by
Chris Pfeiffer
Metadata, or in this case Geospatial Metadata, documents descriptive
and practical information about a particular dataset, database or geographic
information system coverage. Metadata on PASDA conforms to the Federal
Geospatial Data Committee's (FGDC) Content Standard for Geospatial Metadata.
The Content Standard was derived as a part of the FGDC's reation of
the National Spatial Data Infrastructure (NSDI) to promote the sharing
of geospatial data throughout federal, state and local governments and
through their constituencies and compliant metadata allows for the inclusion
in the FGDC's national clearinghouse for GIS data. PASDA contains metadata
for all of the data available for download through the site as well
as data made available by organizations and government agencies from
throughout the state of Pennsylvania. This provides a clearinghouse
through which any potential data user can determine if certain data
is available and how to go about acquiring that data. The metadata standard
outlines a formal and structured document that contains information
that identifies a dataset and provides vital information pertaining
to it's use in GIS such as projection information, file format, and
the sources of the data. It also includes information about how to acquire
the data and where to contact for more information about the data. But
the real reason for metadata is to provide an answer to the most commonly
asked questions. If you have a question about data the first place to
look is in the metadata. The answer is usually there.
Identification Information
This includes the title, creator or originator of the data, an abstract describing the content of the dataset, keywords for search engines and a contact information for a person or organization for questions pertinent to the content or technical details about the data itself. If the data is available directly through download, a link is provided to the dataset here.
Data Quality Information
The Data Quality information contains information about the resolution or "scale" of the data, accuracy of the assignment of attributes and the georeferencing of the data. Important information in this section are descriptions of technical processes and citations for sources used in compiling the data whether they be hard copy maps that were digitized, tabular information included in a database, or digital data that was used in the creation of the current data. There is also contact information for further information about the source materials or processes involved in creating the data.
Spatial Data Organization Information
This tells the user whether this is vector or raster data and provides relevant details about the vector objects or pixel dimensions of raster data
Spatial Reference Information
A most important section this details the projection or coordinate system and associated modelling specifications necessary for using the data or determining the usefulness of the data.
Entity and Attribute Information
Provides an overview or detailed information on the attributes in the tables or fields in a database.
Distribution Information
This gives information about how the data is available. For data downloaded from the PASDA site the most relevant information will be the format of the data (Arc/Info Export, Shape-file, etc.) and what compression schemes, if any, have been applied to the data. For datasets that are not available online this section will also include the physical formats in which the data is available (CD-ROM, tape cartridge, etc.) and contact information describing where and how to acquire the data.
Metadata Reference Information
This is information about the format and creator of the metadata.
 |
 |