Metadata Protocols and Standards
For the purposes of the Global Change Master Directory (GCMD), metadata is defined as: "Descriptive information that characterizes a set of quantitative and/or qualitative measurements and distinguishes that set from other similar measurement sets.Controlled keywords are essential within the metadata to provide a normalized discovery for data through 10 sets of controlled keywords, and data-related services etc. and are required within the GCMD." (L. Olsen)
The metadata used by the GCMD is considered to be that set of attributes that are instrumental in helping users to determine if a data set meets their qualifications. The set of attributes (fields) and its associated syntax is known as the Directory Interchange Format (DIF). It has evolved over the years and serves the user community in the discovery of Earth science data.
In addition to the Directory Interchange Format (DIF) standard, the Global Change Master Directory staff works with other groups involved with promoting standards and has cross-mapped its valuable set of fields to other formats to synchronize content.
- The ISO
19115/TC 211 Geographic Information/Geomatics
- DIF to ISO 19115 Mapping
- North American Profile of ISO 19115:2003, Geographic information - Metadata
Unified Metadata Model (UMM)
- UMM models
- The Jakarta Lucene Search and Retrieval Protocol