Metadata
Lecture 7
October 5, 2006
Value of Documents

Two very similar paintings of circus performers by
Picasso from 1904 are put on the auction block; one
brings tens of millions of dollars, the other hundreds
of thousands. What is the difference? In one case,
the ownership of the painting can be traced through
sales slips and auction house records back to the
estate of Picasso's dealer. The other painting
appeared suddenly on the art market. They both
appear to be original Picasso's but one lacks
documentation. How can one be sure the
undocumented painting is authentic?
Examples of non-spatial metadata
What is metadata



Meta is defined as a change or transformation. Data is
described as the factual information used as a basis for
reasoning. Put these two definitions together and
metadata would literally mean "factual information used as
a basis for reasoning which describes a change or
transformation."
In GIS, Metadata is data about the data. It consists of
information that describes spatial data and is used to
provide documentation for data products. Metadata is the
who, what, when, where, why, and how about every
facet of the spatial data.
According to the Federal Geographic Data Committee
(FGDC), metadata is data about the content, quality,
condition, and other characteristics of data.
Metadata:
A part of Geographic Data

Metadata is the third
component of
geographic data.
Geospatial data tells
you where it is and
attribute data tells
you what it is.
Metadata describes
both geospatial and
attribute data.
Why use and create metadata



To help organize and maintain an organization's spatial
data
- Employees may come and go but metadata can
catalogue the changes and updates made to each spatial
data set and how each employee implemented them
To provide information to other organizations and
clearinghouses to facilitate data sharing and transfer
- It makes sense to share existing data sets rather
than producing new ones if they are already available
To document the history of a spatial data set
- 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.
Metadata Should Include Data
about













Date of data collected.
Date of coverage generated.
Bounding coordinates.
Processing steps.

Software used

RMSE, etc.
From where original data came.
Who did processing.
Projection
coordinate System
Datum
Units
Spatial scale
Attribute definitions
Who to contact for more information
See an example of non-standard metadata (see)
Federal Geographic Data Committee’s
(FGDC) Content Standard for Digital
Geospatial Metadata (CSDGM)


The FGDC is developing the National Spatial Data
Infrastructure (NSDI) in cooperation with organizations
from State, local and tribal governments, the academic
community, and the private sector. The NSDI
encompasses policies, standards, and procedures for
organizations to cooperatively produce and
share geographic data.
The objectives of the CSDGM are to provide a common
set of terminology and definitions for the documentation
of digital geospatial data.
CSDGM (FGDC-STD-001-1998)

Metadata =







Identification_Information
Data_Quality_Information
Spatial_Data_Organization_Information
Spatial_Reference_Information
Entity_and_Attribute_Information
Distribution_Information
Metadata_Reference_Information
Connect to http://www.fgdc.gov/metadata/csdgm/
Metadata tools

Metadata editors:
-

tkme / USGS
ArcCatalog / ESRI
SMMS / Intergraph
FGDCMETA / Illinois State Geological Survey
xtme / USGS
Metadata utilities (check compliance and export to text,
HTML,XML, or SGML):
- mp / USGS
- MP batch / Intergraph
- ArcCatalog powered by mp/ ESRI

mp: Metadata Parser
Metadata Server
- Isite / FGDC
- GeoConnect Geodata Management Server / Intergraph
- ArcIMS Metadata Server / ESRI
FGDC Clearinghouse


the FGDC developed a clearinghouse
that allows geospatial data creators to
share their data
however, the FGDC Clearinghouse is not
a data repository. The data contained
within the clearinghouse is actually
stored on computer servers maintained
by individual contributors. This allows
contributors to manage their own data.
Two Components




The FGDC Clearinghouse consists of 6
gateways and 250 nodes
A gateway is a point of entry into the
FGDC Clearinghouse
A clearinghouse node is a database
that contains metadata records.
Individual contributors maintain nodes
Besides the FGDC Clearinghouse,
there are a variety of other
communities that use FGDC-compliant
metadata as the basis of their data
sharing services. These so-called
clearinghouse communities are often
developed because the participating
organizations have data of similar or
complementary types.
http://clearinghouse1.fgdc.gov/
Example of Using the FGDC
Clearinghouse

Your company is bidding on a spatial analysis
project in the Chicago area. Your role on the
proposal team is to find available data for the
different components of the GIS you would be
required to build. Of utmost importance is
transportation data, and there is no way that
your company will win the bid if they have to go
out and collect new data. The data needs to be
at least as current as 1995. Being a resourceful
employee, you decide to explore the FGDC
Clearinghouse to see what data is available.
http://clearinghouse1.fgdc.gov/
http://www.fgdc.gov/
Source: www.esri.com