Data Standards - Metadata
is data about the data. It consists of information that describes
spatial data and is used to provide documentation for data products.
For example, metadata describes the format, geographic boundary,
projection, coordinate system, availability and cost, etc., of a
spatial data set (i.e. road network data, political boundary data,
and satellite imagery). Metadata is the who, what, when, where,
why, and how of spatial data.
Geological Survey Metadata FAQ (Frequently Asked Questions)
Why use or create metadata?
There are three major advantages for using or creating metadata:
1) To help organize
and maintain an organization's spatial data.
Metadata will allow an organization
to keep track of what data products they own or are creating. Employees
may come and go but metadata can catalogue the changes and updates
made to each spatial data set and how each employee implemented
2) To provide information
to other organizations and clearinghouses to facilitate data sharing
It makes sense to share existing
data sets rather than producing new ones if they are already available.
Metadata facilitates this process by documenting what each data
set consists of. Metadata tells a prospective buyer exactly what
he is getting before purchasing a data set.
3) To document the
history of a spatial data set.
Spatial data sets rarely stay
in their original format. Metadata documents what changes have been
made to each data set, such as changes in geographic projection,
adding or deleting attributes, editing line intersections, or changing
file formats. All of these could have an effect on data quality.
Remember, the key purpose of
metadata is to facilitate and improve the retrieval and sharing
There are different national and
international metadata standards currently being implemented. The
United Stated Federal Geographic Data Commission (FGDC)
has adopted the Content
Standard for Digital Geospatial Metadata (CSDGM), Australia
has a standard implemented by the Australia
New Zealand Land Information Council (ANZLIC), and the European
Union (EU) is working to implement an European
Geographic Information Infrastructure (EGII). Currently, the
Organization for Standardization (ISO) is developing a geospatial
metadata standard. (ISO
A geospatial clearinghouse provides
access to digital spatial data by searching metadata.
A clearinghouse site indexes all
of its metadata which will enable a user to search for spatial data
by submitting a query. If a match is found, all relevant metadata
will be displayed to the user. Clearinghouse sites are encouraged
to provide hypertext linkages within their metadata entries that
enable users to directly download the digital data set in one or
more formats or give instruction on how to obtain the data.
Geospatial Metadata Clearinghouses
Geospatial Data Clearinghouse
Valley National Geospatial Data Clearinghouse - (This site is currently down)
Land Information Clearinghouse (WISCLINC)
4: Geospatial Metadata
Metadata Collector v. 2.0
The ArcView® Metadata Collector v 2.0 is an easy to use
software application which can be utilized by any ArcView
3.x user without having to fully understand the Federal
Geographic Data Committee's (FGDC) "Content Standards
for Digital Geospatial Metadata." The tool provides
a dialogue for creating FGDC compliant metadata for most
data types supported by ArcView. The tool automatically
extracts information (metadata) such as bounding coordinates,
spatial data organization information and attribute information.
In addition, the tool allows users to store information
as .dbf and text (.txt) files that can be edited, if needed,
and reused for subsequent metadata records. The application
generates output in both text and HTML formats. If you are
creating metadata for an ARC/INFO® coverage, you also have
the option of generating an INFO file that will become part
of that coverage.
(Chew and Spit)
cns (chew and spit) is a pre-parser for
formal metadata designed to assist metadata managers convert
records that cannot be parsed by mp
into records that can be parsed by mp. It takes as input
a poorly-formatted metadata file and, optionally, a list
of element aliases, and outputs (1) a metadata file that
can be read by both mp and xtme and (2) a file listing all
of the lines that it could not figure out where to put.
This is especially useful for clearinghouses which may
collect metadata from source agencies producing metadata
differing in format because of the metadata tool or template
employed at each agency, or because the agency metadata
profile differs from the CSDGM.
Corpsmet95 is a CSDGM tool developed for the U.S. Army
Corps of Engineers by Coastal Oceanographics, Incorporated.
It is a version of, or probably identical to, the commercial
FGDCMETA.AML is an extremely simplified variant of DOCUMENT.AML
that generates metadata files in ASCII text from Arc/Info
geo_datasets in a UNIX or NT environment. File structure
and content conform with the FGDC Content Standard for Digital
Geospatial Metadata. The output template is intended to
be customized to the individual user's needs (which requires
rudimentary knowledge of AML). Resulting files are intended
for use with other metadata tools that conform to the FGDC
metadata standard (such as xtme, tkme and mp).
This program is a compiler to parse formal metadata, checking
the syntax against the FGDC
Content Standard for Digital Geospatial Metadata and
generating output suitable for viewing with a web browser
or text editor. It runs on UNIX systems and on PC's running
Windows 95, 98, or NT. MP generates a textual report indicating
errors in the metadata, primarily in the structure but also
in the values of some of the scalar elements (i.e. those
whose values are restricted by the standard).
The editor shares a considerable amount of its code with
its companion product, Xtme,
which is specifically for Unix systems and is based on the
Athena widget set of the standard X Window System distribution.
Both Tkme and Xtme are closely allied with mp,
compiler for formal metadata, whose purpose is to verify
that the syntactical structure of a file containing formal
metadata conforms to the FGDC standard, and to reexpress
the metadata in various useful formats. The editors are
intended to simplify the process of creating metadata that
conform to the standard.
Xed is a programmer's text editor for use on UNIX computers
with the X Window System, Macintosh computers, and 80386-based
MS-DOS computers. It is designed to be small, fast, simple
to use, and easy to customize.