Maine GIS & FGDC

Maine GIS Uses FGDC Metadata

Maine GIS has adopted the Federal Geographic Data Committee (FGDC), "Content Standard for Digital Geospatial Metadata" (CSDGM), as a documentation or "metadata" standard for geospatial data. Maine GIS data documented with FGDC metadata is published through the Maine GIS Internet Data Catalog and is made available to the national clearinghouse nodes of the National Spatial Data Infrastructure (NSDI) and the US Geological Survey National Map. Data developers are responsible for providing documentation in FGDC format for each digital map added to the Maine GIS database. The metadata must be stored and maintained by the contributor or agency responsible for developing and maintaining the data.

Why FGDC Metadata?

Metadata is "data about data". Like a style guide, the FGDC CSDGM defines what information belongs in a metadata record and the format in which the information is presented. The goals and objectives of the Maine GIS FGDC compliant documentation can be summarized as follows:

  • to provide a history of each Maine GIS geospatial data set with standardized information on content, location, purpose, accuracy, condition, quality, collection, development processes, scale, projection, feature attributes, and other characteristics of geospatial data necessary to determine the utility of a map for a specific purpose
  • to protect Maine's investment in geospatial data, by minimizing the risk of data loss and the re-creation of existing data, through systematized documentation of geospatial information
  • to promote data sharing by providing information about Maine GIS data holdings to external catalogues, clearinghouses, and brokerages and by providing information on the processing and interpretation of spatial data received through a transfer from an external source

Basics of FGDC

Federal Geographic Data Committee (FGDC) metadata answers the who, what, where, when, how and why questions of geospatial data. The data structure and elements defined for FGDC metadata are described fully in the "Content Standard for Digital Geospatial Metadata" (CSDGM). A CSDGM Workbook provides specific help and examples for the completion of each FGDC element and is available at https://www.fgdc.gov/metadata/csdgm-standard.

Questions always arise about "How much of this information is required?" or "Can't the process be simplified for our purposes?". The best responses to these questions and others can be found at https://www.fgdc.gov/standards/faqs. This site "Frequently asked questions on FGDC metadata" contains much good discussion on the topic. To quote a few important points:

  • "Document at a level that preserves the value of the data within your organization. Consider how much you would like to know about your data sets if one of your senior GIS operators left suddenly." (FAQ, p.5)
  • "Don't invent your own standard. There already is one. Try to stay within its constructs. Subtle changes from the CSDGM...can be costly in the long run-you may not be able to use standard metadata tools and your metadata may not be exchangeable."(FAQ, p.4)
  • "?The costs and value of metadata, to both immediate and longer-term operations, should be evaluated at the start. Judgment also is needed on deciding what information about source materials should be retained. Documenting existing or "legacy" data can be daunting. Details are long forgotten and costs can be high. These concerns are valid, but care should be taken to avoid allowing issues related to legacy data to unduly influence the documentation of new data."(CSDGMWkbk, p.8)

Seven Sections of FGDC

The Federal Geographic Data Committee (FGDC), Content Standard for Digital Geospatial Metadata (CSDGM) organizes a metadata record into seven main sections:

  • Identification Information,
  • Data Quality Information,
  • Spatial Data Organization Information,
  • Spatial Reference Information,
  • Entity and Attribute Information,
  • Distribution Information,
  • Metadata Reference Information.

These sections are constructed from both simple and compound data elements. A simple element is a stand-alone unit of metadata. Compound elements may consist of a group of related simple elements and/or compound elements. A type of compound element exists in the elements "Citation Information" and/or "Contact Information". These elements record a set of information related to specific data authors, publishers, process contacts, sources, and metadata contacts, for reuse in various sections of a metadata document and throughout a metadata collection.

FGDC Content

The following questions provide examples of the type of information required to complete the content development of the seven sections of Federal Geographic Data Committee (FGDC) metadata:

Identification Information

What is the name of the dataset?
What is the subject or theme of the information included?
What is the scale of the dataset?
What are the attributes of the dataset?
Where is the geographic location of the dataset?
Who developed the dataset?
Who provided the source material for the dataset?
Who will publish the dataset?
When were the features of the dataset identified?
How are the features of the dataset depicted?
Why was the data set created?
Are there restrictions on accessing or using the data?
Are external files available that are related to the dataset?

Data Quality Information

How reliable are the data?
What are its limitations or inconsistencies?
What is the positional and attribute accuracy?
Is the dataset complete?
Were the consistency and content of the data verified?
Where can the sources of the data be located?
What processes were applied to these sources and by whom?

Spatial Data Organization

What spatial data model was used to encode the spatial data?
How many and what kind of spatial objects are included in the dataset?
Are methods other than coordinates, such as street addresses used to encode locations?

Spatial Reference

Are coordinate locations encoded using longitude and latitude?
What map projections is used?
What horizontal datum and/or vertical datum are used?
What parameters should be used to convert the data to another coordinate system?

Entity and Attribute Information

What geographic information (roads, houses, elevation, temperature, etc.) is described?
How is this information coded?
What do the codes mean?
What source was used for defining the attributes or codes, i.e. Cowardin classification?

Distribution

From whom can the data be obtained?
What formats are available?
What media are available?
Are the data available online?
What is the price of the data?

