Support collections defined within geospatial metadata

[philipashlock]

Currently collections can be defined within metadata using the Project Open Data Metadata schema, but this is not currently supported with geospatial metadata. Currently the only way geospatial metadata can be organized into collections is if the children in the collection have their own separate WAF harvest source with that harvest source manually registered as a collection.

[philipashlock]

To date this had been suggested (and documented in the crosswalk) using the following fields in ISO 19115 as equivalents to map from isPartOf. It looks like others (e.g. here or here) have used parentIdentifier to create parent/child relationships just like we use isPartOf in the Project Open Data Metadata Schema.

1. larger work identifier //gmd:identificationInfo/gmd:MD_DataIdentification/gmd:aggregationInfo/gmd:MD_AggregateInformation/gmd:aggregateDataSetIdentifier/gmd:MD_Identifier/gmd:code (gco:CharacterString or gmx:Anchor) + //gmd:identificationInfo/gmd:MD_DataIdentification/gmd:aggregationInfo/gmd:MD_AggregateInformation/gmd:associationType/gmd:DS_AssociationTypeCode == largerWorkCitation
2. larger work title //gmd:identificationInfo/gmd:MD_DataIdentification/gmd:aggregationInfo/gmd:MD_AggregateInformation/gmd:aggregateDataSetName/gmd:CI_Citation/gmd:title + //gmd:identificationInfo/gmd:MD_DataIdentification/gmd:aggregationInfo/gmd:MD_AggregateInformation/gmd:associationType/gmd:DS_AssociationTypeCode == largerWorkCitation
3. parent identifier //gmd:parentIdentifier (gco:CharacterString or gmx:Anchor)

[JJediny]

For reference: http://schemas.opengis.net/

[LyndaW]

Summary of resolution as documented in 'Geospatial Metadata Recommendations Supporting Discovery and Use in Data.gov and the Geospatial Platform' vers. 20170302 (pending publication to https://cms.geoplatform.gov/resources)

• Create metadata records for both the collection and collection members utilizing Reference Identifiers and referencing the collection-level metadata record within the member metadata records using 'Aggregation Information' (ISO 19115-1), 'Associated Resource Information' (ISO 19115-1), or 'Larger Work Citation' (CSDGM)
• place all the member metadata records in a single WAF separate from the collection-level metadata record
• register the WAF that includes the member metadata records as a "WAF Homogeneous Collection” Harvest Source in catalog.data.gov
• provide agency-specific URLs for the following Harvest Source registration elements: URL:provide a link to the WAF that contains the member metadata records Collection Metadata URL: provide a link to the collection-level metadata record

[kvuppala]

Below are suggestions from Geo-spatial team on metadata vs data resource identifiers for consideration

Metadata vs Data (resource) Identifiers

Metadata Record Identifiers MD_Metadata elements are specific to the metadata record ISO 19115 (these are the elements that Data.gov is currently using - only fileIdentifier) MD_Metadata.fileIdentifier - Metadata record of resource being documented MD_Metadata.parentIdentifier - Metadata record from which the current metadata record is a ‘subset’ ISO 19115-1 (note names have been changed on both to make relationship more clear) MD_Metadata.metadataIdentifier MD_Metadata.parentMetadata

A metadata record can be the child of another metadata record without being a child of the resource (dataset, service, etc.) that the metadata record represents.

For example, a metadata record may be the child (subset) of an organizational metadata record (parent) that contains contacts, liability and constraint language, distribution methods, QA/QC methods, etc.). It is good data management practice to create subset metadata records and separate fixed (parent) and dataset-specific (child) metadata and compile upon publication. In this way, fixed information can be updated in one place (parent metadata record) vs. each associated (child) metadata record.

Data (resource) Identifiers MD_Identification elements are specific to the resource being documented (data, service, etc.), e.g. Resource Identifier MD_Identification>Citation.identifier Parent (or other association) Resource Identifier 19115: MD_Idenfication.aggregationInfo>MD_AggregateInformation. aggregateDataSetName>Citation.identifier 19115-1: MD_Idenfication.associatedResource>MD_AssociatedResource.name

Citation.identifier And MD_AssociatedResource.type (LargerWorkCitation, partOfSeamlessDatabase, collectiveTitle, series)

NOTE that type = is ComposedOf can be used to indicate child resources

If the Data.gov objective is to identify resources that have parent/.child, and other relations, e.g. a data collection and a member of that collection, then the MD_Identification>Citation.identifier would be the more appropriate identifier to document that relation.

May be that the MD_Metadata.fileIdentifier may be best to uniquely identify the metadata record and the resource identifiers used to document parent/child relations between resources.