Federal Geographic Data Committee  •  www.fgdc.gov   

                               Email: fgdc@fgdc.gov    

 

GEOSPATIAL METADATA 

JULY 2011

Federal Geographic Data Committee is charged 

in OMB Circular A-16 to implement the six basic 

building blocks of the NSDI: metadata, 

clearinghouse, standards, framework, geospatial 

data, and partnerships. Metadata, as a critical 

component of the NSDI, allows for the 

documentation, discovery, 

assessment, integration, distribution, 

and archival of geospatial resources. 

Metadata is defined by the New 

Merriam-Webster Dictionary as “data 

that provides information about other 

data”. Geographic metadata is used 

to document the attributes of 

geographic data, e.g. database files 

and data develop within a Geographic 

Information System (GIS), in the 

same way that the nutrition label to 

the right documents the attributes of a 

food product. 

Geographic metadata seeks to 

answer questions such as: Who 

developed the data? When was the 

data collected? How were the data 

processed? How are the data 

attributes defined? In what formats 

are the data available? How does one 

obtain the data? The information in the metadata 

provides context for the data and supports the 

effective application of the data. 

METADATA STANDARDS 

The FGDC currently supports multiple metadata 

standards. The Content Standard for Digital 

Geospatial Metadata (CSDGM) is the long time 

FGDC endorsed geographic metadata standard. 

However, the U.S. is in the process of adopting 

and implementing the International Standards 

Organization (ISO) geographic metadata 

standard (19115). ISO metadata implementation 

has been gradual as users explore the 

application of the standard and make 

recommendations for changes. Once the latest 

version of the international standard (ISO 19115-

1) is stable, the North American Profile (NAP) of 

ISO 19115 will be updated and the FGDC and 

other organizations will offer updated 

tools, training materials and guidance 

documents to support ISO metadata 

implementation. 

What’s different between the CSDGM 

and ISO geographic metadata 

standards? Not that much. ISO 19115, 

like the CSDGM, is based on a 

standard achieved through 

consensus. The ISO standard, 

however, is based on the consensus 

of the international community while 

CSDGM consensus was limited to 

U.S. Federal agencies. As a result, 

the ISO metadata standard better 

supports data sharing across national 

and cultural boundaries. Within the 

ISO standard, code lists (fixed 

domains) are used more often to 

control vocabulary, thereby improving 

search capability. Some metadata 

components, such as Maintenance 

Information, are enhanced and the 

new standard supports the documentation of 

data portals, web mapping applications and other 

web services. 

What’s new with content of the standard? 

Optional elements are employed to a greater 

degree within the ISO standard making it more 

flexible than the CSDGM. This flexibility enables 

organizations to better customize the standard to 

meet their own needs. FGDC recommends that 

each organization/agency develop a 

standardized template to support the 

implementation of their customized metadata 
Federal Geographic Data Committee  •  www.fgdc.gov   

                               Email: fgdc@fgdc.gov    

‘profile’ and to serve as a guide for agency 

metadata creation. 

Unlike the CSDGM, the ISO metadata standard 

integrates parts of other geographic data 

standards. Some components of information 

such as the entity attribute descriptions, referred 

to as ‘Feature Catalog’, are actually defined by a 

different standard and are therefore only 

referenced from the metadata record. ISO 

19115-1 improves upon the integration of 

Feature Catalog information and the subsequent 

NAP effort intends to further explore options for 

coupling the information. 

The formats of the standards also differ. While 

the CSDGM was written as a text document, ISO 

metadata was created using the Unified Modeling 

Language (UML), a standardized general 

purpose modeling language often used in 

software engineering. Through its companion 

Technical Specification (ISO 19139), the ISO 

metadata standard is represented in a consistent 

Extensible Markup Language (XML) format for 

use worldwide. As such, the ISO data model is 

more easily, and consistently, reproduced within 

software applications that support metadata 

creation and content validation. 

What are the core components of a metadata 

record? 

Metadata Record Information - information about 

the metadata record including the language in 

which the record is written, a unique file identifier 

for the metadata record, the metadata standard 

used to organize the record, a point of contact for 

the metadata record, and the date that the 

metadata record written. 

Identification Information – citation-level 

information about the data including the title, 

abstract, purpose for creation, status, keywords 

(theme and place), and extent (temporal, vertical 

and horizontal). 

Constraints Information – information about legal 

and security limitations to data access and use. 

Data Quality Information – information about the 

processes and sources used to develop the data 

and positional and/or accuracy assessments 

performed. 

Maintenance Information – information about the 

scope and frequency of data updates. 

Spatial Representation – information about the 

mechanism used to represent spatial data (grid, 

point, vector). 

Reference System Information – information 

about the reference systems used to represent 

geographic position and time. 

Content Information – information about the data 

set entities and attributes. 

Symbology Information – information about the 

symbols used to represent spatial features. 

Distribution Information – information about the 

data distributors and methods for obtaining the 

data. 

Metadata Extension Information – information 

about custom, user-based, changes to the 

elements, domains or conditionality of the 

standard. 

Application Schema Information – information 

about the schema or data models used to 

structure the data. 

FGDC member agencies are actively exploring 

ISO metadata implementation. To learn more 

about these efforts and to access the FGDC 

guidance document, Preparing for International 

Metadata, visit the FGDC Metadata Program 

website at: http://www.fgdc.gov/metadata. 

 

Additional Information 

Available on-line at www.fgdc.gov/metadata

or contact us at fgdc@fgdc.gov or visit the 

FGDC website at www.fgdc.gov.