Astro Working Group
• Officers: Nic Walton (Astrogrid, Cambridge)
Guy Rixon (Astrogrid, Cambridge)
Secretary: Reagan Moore (SDSC)
• GGF paper in review on
 Building IVOA Services for the Astrophysics Community
• Examines how to
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Map IVOA requirements onto Global Grid Forum standards
Assess relevance of standards from each working group
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Needs to be updated
Written 22 September 2005
Seeking feedback from each working group
• Issues
 Many of the IVOA services are being implemented in advance of the GGF
standards
 IVOA must deal with small data (2 MB files) and large data (2 GB files)
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Latency is important
IVOA must deal with collections, catalog, image archives
www.gridforum.org
GGF-17 Astronomy Application Meeting
Intellectual Property Policy
• I acknowledge that participation in GGF8 is subject to the GGF Intellectual Property Policy.
• Intellectual Property Notices Note Well: All statements related to the activities of the GGF and
addressed to the GGF are subject to all provisions of Section 17 of GFD-C.1 (.pdf), which grants to
the GGF and its participants certain licenses and rights in such statements. Such statements include
verbal statements in GGF meetings, as well as written and electronic communications made at any
time or place, which are addressed to: the GGF plenary session,
• any GGF working group or portion thereof,
• the GFSG, or any member thereof on behalf of the GFSG,
• the GFAC, or any member thereof on behalf of the GFAC,
• any GGF mailing list, including any working group or research group list, or any other list functioning
under GGF auspices,
• the GFD Editor or the GWD process
• Statements made outside of a GGF meeting, mailing list or other function, that are clearly not
intended to be input to an GGF activity, group or function, are not subject to these provisions.
• Excerpt from Section 17 of GFD-C.1 Where the GFSG knows of rights, or claimed rights, the GGF
secretariat shall attempt to obtain from the claimant of such rights, a written assurance that upon
approval by the GFSG of the relevant GGF document(s), any party will be able to obtain the right to
implement, use and distribute the technology or works when implementing, using or distributing
technology based upon the specific specification(s) under openly specified, reasonable, nondiscriminatory terms. The working group or research group proposing the use of the technology with
respect to which the proprietary rights are claimed may assist the GGF secretariat in this effort. The
results of this procedure shall not affect advancement of document, except that the GFSG may defer
approval where a delay may facilitate the obtaining of such assurances. The results will, however, be
recorded by the GGF Secretariat, and made available. The GFSG may also direct that a summary of
the results be included in any GFD published containing the specification.
GGF Intellectual Property Policies are adapted from the IETF Intellectual Property Policies that
support the Internet Standards Process.
www.gridforum.org
GGF-17 Astronomy Application Meeting
Infrasructure - NVO Summer School
• Web technology
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Tomcat – webserver
SQL structured query language
XMLSchema / Xpath / Xquery / XML Stylesheet Language
WS-Security / SAML environment
SOAP messages
SOAP attachments / DIME, MTOM
WSDL services
WSRF statefull and asynchronous web services
 Languages
 Java
 C# programming language (Microsoft.Net and open source Mono version)
 IDL Interactive data language – libraries to support reduction, analysis, visualization of
astronomical data
 PHP scripting language and interface to MySQL database
 Python scripting language
 Data management
 MySQL – database
 Teragrid grid technology and data grid technology
www.gridforum.org
GGF-17 Astronomy Application Meeting
Data and Metadata Standards
• Data Encodings
VOTable – XML standard for the interchange of data represented as a set of
tables. The standard separates data and metadata, and uses XML tags to
allow validation and transformation of an input document.
 FITS – Image encoding standard
 ADQL – Astronomy Data Query Language extensions to SQL for spatial
queries
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• Virtual Observatory Metadata
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VOResource description standard for registering catalogs. Components
include the access URL for the information contained in the resource.
 UCD – IVOA controlled formal vocabulary for astronomical data. Uniform
Content Descriptors are built by combining words from the controlled
vocabulary to define the type of physical quantities. The syntax specifies
the general category and specific instance as “category;instance;type”.
Examples are “phys.temperature” for temperature,
“phot.flux;em.radio;arith.ratio’ for a ratio of radio fluxes.
 STC – Space-Time Coordinate descriptors
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GGF-17 Astronomy Application Meeting
Virtual Observatory Access Mechanisms
• SIAP - Simple Image Access protocol returning pointers
to the requested information encapsulated in a VOTable
format.
• SSAP - Simple Spectral Access Protocol for onedimensional spectra, time series, and Spectral Energy
Distributions. Returns pointers to the information
encapsulated in a VOTable format.
