Astro Working Group

1
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
• Map IVOA requirements onto Global Grid Forum
  standards
• Assess relevance of standards from each working
  group
• 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)
• Latency is important
• IVOA must deal with collections, catalog, image
  archives

2
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, non-discriminatory 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.

3
Infrasructure - NVO Summer School

• Web technology
• 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

4
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
• Virtual Observatory Metadata
• 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
  categoryinstancetype. Examples are
  phys.temperature for temperature,
  phot.fluxem.radioarith.ratio for a ratio of
  radio fluxes.
• STC Space-Time Coordinate descriptors

5
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
  one-dimensional 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

6
Virtual Observatory Services

• 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

7
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

8
Mapping of Services to Grid

• Utility
• 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
• Support for interactions with existing catalogs
  and image archives.
• Interoperability with Virtual Observatory
  community standards.
• Viability concerns
• Ease of implementation of the GGF standards
• Robustness of the standard.
• Scalability of the resulting service to support
  manipulation of 10-Terabyte collections and
  catalogs with 1 billion records.
• Timeliness.

9
Evaluation

• Paper examines each working group and makes a
  cursory attempt to evaluate
• Utility
• Meeting Virtual Observatory Requirements
• Viability
• At the moment, few of the standards efforts have
  viable technology
• We need input from GGF working groups to
  demonstrate why the Grid services will enable
  IVOA services

10
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
• 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
• Cone-Search catalog access
• OGSA DAIS / DFDL / GridFTP / OGSA naming / Grid
  Information Retrieval
• VOEvent event notification service
• Transaction management / Information Dissemination

11
IVOA Services

• VOStore access to image archives
• Grid Storage Management / GridFTP
• VOSpace management of shared data collections
• OGSA Naming / OGSA data replication / Grid File
  Systems /

12
GGF Services

• Infrastructure Standards Groups
• Ipv6
• Network Measurement
• Data Transport
• Grid High-Performance Networking
• Network Measurement for Applications
• Data Standards Groups
• 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
• Grid Resource Allocation Agreement Protocol

13
GGF Services

• Architecture Standards Groups
• Open Grid Services Architecture
• Grid Protocol Architecture
• OGSA Naming
• Applications Standards Groups
• Grid Remote Procedure Call
• Grid Information Retrieval
• Distributed Resource management Application API
• Simple API for Grid Applications
• Grid Checkpoint Recovery
• Management Standards Groups
• Application Contents Service
• Configuration Description, Deployment, and
  Lifecycle Management
• Grid Economic Services Architecture
• OGSA Resource Usage Service
• Usage Record
• Security Standards Groups
• Open Grid Service Architecture Authorization
• OGSA-P2P-Security