Resource Metadata

Last updated: 19 May 2010 - RayPlante

Standard Specifications

The standards for metadata used to describe resources in the VO come in two forms: prose documents that define the metadata concepts and XML Schemas used to encode them.

Metadata Definition Documents

Resource Metadata (RM)

IVOA Recommendation

"Resource Metadata for the Virtual Observatory" v1.01
Robert Hanisch, Ed.

This document (euphemistically referred to as "RM") defines standard metadata concepts that describe resources, independent of any particular encoding format. It also describe the general resource model upon which the concepts are based.

This document is intended primarily for developers of new standards for encoding resource metadata.

IVOA Working Draft

"Astronomy Visualization Metadata (AVM)" v1.1
Adrienne Gauthier, Editor.

This document defines a set of metadata that can be used to describe graphical images (e.g. JPEG, GIF, etc.) used for astronomy public outreach. It was developed via the IAU Virtual Astronomy Multimedia Project (VAMP) with input from the broader astronomical outreach community. The AstroVisualiztionMetadata page covers discussion of this document as a candidate IVOA standard.

XML Schemas

VOResource

IVOA Recommendation

VOResource: an XML Encoding Schema for Resource Metadata (v1.03)
RayPlante, Editor. RFC completed Aug 2007.

VOResource in general refers to a set of XML Schemas that includes a core schema (VOResource-vX.X.xsd) based on the RM Recommendation and a set of standard extension schemas that define particular types of resources.

These schemas are intended for use by VO XML-based applications. In particular, these schemas are used for supporting interoperable communication with resource registries.

VODataService

Recommendation

VODataService: a VOResource extension for Data Collections and Services, v1.1 (Aurelien Stebe and Ray Plante, editors)

• discussion, examples
• Request For Comment (RFC) -- in progress

StandardsRegExt (VOStandard)

Formerly known as VOStandard, StandardsRegExt defines the extension schema for describing standards (along with concepts in those standards) so that they can be referred to via an IVOA identifier.

Recommendation

StandardsRegExt: a VOResource Schema Extension for Describing IVOA Standards

Simple Services (SCS, SIA, SSA, SLA)

Formerly known as RegSimpleDAL, SimpleDALRegExt defines extension schemas for describing SIA (schema), SSA (schema), SLA (schema), and ConeSearch (schema). This document is under TCG review (see SimpleDALRegExt10RFC).

ApplicationsRegExt (VOApplication)

ApplicationsRegExt (formerly VOApplication) is a registry extension schema that allows one to register applications, tools, and libraries. A working draft of a document defining the extension schemas for describing applications is under development at RegDMApplications.

At the Fall 2009 Interop, the Registry Working Group agreed to table the development of this schema until a stronger driver emerges. Contributions and comments are still welcome; we are particularly interested in use cases that need the ability to dynamically discover applications. Discussion was revived again the spring and fall of 2011, and a similar conclusion was reached

Other Extensions in Development

Additional extensions are expected to be driven by other Working Groups as part of the development of new protocols. At the moment, extensions are in development for the following protocols:

• Table Access Protocol (TAP) (DAL)
• Simple Event Access Protocol (SEAP) (VOEvent)
• Spectral Line Access Protocol (SLAP) (DAL)

For information about how to create a new registry extension, see the next section.

Creating Registry Extensions

The VOResource has been designed to allow new metadata to be defined as an extension on the core. The VOResource specification recommends how to create extension schemas. Additional information about extending the VOResource schema can be found on the VOResource page.

Useful Links and Tools for Developers

• Tools for converting VOResource v0.10 to v1.0 can be found at RegUpgradeToV10

Deprecated versions

• VOResource v0.10
• VOResource v0.9
• Stylesheets for converting VOResource documents between versions 0.9 and 0.10:
  • VOResource-v0.9-v0.10.xsl
  • VOResource-v0.10-v0.9.xsl
• vor2dc_v9.xsl: XSL Stylesheet to convert VOResource v0.9 to OAI Dublin Core.
• vomdoc-v0.3.xsl: XSL Stylesheet for creating HTML documentation for VOResource v0.9 and its extensions.
• Schema to XForms converter (for VOResource v0.10): xsd2XFm.xsl. See this summary for details.