynchronous query supported
Available for large dataset
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30. Status An Alpha version of VO-DAS was ready Query Workflow
Synchronous Query
Asynchronous Query
Asynchronous Query on multiple DataNodes
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31. SkyMouse: Touch the sky with your mouse
Not like some VO efforts on unified access systems, for example, NVO DataScope, SkyMouse tries to show a comprehensive overview for a specific object, but not to snatch as much data as possible.
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32. VO Trends VO is inevitable, a new way of doing science
Present on every physical scale today, not just astronomy (NEON, Neptune, CERN, MS)
Driven by advances in technology, and economics, mapped onto society
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33. Q & A ?
www org
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