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Overview

This evaluation compares the usage of metadata items (elements and attributes) in NASA Collections with Other Collections.  The CMR includes metadata collections from 18 NASA providers and from 8 Other providers.  Other providers include non NASA agencies from around the world.

The CMR includes metadata that originate in three dialects: DIF, ECHO, and ISO. The largest portion of CMR collection records are in the SciOps collection, and are inserted into the CMR in DIF format. These are referred to here as the SciOps collection. The second largest portion of metadata for NASA collections originate from ECHO and are inserted into the CMR in ECHO format. These are referred to here as the NASA collection. A third group of metadata in the CMR originate from other agencies around the world and are generally either in DIF or possibly in ISO. These are referred to as the Other collection.

The DIF and ECHO dialects were originally developed to facilitate discovery of collections in the Global Change Master Directory or ECHO. The content of these “discovery” dialects is translated into the ISO dialects that are the eventual target for CMR. This translation is generally done without augmentation, so the content does not change very much.

Metadata providers have a choice about which metadata dialect(s) they use to submit metadata to the CMR. We compared the Other and NASA collections to understand how does this choice effects the metadata content. 

Data Selection

The table below shows the collection included in this evaluation as well as the record count for each collection.

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