Related Resource References in CMR Metadata

Interim Collection Comparison Report for Big Earth Data Initiative

Metadata Source: NASA Common Metadata Repository

Metadata Dialect: ISO 19115-2

Evaluation Target: Related Online Resources

John Kozimor – The HDF Group 

The ESDIS Common Metadata Repository (CMR) recognizes the importance of referencing related online resources from the metadata. Related resource references are represented by the Related URL concept in the UMM-Common metadata model.

The table below shows the distribution of Related URL fields represented in ISO 19115-2 for CMR metadata collections. This table focuses on links for accessing distribution content for the resource described by the metadata. 

We examined 2158 metadata records from 16 collections extracted from the CMR during October 2015. A value of 1 or more typically (although not necessarily) indicates that the element is included one or more times in each record in a collection. A value < 1.0 is typically the percentage of records in a collection that include the metadata element. Empty cells which indicate a value of 0 are shaded in pink.  Pink cells indicate the element is completely missing from the collection.

The analysis below shows that Online Link URL elements are populated to some extent in all the collections evaluated.  The LARC collections show a completeness values of < then one, which indicates not all records in the collection include this field. Otherwise, all other CMR collections include at least 1 Online Link URL.  The Link Name and Link Description elements are missing from some of the collections. This may be an improvement focus area for those collections.  

Table 1:  Distribution of Related URL fields in CMR metadata collections