Element Description
The Related URLs element provides access to resources related to a collection. The Related URL may also link to data access points, as well as relevant tools and services.
Note: This wiki page pertains to Related URLs in collection level metadata. For guidance on Related URLs in granule level metadata, please see the RelatedURLs (GRANULES) wiki page.
Best Practices
The Related URLs metadata element allows for the linkage of a metadata record to external resources or locations on the web. When used properly, this element allows users to quickly and easily access data, as well as access relevant services and information about the data. Related URLs at the collection level should point to:
- A data access location
- A landing page for the associated dataset
- Any relevant services provided for the data (if applicable) such as: Web Map Services (WMS), OPeNDAP, THREDDS, Web Map Tile Services (WMTS), Web Coverage Services (WCS), etc.
- A user's guide and/or comparable documentation which provides important information about how to use the data
- The project home page
- Relevant software packages
- Relevant online data tools
- Relevant PI documentation
- Read-Me files
- Data citation policies
- Algorithm Theoretical Basis Document (ATBD)
- OpenSearch Description Document (OSDD) links
- Any other documentation directly related to the dataset (examples include: data recipes, micro articles, product quality assessment documentation, important announcements, documentation on dataset anomalies, etc.)
There are two special sub-sections within Related URLs. These include the GET DATA and the USE SERVICE API sub-elements. A separate wiki page with full details has been developed for each of these sub-sections:
Related URLs (USE SERVICE API)
The details on this wiki page are for general Related URL guidance and do not include any of the GET DATA or USE SERVICE API sub-elements.
Several of the elements within the Related URLs section of the metadata serve to properly identify the purpose of the link. These identifying elements include:
URL Content Type: The URL Content Type is a keyword which, at a high level, describes the content of a link. This is a controlled vocabulary field maintained as an enumeration list within the UMM-Common schema with the following options: "CollectionURL", "PublicationURL", "DataCenterURL", "DistributionURL", "DataContactURL", "VisualizationURL". The URL Content Type helps specify how the URL will be displayed in the Earthdata Search Client.
URL Type: The URL Type is a keyword which specifies the content of a link. URL Type keywords are maintained in the Keyword Management System (KMS). A list of valid URL Type keywords can be found here: https://gcmd.earthdata.nasa.gov/kms/concepts/concept_scheme/rucontenttype?format=csv
Note that the keyword list does not include the upper level URL Content Type keywords (specified above & maintained in the UMM schema). Please see the diagram below for details on the relationship between URL Content Type keywords and URL Type keywords.
URL Subtype: The URL Subtype is a keyword which further specifies the content of a link. Together, the URL Type and Subtype keywords create a keyword hierarchy which is used to identify the URL. Providing a Subtype is optional, but should be used when applicable. The URL Subtype keywords are maintained in the Keyword Management System (KMS). A list of valid URL Subtype keywords can be found here: https://gcmd.earthdata.nasa.gov/kms/concepts/concept_scheme/rucontenttype?format=csv
Description: While not required, it is highly recommended that a description be provided for each URL provided in the metadata. The description should be kept brief and explain where the link navigates and the type of information it contains. Descriptions should be unique to the link. While descriptions can be repeated for the same type of URL across different metadata records, it is generally advised that the same description not be repeated within the same metadata record. i.e. the description should be used to further differentiate two URLs with the same URL Type and Subtype.
Examples:
URL: https://daac.ornl.gov/ACTAMERICA/guides/ACTAMERICA-PICARRO_Ground.html
URL Content Type: PublicationURL
URL Type: VIEW RELATED INFORMATION
URL Subtype: USER'S GUIDE
Description: The guide document contains detailed information about the dataset.
URL: https://ghrc.nsstc.nasa.gov/home/micro-articles/lake-effect-snow
URL Content Type: PublicationURL
URL Type: VIEW RELATED INFORMATION
URL Subtype: MICRO ARTICLE
Description: Learn about how AMSR-2 data can be used to study lake effect snow in this micro article.
Please see the below diagram for the full relationship between URL Content Type, Type, and Subtype keywords:
Element Specification
Related URLs is a required metadata element. At least 1 Related URL must be provided. Multiple URLs may be provided if necessary (Cardinality: 0..*).
