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Upgrading Metadata from GBL 1.0 to OGM Aardvark


Table of contents

  1. Full crosswalk table
  2. Elements without a crosswalk
  3. Tools and techniques for upgrading

Full crosswalk table

Most of the elements from GBL 1.0 can be crosswalked directly into OGM Aardvark. The values for these elements are the same - only the URI name has changed or the field has been converted to an array.

The following chart shows the full Aardvark schema and which GBL 1.0 fields can be directly mapped.

# Label GBL 1.0 OGM Aardvark Note
01 Title dc_title_s dct_title_s new namespace
02 Alternative Title   dct_alternative_sm new field
03 Description dc_description_s dct_description_sm new namespace; single to multi-valued
04 Language dc_language_s or _sm dct_language_sm new namespace; single to multi-valued
05 Creator dc_creator_sm dct_creator_sm new namespace
06 Publisher dc_publisher_s dct_publisher_sm new namespace; single to multi-valued
07 Provider dct_provenance_s schema_provider_s new URI name
08 Resource Class   gbl_resourceClass_sm new field
09 Resource Type   gbl_resourceType_sm new field
10 Subject dc_subject_sm dct_subject_sm new namespace
11 Theme   dcat_theme_sm new field
12 Keyword   dcat_keyword_sm new field
13 Temporal Coverage dct_temporal_sm dct_temporal_sm no change
14 Date Issued dct_issued_s dct_issued_s no change
15 Index Year solr_year_i gbl_indexYear_im new URI name; single to multi-valued
16 Date Range   gbl_dateRange_drsim new field
17 Spatial Coverage dct_spatial_sm dct_spatial_sm no change
18 Geometry solr_geom locn_geometry new field
19 Bounding Box solr_geom dcat_bbox new field
20 Centroid   dcat_centroid new field
21 Relation   dct_relation_sm new field
22 Member Of   pcdm_memberOf_sm new field
23 Is Part Of   dct_isPartOf_sm new value type (see Elements without a crosswalk)
24 Source dc_source_sm dct_source_sm new namespace
25 Version   dct_isVersionOf_sm new field
26 Replaces   dct_replaces_sm new field
27 Is Replaced By   dct_isReplacedBy_sm new field
28 Rights   dct_rights_sm new field
29 Rights Holder   dct_rightsHolder_sm new field
30 License   dct_license_sm new field
31 Access Rights dc_rights_s dct_accessRights_s new URI name
32 Format dc_format_s dct_format_s new namespace
33 File Size   gbl_fileSize_s new field
34 WxS Identifier layer_id_s gbl_wxsIdentifier_s new URI name
35 References dct_references_s dct_references_s no change
36 ID layer_slug_s id new URI name
37 Identifier dc_identifier_s dct_identifier_sm new namespace; single to multi-valued
38 Modified layer_modified_dt gbl_mdModified_dt new URI name
39 Metadata Version geoblacklight_version gbl_mdVersion_s new URI name
40 Suppressed suppressed_b gbl_suppressed_b new namespace
41 Georeferenced   gbl_georeferenced_b new field

Elements without a crosswalk

There are three elements in GBL 1.0 that do not directly translate into OGM Aardvark. While they have been replaced with similar fields in OGM Aardvark, the values themselves would need to be altered during crosswalking.

Type (dc_type_s)

  • GBL 1.0 Description: This single-valued GBL 1.0 field observes the Dublin Core controlled vocabulary for Type, including Dataset, Image, Collection, Interactive Resource, or Physical Object.
  • Similar Aardvark element: This has been replaced in Aardvark with the multi-valued Resource Class, which uses a custom controlled vocabulary of Collections, Datasets, Imagery, Maps, Web services, and/or Other.

Geometry Type (layer_geom_type_s)

  • GBL 1.0 Description: This single-valued GBL 1.0 field differentiates between vector (Point, Line, Polygon), raster (Raster, Image), non-spatial formats (Table), or a combination (Mixed).
  • Similar Aardvark element: This has been replaced in Aardvark with the multi-valued Resource Type, which uses a controlled vocabulary drawn from Library of Congress cartographic genres and GIS geometries.

Is Part Of (dct_isPartOf_sm)

  • GBL 1.0 Description: This multi-valued GBL 1.0 plain text field is for writing out the name of a collection. Example: dct_isPartOf_sm:"Village Maps of India"
  • Similar Aardvark element: The URI is the same in Aardvark, but it is now a non-literal field. The value must be one or more IDs that reference another record within the system. Example: dct_isPartOf_sm:"princeton-z603r079s"

Tools and techniques for upgrading

XSLTs for ISO and FGDC

New XSLTs to transform from ISO 19139 or FGDC to OGM Aardvark will be available here: https://github.com/OpenGeoMetadata/GeoCombine/tree/main/lib/xslt

Programmatic conversion of JSON files

This basic Python script can batch convert GBL 1.0 json files to OGM Aardvark. However, note the three elements listed above that do not have direct crosswalks.

Spreadsheet manipulation

This technique combines automatic conversions and manual edits:

  1. Convert your GBL 1.0 metadata files to a CSV.
  2. Manually augment and adjust values using spreadsheet functions.
  3. Convert your spreadsheet to OGM Aardvark JSONs.