Free GIS Book: Metadata
Metadata Chapter - Sample Outline
OSGeo Metadata material and working groups
- The OSGeo Public Geospatial Data Project has formed a Geodata Discovery Working Group to work on specifying well-defined Geodata Metadata Requirements.
What is metadata?
A metadata record is a file of information, usually presented as an XML document, which captures the basic characteristics of a data or information resource. It represents the who, what, when, where, why and how of the resource. Geospatial metadata are used to document geographic digital resources such as Geographic Information System (GIS) files, geospatial databases, and earth imagery. A geospatial metadata record includes core library catalog elements such as Title, Abstract, and Publication Data; geographic elements such as Geographic Extent and Projection Information; and database elements such as Attribute Label Definitions and Attribute Domain Values (definitions courtesy the U.S. Geological Survey).
Why is metadata important?
Metadata helps people who use geospatial data find the data they need and determine how best to use it. Metadata supports producers in locating and using their own data resources and data consumers in locating and using data resources produced by others. Metadata also supports:
Data Management requirements to:
- preserve the data history so that it can be re-used or adapted,
- assess the age and character of data holdings to determine which data should be maintained, updated, or deleted,
- instill data accountability by requiring you to state what you know about the data and realizing what you don’t, but should, know about your data
- limit data liability by explicitly designating the effective and administrative limits of use of the data.
Project Management requirements to:
- plan and document the data types and content needed to support the project
- monitor data development by regular review of the process steps completed and recorded within the metadata
- provide all project participants a common language of attributes and process methods and a place to record and share their progress
- access the lineage and content of outsourced data production by requiring robust metadata as a contract deliverable.
As personnel change in an organization, institutional knowledge leaves the organization. Undocumented data can lose their value. Subsequent workers may have little understanding of the contents and uses for a digital data base and may find they can't trust results generated from these data. Also, lack of knowledge about other organizations' data can lead to duplication of effort. It may seem burdensome to add the cost of generating metadata to the cost of data collection, but in the long run metadata are worth it.
(courtesy the U.S. Geological Survey)
Here is a list of available metadata tools from the US Federal Geographic Data Committee.
Moritz Lennert wrote: Two examples of FOSS metadata tools:
- GeoNetwork (OSGeo project)
"GeoNetwork opensource implements both the Portal component and the Catalog database of a Spatial Data Infrastructure (SDI) defined in the OGC Reference Architecture. It provides tools for managing and publishing metadata on spatial data and related services."
"MDweb is a generic, multi-language, multi-standard, multi-platform tool for cataloging and locating environmental information, and, by extension, geographical data. [...] The specifications adopted for the cataloging of geographical information are based on the ISO 19115 standard and conform to Open Geospatial Consortium specifications and European directives (INSPIRE directives)."
Luca Casagrande commented:
"Don't know if this can help, but here: http://www.jornadasgvsig.gva.es/fileadmin/conselleria/Documentacion/3asJornadas/sesiones/sesion4/Gestion_metadatos_en_gvSIG.pdf
You can find the paper of "Semiautomatic extraction and management of metadata in gvSIG" presented during latest gvSIG conference."