Abstract

EPOS-DCAT-AP is an extension of the DCAT Application Profile for Research Infrastructures in Environmental and the solid-Earth domains.
The extension is developed and adopted in the framework of the European Plate Observing System (EPOS) in order to capture the diversity and heterogeneity of the assets provided by the EPOS community.
EPOS-DCAT-AP is based on DCAT-AP and uses or extends additional vocabularies (e.g., Schema.org, Hydra).

Disclaimer

The content of this document reflects only the author’s view and EPOS [[EPOS]] is not responsible for any use that may be made of the information it contains.

Overview

This document contains the specification for EPOS-DCAT-AP, an extension of the DCAT application profile1 for Research Infrastructures in the solid-Earth domain. It is developed in the framework of European Plate Observing System2 (EPOS). EPOS-DCAT-AP has been conceived to represent shared Core Concepts agreed within the EPOS communities. It supports the process of collection and organisation of knowledge from the EPOS Thematic Core Services (TCS) in order to create a shared information space and enable semantic interoperability.

Context

The European Plate Observing System [[EPOS]] is a pan-European Research Infrastructure (RI) for solidEarth sciences included in the Environmental Research Infrastructure Cluster (ENVRI).
A major challenge in EPOS is the integration of multi-disciplinary, multi-organisational, distributed resources and community resources into a single overarching Research Infrastructure - the EPOS Integrated Core Services (ICS). ICS aggregate and harmonise descriptions of datasets, data products, software and services provided by different Thematic Core Services (TCS). TCS adopt heterogeneous formats, vocabularies, protocols, and standards to represent and make their assets available. In order to capture, organise and harmonise information from different sources and to enable semantic interoperability through exchanges of metadata between ICS and TCS, an application profile based on DCAT-AP has been developed, namely EPOS-DCAT-AP [[EPOS-DCAT-AP]].
EPOS-DCAT-AP is the result of a collaborative work that brought together diverse expertise which aims at increasing accessibility and usability of multidisciplinary data to researchers and other stakeholders.

EPOS-DCAT-AP is adopted successfully in EPOS, however, the set of requirements addressed make this model suitable to be adopted by other Research Infrastructures and to be applied in different contexts.

Scope of this document

A DCAT-AP extension

The EPOS-DCAT-AP specification is designed as an extension of DCAT-AP in conformance with the guidelines for the creation of DCAT-AP extensions [[DCAT-AP-EG]].

The DCAT-AP Application Profile on which this document is based is the DCAT-AP specification v1 [[DCAT-AP]].

Profile Encoding

The encoding of the EPOS-DCAT-AP [[EPOS-DCAT-AP]] provides the technical aspects used for data representation and exchange, ensuring interoperability. An influential choice for achieving interoperability across diverse systems is the adoption of RDF (Resource Description Framework) and the Turtle format. RDF's structure allows for a flexible and standardized representation of data, promoting a harmonized approach to information exchange.

The preference for Turtle [[Turtle]] as a data exchange format is based on its simplicity and human-readable nature. This choice is crucial for promoting a consistent and clear representation of data, fitting well with the RDF model.

Finally, a Turtle document serves as a textual representation of an RDF graph, offering a compact yet expressive format for articulating the complexities of the graph. An RDF graph, built on triples consisting of a subject, predicate, and object, forms the backbone of this interoperable and standardized representation.

Revision history

In 2023, the adoption of W3C DCAT 3 triggered a new alignment for DCAT-AP. W3C DCAT 3 extends the profile with the Dataset Series notion, deprecates the use of some URIs and introducing new URIs in the DCAT namespace for the use case of Dataset versioning.

Terminology used in the Application Profile

A Vocabulary s a specification that determines the semantics of terms (classes and properties) in a broad context of information exchange. The defined terms are highlyhigly reusable.

An Application Profile is a specification that re-uses terms from one or more base standards (vocabularies), adding more specificity by identifying mandatory, recommended and optional elements to be used for a particular application, as well as recommendations for controlled vocabularies to be used.

In the following sections, classes and properties are grouped under headings ‘mandatory’, ‘recommended’ and ‘optional’. These terms have the following meaning:

The meaning of the terms MUST, MUST NOT, SHOULD and MAY in this section and in the following sections are as defined in [[RFC2119]].

Namespaces

The namespace for EPOS-DCAT-AP is: https://www.epos-eu.org/epos-dcat-ap

The namespace prefix is: epos

The Application Profile reuses terms from various existing specifications, following established best practices [[?DWBP]]. The following table indicates the full list of corresponding namespaces used in this document.

Application Profile Overview

shows a UML diagram of the classes and properties included in the EPOS-DCAT-AP.

EPOS-DCAT-AP UML Class Diagram
EPOS-DCAT-AP UML Class Diagram

Application Profile Classes

Mandatory Classes

Optional Classes

Additional classes for EPOS-DCAT-AP

The following classes are included in [[EPOS-DCAT-AP]]:

Equivalent classes for EPOS-DCAT-AP

The following classes are defined as equivalent classes for [[EPOS-DCAT-AP]]:

Application Profile Properties per Class

A quick reference table of properties per class is included in 4.37 Quick Reference of Classes and Properties. The list of included properties contains all the properties in [[DCAT-AP]], plus a selection of properties from other vocabularies on which EPOS-DCAT-AP expresses additional constraints or on which EPOS-DCAT-AP wants to emphasise their usage.

Examples on the use of these properties, encoded in [[Turtle]], are included in the relevant sections and available from a separate folder.

Class: Address

Mandatory properties

Example

Class: Agent

Mandatory property

Class: ApiDocumentation

Mandatory properties

Class: Catalog

Mandatory properties

Optional properties

Class: CatalogRecord

Mandatory properties

Optional properties

Class: Category

Mandatory properties

Example

Class: CategoryScheme

Example

Class: Checksum

Mandatory properties

Class: ContactPoint

Optional properties

Example

Class: Dataset

Mandatory properties

Optional properties

Example

Class: Distribution

Mandatory properties

Optional properties

Example

Class: Document

Class: Equipment

Mandatory properties

Optional properties

Example

Class: Facility

Mandatory properties

Optional properties

Example

Class: Identifier

Mandatory properties

Example

Class: IriTemplate

Mandatory properties

Optional properties

Example

Class: IriTemplateMapping

Mandatory properties

Optional properties

Example

Class: Kind

Class: LicenseDocument

Class: Location

Optional properties

Example

Class: Media Type or Extent

Class: Operation

Optional properties

Example

Class: Organization

Mandatory properties

Optional properties

Example

Class: PeriodOfTime

Example

Class: Person

Mandatory properties

Optional properties

Example

Class: PostalAddress

Mandatory properties

Example

Class: Project

Mandatory properties

Optional properties

Class: PropertyValue

Mandatory properties

Example

Class: ProvenanceStatement

Class: Publication

Mandatory properties

Optional properties

Class: RightsStatement

Class: Standard

Class: Service

Mandatory properties

Optional properties

Example

Class: SoftwareApplication

Mandatory properties

Optional properties

Example

Class: SoftwareSourceCode

Mandatory properties

Optional properties

Example

Class: WebService

Mandatory properties

Optional properties

Example

Quick Reference of Classes and Properties

This version of EPOS-DCAT-AP extends [[DCAT-AP]] with additional classes and properties (some of which re-used across classes). They are listed in the following table marked with a prepended “plus” sign (+).