IVOA RM, VOResources, Identifiers, Interfaces

Chenzhou CUI

AgendaWhy Registry?IVOA Resource Metadata 1.01VOResource 0.10IVOA Identifiers 1.1IVOA Registry Interfaces 1.02

Semantic Web

Current WebResources:

identified by URI's untyped

Links: href, src, ... limited, non-descriptive

User: Exciting world - semantics of the resource, however, gleaned from content

Machine: Very little information available - significance of the links only evident from the context around the anchor.

Semantic WebResources:

Globally Identified by URI's or Locally scoped (Blank) Extensible Relational

Links: Identified by URI's Extensible Relational

User: Even more exciting world, richer user experience

Machine: More processable information is available (Data Web)

Computers and people: Work, learn and exchange knowledge effectively

Semantic Web一种能让计算机理解的新型 Web 内容形式 "The Semantic Web is an extension of the current web in which information is given well-defined meaning, better enabling computers and people to work in cooperation." -- Tim Berners-Lee, James Hendler, Ora Lassila, The Semantic Web, Scientific American, May 2001

MetadataMetadata: data for dataDublin Core Metadata

The role of Resource Registries

Used to discover and locate resources—data and services—that can be used in a VO application

Resource: anything that is describable and identifiable.Besides data and services: organizations, projects, software, …Presently concerned with simple set of resource types

Registry: a list of resource descriptionsExpressed as structured metadata

to enable automated processing and searching

An Overview of Data Discovery

You can search the main VO registries to find resources based on descriptive criteria

NVO Registries are “coarse-grained”You can find organizations, archives, catalogsWon’t find images, celestial objects, table records

AstroGrid Registries are “fine-grained”Table columns, individual images and associated metadata

Registry framework contains multiple registries:

searchable registriespublishing registries

Local PublishingRegistry Local

SearchableRegistry

FullSearchableRegistry

Local PublishingRegistry

FullSearchableRegistry

DataCenters

VOProjects

SpecializedPortals & Services

Registry Framework

Local PublishingRegistry Local

SearchableRegistry

FullSearchableRegistry

Local PublishingRegistry

FullSearchableRegistry

DataCenters

VOProjects

SpecializedPortals & Services

Registry Framework

harvest(pull)

Local PublishingRegistry Local

SearchableRegistry

FullSearchableRegistry

Local PublishingRegistry

FullSearchableRegistry

DataCenters

VOProjects

SpecializedPortals & Services

Registry Framework

harvest(pull)

replicate

Local PublishingRegistry Local

SearchableRegistry

FullSearchableRegistry

Local PublishingRegistry

FullSearchableRegistry

DataCenters

VOProjects

SpecializedPortals & Services

Registry Framework

harvest(pull)

replicate

selectiveharvesting

Local PublishingRegistry Local

SearchableRegistry

FullSearchableRegistry

Local PublishingRegistry

FullSearchableRegistry

DataCenters

VOProjects

SpecializedPortals & Services

ClientApplications

searchqueries

Registry Framework

Local PublishingRegistry Local

SearchableRegistry

FullSearchableRegistry

Local PublishingRegistry

FullSearchableRegistry

DataCenters

VOProjects

SpecializedPortals & Services

ClientApplications

searchqueries

Registry Framework

Persistent Archives:Tools for Federation

Registering your resources with a VO publishing registry

Enter description into registration form at one of the available NVO registries:

STScI/JHU Registry: http://nvo.stsci.edu/voregistry/NCSA Registration Portal: http://nvo.ncsa.uiuc.edu/nvoregistration.htmlCaltech Carnivore: http://mercury.cacr.caltech.edu:8080/carnivore/

If you have a large number of resources to register, you can run your own registry on your own site

NCSA VORegistry-in-a-Box http://nvo.ncsa.uiuc.edu/VO/software/Caltech Carnivore: http://mercury.cacr.caltech.edu:8080/carnivore/

IVOA Identifiers

Two formatsStringXML

Two componentsAuthority IDResource Key

Registry InterfacesSearch

SearchKeywordSearchGetResigistries

HarvestingIdentifyListIdentifiersListRecordsGetRecordsListMetadataFormatsListSets

The Registry standard addresses the need for an astronomer to be able to locate, get details of, and make use of, any resource located anywhere in the IVO space, ie in any Virtual Observatory.

IVOA Registry Definition: The IVOA Registry will allow an astronomer to be able to locate, get details of, and make use of, any resource located anywhere in the IVO space, ie in any Virtual Observatory. The IVOA will define the protocols and standards whereby different registry services are able to interoperate and thereby realise this goal.

IVOA Resource Registry Specifications

OAI linksOpen Archives Initiative Protocol for Metadata Harvesting (2.0)OAI - Repository Explorer(检测接口与OAI的兼容性）OAI Tools Registry Interface , HarvestingIssues