NASA’s Common Metadata Repository (CMR) is a high-performance, high-quality repository for Earth science metadata records that is designed to handle metadata at the Concept level. Collections and granules are common concepts in the Earth observation world, but this can be extended to visualizations, parameters, documentation, services, and more. CMR metadata records are supplied by a diverse array of data providers using a variety of supported metadata standards including ECHO 10, DIF 9, DIF 10, ISO 19115-1, and ISO 19115-2.
NASA's Unified Metadata Model (UMM) is an extensible metadata model that provides a cross-walk for mapping between CMR-supported metadata standards. Each CMR-supported metadata standard is mapped centrally to the UMM model, thus reducing the number of translations required. UMM describes metadata related to key Earth Observing System Data and Information System (EOSDIS) concepts such as collection or granule using UMM metadata “profiles." Each UMM profile is a document that provides a schema-agnostic representation of the elements necessary to provide high quality metadata for its related EOSDIS concept and that maps those elements to each CMR-supported metadata standard. To date, there are seven profiles described in the UMM:
- Collections (UMM-C)
- Granules (UMM-G)
- Services (UMM-S)
- Variables (UMM-Var)
- Visualizations (UMM-Vis)—planned, publication date to be determined
- Elements Common to multiple UMM component models (UMM-Common)