Metadata Reference

When were the metadata compiled, and by whom?
When was the metadata record created?
Who is the responsible party?
When were the metadata last updated?

Maine GIS FGDC Initiatives

Two FGDC compliant metadata tools are in common use among Maine GIS users: ESRI's ArcGIS ArcCatalog metadata tool suite and SMMS Spatial Metadata Management System from Intergraph. While all FGDC metadata has a standard exchangeable format, the usability and limitations of various tools for metadata creation affect the way the metadata, will be stored and the structure built-into a metadata tool affects the subsequent use of the metadata. In considering the selection of a metadata tool it is important to evaluate other organizational needs such as metadata update, management, publication, coordination and data sharing.

ArcCatalog metadata tools are freely available to anyone using ArcGIS software, therefore this is the tool of choice for many Maine GIS users. ArcCatalog metadata tools use a file based system and store metadata as an embedded .xml file within the geospatial data format, i.e. geodatabase, shapefile. Metadata can be viewed, created, edited, imported and exported from ArcCatalog in a variety of formats. In addition to the FGDC "classic" format, ArcCatalog metadata can be viewed in a variety of style sheets all built on the native xml format. The file based system lends itself well to browsing associated metadata within ESRI software. The system is less easily suited for handling enterprise wide metadata tasks like the standardization of contact, citation, keyword information. Among the exportable FGDC compliant formats, the CSDGM TXT format is most easily portable to other FGDC compliant tools.

The Maine Office of GIS (MEGIS), in cooperation with Maine's GIS Executive Council and the GIS Technical Group, has purchased two licenses of Spatial Metadata Management System (SMMS) software for metadata creation and management. SMMS is a platform independent, database supported tool from Intergraph. SMMS provides database capabilities to search evaluate, locate and load, catalog, and synchronize data holdings. The tool is used at MEGIS to create, update, and maintain an entire catalog of Maine GIS metadata from data contributed to the Maine GIS database by Maine GIS users. FGDC compliant ASCII text files imported into SMMS from a variety of sources are stored by MEGIS in an Oracle database at the Office of Information Technology. The Maine GIS Internet Data Catalog provides data selection, description and query directly from this database. In addition FGDC Encoded ASCII text files and html format files are exported from the database to refresh the Maine GIS MEGIS.<SDE> and the Maine GIS server directory at /home11/crypt83/metadata/fgdc. A directory of metadata files served to the Internet makes all Maine GIS data available to a variety of national clearinghouse sites, including the USGS National Map and the FGDC NSDI clearinghouse.

A number of other commercial software products, as well as some free metadata tools, are available for the development of FGDC compliant metadata. Among these are the U.S. Army Corps of Engineers' Corpsmet95, Metamaker from the Upper Midwest Environmental Sciences Center (Biological Resources Division, U.S. Geological Survey), and the metadata toolkit, utilities available from USGS. Others are packaged with GIS software. For further information and evaluation of metadata tools see https://www.fgdc.gov/metadata/geospatial-metadata-tools.

Technical Support for FGDC Metadata Development in Maine

The Maine Office of GIS (MEGIS) provides technical support to state agencies and the public for content development of FGDC metadata and information on FGDC compliant software for metadata development is available through the Maine Office of GIS, Data Center, Technical Support phone line at (207) 624-7700.

More About FGDC

Federal Geographic Data Committee (FGDC) metadata is the required documentation of all geospatial data products produced through partnerships, grants or contracts with federal agencies. Federal agencies collecting or producing geospatial data, either directly or indirectly (e.g. through grants, partnerships, or contracts with other entities), are required to ensure, prior to obligating funds for such activities, that data will be collected in a manner that meets all relevant standards adopted through the FGDC process. (Executive Order 12906, published in the April 13, 1994, edition of the Federal Register, Volume 59, Number 71, pp. 17671-17674. COORDINATING GEOGRAPHIC DATA ACQUISITION AND ACCESS: THE NATIONAL SPATIAL DATA INFRASTRUCTURE)

FGDC metadata documents are also the basic components of the National Geospatial Data Clearinghouse, and FGDC compliant metadata for Maine GIS geospatial data can be made available to clearinghouse nodes nationwide. The National Geospatial Data Clearinghouse is a distributed online catalog of digital spatial data, part of the National Spatial Data Infrastructure (NSDI) (Executive Order 12906). NSDI goals are to reduce duplication of effort among agencies, improve quality and reduce costs related to geographic information, to make geographic data more accessible to the public, to increase the benefits of using available data, and to establish key partnerships with states, counties, cities, tribal nations, academia and the private sector to increase data availability.

 

References

Federal Geographic Data Committee. Content Standard for Digital Geospatial Metadata Workbook Version 2.0. Federal Geographic Data Committee. Washington, D.C.

Federal Geographic Data Committee. FGDC-STD-001-1998. Content Standard for Digital Geospatial Metadata (revised June 1998). Federal Geographic Data Committee. Washington, D.C.

Maine Office of Geographic Information Systems. Data Standards for Maine Geographic Information Systems. Maine Department of Administrative and Financial Services, Bureau of Information Services, Augusta, Maine.

RTSe, 2000. Spatial GIS Metadata/Data Manager, User Guide, Version 3.1 for Oracle 8. RTSe USA, Redmond, Washington.

FGCD Data Checker: https://statuschecker.fgdc.gov/