Semantically enhancing SensorML with controlled vocabularies in the marine domain KOKKINAKI ALEXANDRA, BUCK JUSTIN, DARROCH LOUISE, JIRKA SIMON AND THE MARINE PROFILES FOR OGC SENSOR WEB ENABLEMENT STANDARDS TEAM
Funded by SenseOCEAN (FP7/2007–2013 under grant agreement No. 61414) Bridges (Horizon 2020 under grant agreement No 635359)
Overview
Introduction
SensorML’s flexibility
Vocabularies
Process
Next steps
Conclusion Introduction
The marine domain has started implementing Open Geospatial Consortium’s (OGC) Sensor Web Enablement (SWE) standards • Aim to: – make all types of sensors, transducers and sensor data repositories discoverable, accessible and useable via the Web • Include: – Sensor Model Language (SensorML), – Observations and Measurements (O&M), – Sensor Planning Service (SPS), – Transducer Markup Language (TML), – Sensor Alert Service (SAS), – Sensor Observation Service (SOS) and – Web Notification Service (WNS).
Ability of computer systems to Ability of computer systems to exchange data with SensorML process a syntax and exchange unambiguous, shared meaning information
• The main objective is to enable interoperability, first at the syntactic level and later at the semantic level (by using ontologies and semantic mediation), so that sensors and processes • can be better understood by machines, • utilized automatically in complex workflows, • and easily shared between intelligent sensor web nodes. Characteristics
• SensorML flexible enough to describe all types of sensors • “Soft typing” characteristic: – pre-define in schema every possible property – property types defined outside of the SensorML schema (typically within an online ontology) and then be used within SensorML as a value to the definition attribute.
Classify a Fast repetition rate fluorometer in SensorML to aid the rapid discovery of my sensors
SensorML
Identification Classification Keywords Capabilities Characteristics History References Documentation
Consequences
Soft typing • Different terms for the same meaning • Variations in the meaning of the same term • Terms not properly defined • Terms not resolvable • Many different ontologies with variations on the names of same terms • Terms not mapped with each other
Reduce interoperability and discoverability via the web.
SensorML ontology
• SensorML creators have created the SensorML ontology to list these terms, through the Marine Metadata Interoperability (MMI) project, which hosts an Ontology Registry and Repository hosting a number of small project specific controlled vocabularies. • Since different communities require different terminologies, the ontology can fulfill only a subset of the required concepts. Solution
“In order to achieve interoperability within and between various sensor communities, implementation of SensorML will require the definition of community specific semantics (within online dictionaries or ontologies) that can be utilized within the framework” [OpenGIS® Sensor Model Language (SensorML) Implementation Specification] Marine Community
SWE Marine Profiles
National Environmental Research Council 52 North Wiki for (NERC) Vocabulary Server 2.0 SWE Marine Profiles SWE Marine profiles
Group by partners from several projects and initiatives (AODN, BRIDGES, ENVRI+, EUROFLEETS /EUROFLEETS2, FixO3, FRAM, IOOS, Jerico/Jerico-Next, NeXOS, ODIP/ODIP II, RITMARE, SeaDataNet, SenseOcean, X-DOMES) Aim at developing marine profiles of OGC SWE standards • to serve as a common basis for OGC implementations
Controlled Vocabularies and NVS2.0
Controlled vocabularies: • In information science controlled vocabulary is a carefully selected list of words and phrases, which are used to tag units of information (document or work) so that they may be more easily retrieved by a search. NERC Vocabulary Server 2.0 (NVS2.0) • provides access to lists of standardized terms • machine and human readable • W3C Simple Knowledge Organisation System (SKOS), RDF/XML • Vocab Search, Vocab editor
Classify a Fast repetition rate fluorometer in SensorML to aid the rapid discovery of my sensors
