About geospatial metadata and dataset description

Geospatial metadata (data about data) consistently describes datasets (collections of spatial data). This enables effective management and availability of that data. Each online dataset description forms an interface to the actual data and to more information about it.

See also: IndexGeo / Geospatial metadata / About metadata

What is metadata

Metadata is data about data. A dataset description is a metadata document, describing the data, but is not the actual data itself.

The dataset description document is well-defined and structured using elements of metadata. It is analogous to a card in the catalogue of your local library which describes the books and gives enough information to know what the book is called, its unique number, how and where to find it. These details are metadata - bibliographic elements such as Author, Title, Abstract.

About geospatial dataset descriptions

Geospatial dataset descriptions describe spatial data, data that has reference to a location in earth-centred space.

Geospatial dataset descriptions are composed of well-defined metadata elements which have a specific structure and order. The dataset descriptions are maintained as documents in the Standard Generalised Markup Language (SGML).

Importantly, the document must conform to the Document Type Definition (DTD) which defines the allowed elements and their order and structure. The DTD is "used to automatically process a document ... and check that all of the elements required for that document are indeed present and correctly ordered" [from A Gentle Introduction to SGML].

The ANZMETA DTD defines geospatial datasets in Australia and New Zealand.

Reasons and incentives for metadata

Geospatial metadata has many uses, including:

• concisely describe datasets and other resources
  • using elements such as: the name of the dataset, the quality, who is the custodian, how to access the data, what is its intended purpose, who to contact for more information about the data
• enable effective management of resources
• provide an online interface to a dataset and link to other information about it
• serve as a record in a searchable catalogue of datasets
  • search software will index each dataset description document, using the words in each metadata element, to create a database that can be searched using keywords
• accompany a dataset when it is transferred to another computer, so that the dataset can be fully understood and put to proper use and so that custodians are duly acknowledged
• when datasets are properly documented, then these resources are less likely to be duplicated
• corporate knowledge and investment is preserved, employees may come and go but their knowledge has been documented

More information

• The Australia New Zealand Land Information Council (ANZLIC) has more information about the Australian Spatial Data Directory.
• ANZLIC Metadata Working Group
• The Australian and New Zealand spatial data community talks about geospatial metadata on the OZMETA-L email discussion list. Search OZMETA-L.
• The ANZMETA XML DTD and supporting documentation can be found at http://www.environment.gov.au/database/metadata/anzmeta/
• Core Metadata Elements for Land and Geographic Directories in Australia and New Zealand - ANZLIC Guidelines
• See MetaWeb - the "Metadata Tools and Services Project" at DSTC.
• See W3C Metadata and Resource Description

• Our glossary explains the terms used here
• Search the Geospatial acronyms server and read about it
• IndexGeo home page
• Eco Companion Australasia - environmental resources catalogue
  • provides members with online dataset management facilities

URL:http://www.indexgeo.com.au/metadata/metadata.html
Last Modified: 26 May 2000