Model | Element | Type | Usable Valid Values | Constraints | Required? | Cardinality | Notes |
---|---|---|---|---|---|---|---|
UMM-Common | RelatedUrls/URL | String | n/a | 1 - 1024 characters | Yes | 1 | |
UMM-Common | RelatedUrls/Description | String | n/a | 1 - 4000 characters | No | 0..1 | It is strongly recommended that a description be provided for each URL. |
UMM-Common | RelatedUrls/URLContentType | Enumeration | CollectionURL PublicationURL DataCenterURL DistributionURL DataContactURL VisualizationURL | n/a | Yes | 1 | The DataCenterURL option is only valid in the Data Centers section of the metadata. The DataContactURL option is only valid in the Data Contacts section of the metadata. |
UMM-Common | RelatedUrls/Type | String | GCMD URL Content Type 'Type' Keywords | KMS controlled | Yes | 1 | Each Type keyword corresponds to a specific URL Content Type category. |
UMM-Common | RelatedUrls/Subtype | String | GCMD URL Content Type 'Subtype' Keywords | KMS controlled | No | 0..1 | The Type and Subtype are part of a keyword hierarchy specified in the KMS. |
Metadata Validation and QA/QC
All metadata entering the CMR goes through the below process to ensure metadata quality requirements are met. All records undergo CMR validation before entering the system. The process of QA/QC is slightly different for NASA and non-NASA data providers. Non-NASA providers include interagency and international data providers and are referred to as the International Directory Network (IDN).
Please see the expandable sections below for flowchart details.
Dialect Mappings
UMM Migration
None
History
UMM Versioning
Version | Date | What Changed |
---|---|---|
1.17.1 | 8/10/2022 | No changes were made for RelatedURL during the transition from version 1.17 to 1.17.1 |
1.17 | 5/11/2022 | No changes were made for RelatedURL during the transition from version 1.16.7 to 1.17 |
1.16.7 | 3/2/2022 | No changes were made for RelatedURL during the transition from version 1.16.6 to 1.16.7 |
1.16.6 | 12/1/2021 | No changes were made for RelatedURL during the transition from version 1.16.5 to 1.16.6 |
1.16.5 | 7/13/2021 | Removed enumerations for RelatedURLContentType, RelatedUrlType, and RelatedURLSubtype values, and indicating that KMS should be the source of the values. |
1.16.4 | 6/30/2021 | Changed RelatedURL that adds HITIDE , SOTO , Sub-Orbital Order Tool , and CERES Ordering Tool as new enumerations to the subtype field. |
1.16.3 | 5/19/2021 | Changed RelatedURL that adds GET CAPABILITIES as a new enumeration to the type field and adds GIBS as a new subtype, opensearch already exists as a valid subtype. |
1.16.2 | 4/7/2021 | No changes were made for RelatedURL during the transition from version 1.16.1 to 1.16.2 |
1.16.1 | 4/7/2021 | No changes were made for RelatedURL during the transition from version 1.16.0 to 1.16.1 |
1.16.0 | 3/24/2021 | No changes were made for RelatedURL during the transition from version 1.15.5 to 1.16.0 |
1.15.5 | 12/3/2020 | No changes were made for RelatedURL during the transition from version 1.15.4 to 1.15.5 |
1.15.4 | 9/18/2020 | No changes were made for RelatedURL during the transition from version 1.15.3 to 1.15.4 |
1.15.3 | 7/1/2020 | No changes were made for RelatedURL during the transition from version 1.15.2 to 1.15.3 |
1.15.2 | 5/20/2020 | No changes were made for RelatedURL during the transition from version 1.15.1 to 1.15.2 |
1.15.1 | 3/25/2020 | No changes were made for RelatedURL during the transition from version 1.15.0 to 1.15.1 |
1.15.0 | 2/26/2020 | No changes were made for RelatedURL during the transition from version 1.14.0 to 1.15.0 |
1.14.0 | 10/21/2019 | No changes were made for RelatedURL during the transition from version 1.13.0 to 1.14.0 |
1.13.0 | 04/11/2019 | No changes were made for RelatedURL during the transition from version 1.12.0 to 1.13.0. |
1.12.0 | 01/22/2019 | During the transition from version 1.11.0 to 1.12.0, 4 new Related URL keywords were added. |
1.11.0 | 11/28/2018 | During the transition from version 1.10.0 to 1.11.0, the enumerations for sub elements 'Type' and 'Subtype' were changed to match the GCMD version of the keywords that was released on March 15, 2018. |
1.10.0 | 05/02/2018 | During the transition from version 1.9.0 to 1.10.0, the following sub elements were added: 'Mime Type' (Get Data) and 'Format' (Get Service). |
ARC Documentation
Version | Date | What Changed | Author |
---|---|---|---|
1.0 | 07/25/2018 | Recommendations/priority matrix transferred from internal ARC documentation to wiki space | Jeanne' le Roux |