Find sensors that are classified as fluorometers
Section: Classification Term: InstrumentType Vocabulary: NVS2.0 Value: L05::353 Term values
• Observable property: NVS2.0 Vocabulary P01, P07 • Instrument Type: NVS2.0 Vocabulary L05 • Platform Type: NVS2.0 Vocabulary L06 • Sensor Models: NVS2.0 Vocabulary L22 • Roles: NVS2.0 Vocabularies G04, C86 • Feature of Interest: NVS2.0 Vocabulary C19 • Manufacturer: NVS2.0 Vocabularies L35, C75
Term Definitions: Initial Process
Identified Collected common terms from terms under Members Revised and the SWE each section Post on the add/suggest Published on submit to the examples containing wiki corrections the web VMG SWE Marine title, on the wiki wiki definition, alt label SensorML
Identification Classification Keywords Capabilities Characteristics History References
Application Instrument Type Accuracy Data storage Calibration Data scientist domain
Call Sign Platform Type Damping ratio Height Decommissioning Manufacturer
ICES code Detection limit Housing material Delivery Operator Wiki SWE examples Long name Frequency Length Deployment Owner Member post on the Measurement Manufacturer Weight Failure wiki range PI
SSN ontology Model name Operating depth Width LoanEnd Technical Coordinator
SensorML examples Model Number Precision LoanStart OpenGIS® SensorML Implementation Serial number Resolution Loss Specification
Short name Response time Maintenance
UUID Selectivity Recovery
Unique ID Sensitivity RepairEnd
Version Survival depth RepairStart
WMO platform Upgrade number NVS collections for SensorML
Each SensorML section constitutes a vocabulary=collection in NVS • Described in SKOS and RDF/XML • Holds a unique URI • URI pattern: http://vocab.nerc.ac.uk/collection/XXX/current/ Each Collection consists of several terms=concepts Each term • Holds a unique URI • Resolves to RDF/XML • URI pattern: http://vocab.nerc.ac.uk/collection/XXX/current/CODE/
URI T itle http://vocab.nerc.ac.uk/collection/W03/current/ SensorML History Event Types http://vocab.nerc.ac.uk/collection/W04/current/ SensorML Capability Section Terms http://vocab.nerc.ac.uk/collection/W05/current/ SensorML Characteristic Section Terms http://vocab.nerc.ac.uk/collection/W06/current/ SensorML Classification Section Terms http://vocab.nerc.ac.uk/collection/W07/current/ SensorML Identification Section Terms http://vocab.nerc.ac.uk/collection/W08/current/ SensorML Contact Section Terms Process
Member posts on the wiki a If other members do suggestion/correction not disagree or Revised and posted Submitted to the under a section on the wiki to get VMG and published containing a title and Agree it is submitted final agreement on the web a definition for revision (alt label) Where next..
• External mappings to the SensorML ontology • Internal mappings to NVS2.0 terms • Process a list of terms that have been added on the wiki
Conclusions
SensorML’s soft typing characteristic • different versions of sensor descriptions • not interoperable • less discoverable Formalization of the required terms Publication in the form of controlled vocabularies • served by NVS2.0 • governed by group • maintained by British Oceanographic Data Centre (BODC)
Acknowledgment
This work is funded by the European projects • SenseOCEAN (FP7/2007–2013 under grant agreement No. 61414) • Bridges (European Union's Horizon 2020 research and innovation programme under grant agreement No 635359) Supported Ocean Data Interoperability Platform (ODIP) Supported by the National Environmental Research Council (NERC) National Capability (NC) funding for NC-services, facilities and data (NC-SFD). Useful Links
NVS2.0 SOAP service: http://vocab.nerc.ac.uk/vocab2.wsdl NVS2.0 RESTFul interface http://vocab.nerc.ac.uk/collection/ NVS2.0 SPARQL endpoint http://vocab.nerc.ac.uk/sparql/ NVS2.0 SensorML collections http://vocab.nerc.ac.uk/collection/W03/current/ http://vocab.nerc.ac.uk/collection/W04/current/ http://vocab.nerc.ac.uk/collection/W05/current/ http://vocab.nerc.ac.uk/collection/W06/current/ http://vocab.nerc.ac.uk/collection/W07/current/ http://vocab.nerc.ac.uk/collection/W08/current/