• Cone-Search – catalog access
• VOEvent – event notification service
• VOStore – access to image archives
• VOSpace – management of shared data collections
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GGF-17 Astronomy Application Meeting
Virtual Observatory Services
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Montage – dynamic creation of mosaics of images
Mirage
Topcat
VOPlot - visualization
Downloadmanager script to support queries on Cone/SIAP services
and file download
ReadVotable java program to list the rist line of a VOTable and all its
fields
Mosaic – creation of mosaics of images retrieved from image
archives
Voogle – Virtual Observatory interface
WESIX – extract source catalogs from stacked Sloan Digital Sky
Survey images
Object classifiers
Outlier-detection
FITS header validation
www.gridforum.org
GGF-17 Astronomy Application Meeting
Portals
• OpenSkyQuery – correlation service for cross matching
records from major catalogs in small areas of the sky.
Parameters are selected using criteria based on
comparisons between values.
• SkyNode – standard interface to existing catalogs
• Virtual Observatory Registry – OAI-PMH compliant
registry of available Skynodes
• SkyPortal – interface for composing ADQL queries
• IRAF Image Reduction and Analysis Facility – general
purpose software system for the reduction and analysis
of optical/infra-red astronomical data. Commands
include task invocation, parameter specification,
graphics/image display, interactive and batch execution,
command language scripting
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GGF-17 Astronomy Application Meeting
Mapping of Services to Grid
• Utility
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How the proposed GGF standard might be used to implement a
Virtual Observatory Protocol.
 What advantages the GGF standard would provide over the current
implementation.
• Virtual Observatory requirements
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Support for interactions with existing catalogs and image archives.
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Interoperability with Virtual Observatory community standards.
• Viability concerns:
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Ease of implementation of the GGF standards
 Robustness of the standard.
 Scalability of the resulting service to support manipulation of 10Terabyte collections and catalogs with 1 billion records.
 Timeliness.
www.gridforum.org
GGF-17 Astronomy Application Meeting
Evaluation
• Paper examines each working group and makes a
cursory attempt to evaluate
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Utility
 Meeting Virtual Observatory Requirements
 Viability
• At the moment, few of the standards efforts have viable
technology
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We need input from GGF working groups to demonstrate why the
Grid services will enable IVOA services
www.gridforum.org
GGF-17 Astronomy Application Meeting
IVOA Services
 Virtual Observatory Protocols
 SIAP - Simple Image Access protocol returning pointers to the
requested information encapsulated in a VOTable format.
• Requires extraction of a subset of an image from a remote collection
• SAGA / Grid File System / DFDL / GridFTP / Byte IO / OGSA naming
• Grid Remote Procedure Call
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SSAP - Simple Spectral Access Protocol for one-dimensional spectra,
time series, and Spectral Energy Distributions. Returns pointers to the
information encapsulated in a VOTable format.
• OGSA DAIS / DFDL / GridFTP / OGSA naming
• Grid Remote Procedure Call
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Cone-Search – catalog access
• OGSA DAIS / DFDL / GridFTP / OGSA naming / Grid Information Retrieval
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VOEvent – event notification service
• Transaction management / Information Dissemination
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GGF-17 Astronomy Application Meeting
IVOA Services
 VOStore
– access to image archives
• Grid Storage Management / GridFTP
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VOSpace – management of shared data collections
• OGSA Naming / OGSA data replication / Grid File Systems /
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GGF-17 Astronomy Application Meeting
GGF Services
• Infrastructure Standards Groups
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Ipv6
Network Measurement
Data Transport
Grid High-Performance Networking
Network Measurement for Applications
• Data Standards Groups
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Data Access and Integration Services
Grid File Systems
Data Format Description Language
GridFTP
Grid Storage Management
Information Dissemination
OGSA Data Replication Services
Transaction Management
OGSA Data
Byte IO
• 3Compute Standards Groups
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Grid Resource Allocation Agreement Protocol
Job Submission Description Language
Grid Scheduling Architecture
OGSA Basic Execution Services
www.gridforum.org
GGF-17 Astronomy Application Meeting
GGF Services
• Architecture Standards Groups
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Open Grid Services Architecture
 Grid Protocol Architecture
 OGSA Naming
• Applications Standards Groups
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Grid Remote Procedure Call
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Grid Information Retrieval
Distributed Resource management Application API
Simple API for Grid Applications
Grid Checkpoint Recovery
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• Management Standards Groups
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Application Contents Service
 Configuration Description, Deployment, and Lifecycle Management
 Grid Economic Services Architecture
 OGSA Resource Usage Service
 Usage Record
• Security Standards Groups
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Open Grid Service Architecture Authorization
 OGSA-P2P-Security
 Firewall Issues
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Trusted Computing
www.gridforum.org
GGF-17 Astronomy Application Meeting