Linked Open Data for European Earth Observation Products Carlo Matteo Scalzo CTO, Epistematica epistematica

Linked Data: a set of guidelines for publishing structured data on the Web Open Data: data derived from public founded research should be public resource Linked Open Data: the best way to publish data epistematica Linked Open Data for European Earth Observation Products#2 Linked Open Data

Benefits of Linked Open Data easy access for both human AND machines (HTML & SPARQL) + standard format for structured data (RDF) = data economy epistematica #3Linked Open Data for European Earth Observation Products

Data Economy : ESA “GMES provides a strong opportunity as a market driver for EO Services. Industry can exploit opportunities using GMES products & services in other markets, e.g., commercial, export and non-EU government.” EARSC, Digital Agenda Assembly 2012, Brussels OGC r3: candidate standard for “GeoSPARQL - A Geographic Query Language for RDF Data” epistematica #4Linked Open Data for European Earth Observation Products

Data Economy : NASA “The Open Data project is part of the NASA Open Government Initiative, and is intended to improve access to NASA data. This data catalog is a continually-growing listing of publicly available NASA datasets.” epistematica #5Linked Open Data for European Earth Observation Products

epistematica #6 Data Economy: Web Of Data Linked Open Data for European Earth Observation Products

Metadata: Linked Data Web Access: Semantic + Geospatial + Search EO Products epistematica #7Linked Open Data for European Earth Observation Products

Metadata: Linked Data Web Access: Semantic + Geospatial + Search EO Products humans machines epistematica #8Linked Open Data for European Earth Observation Products

Linked Data for EO Resources Each resource (e.g., EO product) is represented by a set of RDF triples epistematica #9 EO Product RDF Triple RDF (Resource Description Framework) is a W3C Standard based on XML Linked Open Data for European Earth Observation Products

Linked Data for EO Resources A triple is a statement about the resource, in the form epistematica #10 product URIattribute URI literal value or resource URI Linked Data uses HTTP URIs (Uniform Resource Identifier) Examples: Examples: Linked Open Data for European Earth Observation Products

Linked Data: Vocabularies Predicates are defined in vocabularies (RDF, SKOS, OWL, …) Predicates can be used to represent attributes of EO products as described by the standards (e.g., OGC) RDF triples can be used to represent geo-spatial metadata epistematica #11 Linked Open Data for European Earth Observation Products

EO Ontologies Predicates can also be used to link products to ontologies (SKOS, OWL, …) RDF triples can be used to represent semantic metadata epistematica #12 Linked Open Data for European Earth Observation Products

Metadata: Linked Data Web Access: Semantic + Geospatial + Search EO Products humans machines epistematica #13Linked Open Data for European Earth Observation Products

Metadata: Linked Data EO Products epistematica #14 First Step: RDF for EO Products Linked Open Data for European Earth Observation Products

Metadata: Linked Data epistematica #15 Second Step: Web Access Linked Open Data for European Earth Observation Products

Metadata: Linked Data epistematica #16 Third Step: Ontology Navigation Linked Open Data for European Earth Observation Products

Metadata: Linked Data Web Access: Semantic + Geospatial + Search EO Products humans machines epistematica #17Linked Open Data for European Earth Observation Products

First Step: RDF for EO Products ① Define a EO Vocabulary to specify technical attributes of EO products ② Develop a OGC-to-EO Vocabulary parser to create RDF Triples for each EO Product (one parser for each supported OGC standard) epistematica #18 EO Product RDF Triple Linked Open Data for European Earth Observation Products

First Step: RDF for EO Products ③ Extend the EO Vocabulary to link EO products to EO ontologies ④ Add RDF triples for each EO product to link the product with the ontologies (e.g., Multi-Domain Thesaurus) epistematica #19 EO Product RDF Triple Linked Open Data for European Earth Observation Products

Metadata: Linked Data EO Products epistematica #2020 First Step: RDF for EO Products ⑤ Store the RDF triples in a RDF Triple Store Linked Open Data for European Earth Observation Products

Triple Stores Triple Stores are databases optimized for the storage and retrieval of triples Many commercial implementations available: AllegroGraph, Virtuoso, Oracle, … epistematica #21 Metadata: Linked Data Linked Open Data for European Earth Observation Products

epistematica #22 triple stores can store and retrieve billions of triples Linked Open Data for European Earth Observation Products

Metadata: Linked Data Web Access: Semantic + Geospatial + Search EO Products humans machines epistematica #23Linked Open Data for European Earth Observation Products

Metadata: Linked Data epistematica #24 Second Step: Web Access Linked Open Data for European Earth Observation Products

Second Step: Web Access ① Create a web portal by using CKAN CKAN is an open-source data portal platform developed by the Open Knowledge Foundation “CKAN is aimed at data publishers (national and regional governments, companies and organizations) wanting to make their data open and available” ckan.org epistematica #25Linked Open Data for European Earth Observation Products

CKAN CKAN is already used for national and international data portals: epistematica #26 publicdata.eu (European Union) data.gov.uk (UK Government) Linked Open Data for European Earth Observation Products

Second Step: Web Access Portals created with CKAN provide many built-in functionalities, including:  “Google-style” search  map visualization and geospatial search epistematica #27Linked Open Data for European Earth Observation Products

Second Step: Web Access The web portal created by using CKAN provides access to metadata about EO products (RDF triples in the triple store) The portal also contains information on how to download EO products epistematica #28Linked Open Data for European Earth Observation Products

Metadata: Linked Data Web Access: Semantic + Geospatial + Search EO Products humans machines epistematica #29Linked Open Data for European Earth Observation Products

Metadata: Linked Data epistematica #3030 Third Step: Ontology Navigation Linked Open Data for European Earth Observation Products

Third Step: Ontology Navigation ① Integrate the Multi-Domain Navigator ( with CKAN epistematica #31Linked Open Data for European Earth Observation Products

Multi-Domain Navigator epistematica #32 the Multi-Domain Navigator is a graphical user interface that allows users to explore a EO ontology (the Multi-Domain Thesaurus) users can select an Application Term to obtain a list of all the EO products that are relevant for that Application the Multi-Domain Navigator makes it easy to access and discover EO products Linked Open Data for European Earth Observation Products

Multi-Domain Navigator and CKAN The user explores the ontology and selects an Application Term (e.g., Land Monitoring) The user obtains a list of relevant EO products By selecting an EO product from the list, the user can see the related information as shown by CKAN (including how to download the product) epistematica #33Linked Open Data for European Earth Observation Products

Metadata: Linked Data Web Access: Semantic + Geospatial + Search EO Products humans machines epistematica #34Linked Open Data for European Earth Observation Products

Metadata: Linked Data Web Access: Semantic + Geospatial + Search EO Products epistematica #35Linked Open Data for European Earth Observation Products

epistematica #36 Linked Open Data for European Earth Observation Products