DGIWG Metadata Registry

Metadata is data about data and is one of the basic elements of geographic information. Metadata has been central to the work of DGIWG since its earliest development of the DIGEST exchange standard, and is an important aspect of many other geographic information standards. DGIWG began working on metadata many years ago and participated extensively in the work of ISO TC211 on project 19115 Metadata. A significant part of the work was led by DGIWG experts.

DGIWG agreed to the study on metadata as part of the DGIWG suite of standards first by the development of a requirements report. The scope of the work was to establish a "DGIWG metadata standard profile registry that contains the register of ISO 19115 and ISO 19115-2 and any extensions identified in the DGIWG Metadata Profile of ISO 19139 for use by military coalitions ". The report "Metadata_Registery_Requirements" specifies the requirements for such a register. It is a general report that also addresses other registration issues.

Geospatial metadata describes a geospatial dataset. In describing a geospatial dataset, a number of common information elements are required that can be defined using a discrete domain of values. Though the membership of the domain is not fixed over time (i.e. domain elements are added and retired as community requirements change), it is important for the domain values to be uniquely identified and with persistent definitions for consistent metadata implementation in support of interoperability. In addition, geospatial data is expensive to produce and can have a long shelf life, so it is important that the metadata remain intelligible.

Registries provide a mechanism to document a domain of values specific to one or more information elements. For geospatial metadata, a number of general purpose domains have been identified that require documentation to ensure consistent metadata implementations.