1. ECS Metadata Considerations for Preservation SiriJodha S. Khalsa National Snow and Ice Data Center

2. A Little History ECS = NASA's Earth Observing System (EOS) Data and Information System (EOSDIS) Core System Data model based on FGDC Content Standard for Digital Geospatial Metadata  CSDGM became basis of ISO 19115 ECS data model became basis of RS extension to FGDC  which was used in 19115-2

3. The ECS Metadata Model Bounded set of attributes (287 originally) intended to cover essential characteristics of all earth science data sets Granule-level (inventory) and Collection (catalog/discovery) metadata

4. ECS Metadata Types In addition:  Archival Metadata: Product-specific metadata that accompanies the granule when it is delivered to the data users, but need not be searchable by the system.  Structural Metadata: describes the specific data structures within the granule, including information necessary for geolocation of the data. Only in Data Product  Subsystem Persistent Metadata: Metadata generated by each subsystem to help identify, process and track objects in the system

5. Metadata provides information to:  Identify (title, origin, contents)  Locate (position, date & time)  Interpret (descriptions, units & scaling factors, accuracy)  Document (software version, production history, ancillary inputs)

6. Production System (as originally planned) SCF Data Product Generation Metadata ECS Ancillary Data Ancillary Data Collection and Granule, AutoQA, PH ESDT

7. Production System (as it evolved) SIPS Data Ingest Metadata ECS Ancillary Data Ancillary Data ESDT

8. Location of Metadata ECS Databases  Ingest, data pool, archive, etc. HDF-EOS Data Files Distributed metadata files Online documentation (DAACs, Instrument Team & Product Team Websites)

9. Issues DAACs will not alter original files (and therefore the metadata they contain)  QA updates only in distributed metadata, so metadata can get out of sync Metadata spread across several different ECS databases, DAAC websites, the product itself  How gather for preservation?