.. _metadata:
Metadata Background
===================
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Metadata is often described as "data about data", or the *who*, *what*, *where*,
and *when*. In the spatial world, for each dataset we maintain, we should record
information about the data such as:
- general description
- location
- usage restrictions
- projection
- technical contact
- date created
- date modified
- version
Benefits
--------
Maintaining metadata for your datasets is important for several reasons:
1. Internal: local management
- tracking dataset management
- scheduling data updates
2. External: discovery
- allowing your dataset to be used outside your organization
Standardized Metadata
---------------------
With the growth of geographic information systems (GIS) in the 1980's and 1990's, geographic
datasets became a requirement for decision makers across the world. The expansion of
the Internet to share information through the late 1990's and 2000's has now brought
'discovery' of geographic data into the hands of the average citizen.
.. note::
Metadata standards have been introduced since the mid 1990's with the goals of:
- outlining specific required parameters
- common terminology
- consistency
- interoperability
Dublin Core
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:target: http://dublincore.org/
- named from workshop in Dublin, Ohio in 1995
- established a core/common group of 15 metadata elements
Example:
.. code-block:: xml
..
FGDC Content Standard for Digital Geospatial Metadata (CSDGM)
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- approved by the U.S. Federal Geographic Data Committee originally in 1994
- composed of Sections, Compound Elements, Data Elements
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:target: http://www.fgdc.gov/csdgmgraphical/index.html
ISO 19115
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- International Standards Organization's TC211 committee created this in 2003
- consisting of more than 400 "Core", "Mandatory", and "Optional" elements
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ISO 19139
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- the XML implementation schema for ISO 19115 specifying the metadata record format
- may be used to describe, validate, and exchange geospatial metadata prepared in XML