Database Reference
In-Depth Information
focus on earth and environmental data (a vast majority of the data col-
lected by sensors). The
Semantic Sensor Network (SSN)
ontology [119]
is an OWL ontology developed by the W3C Semantic Sensor Network In-
cubator group (the SSN-XG) [119] to describe sensors and observations.
The SSN ontology can describe sensors in terms of their capabilities,
measurement processes, observations and deployments. The SSN ontol-
ogy development working group (SSN-XG) targeted the SSN ontology
development towards four use cases, namely (i) Data discovery and link-
ing, (ii) Device discovery and selection, (iii) Provenance and diagnosis,
and (iv) Device operation, tasking and programming. The SSN ontology
is aligned with the DOLCE Ultra Lite (DUL)
upper ontology
[39] (an up-
per ontology is an ontology of more generic, higher level concepts that
more specific ontologies can anchor their concepts to) . This has helped
to normalize the structure of the ontology to assist its use in conjunction
with ontologies or linked data resources developed elsewhere. DUL was
chosen as the upper ontology because it is more lightweight than other
options, while having an ontological framework and basis. In this case,
qualities, regions and object categories are consistent with the group's
modeling of SSN. The SSN ontology itself, is organized, conceptually
but not physically, into ten modules as shown in
Figure 12.5
.
The SSN
ontology is built around a central Ontology Design Pattern (ODP) de-
scribing the relationships between sensors, stimulus, and observations,
the Stimulus-Sensor- Observation (SSO) pattern. The ontology can be
seen from four main perspectives:
A sensor perspective, with a focus on what senses, how it senses,
and what is sensed.
An observation perspective, with a focus on observation data and
related metadata.
A system perspective, with a focus on systems of sensors and de-
ployments.
A feature and property perspective, focusing on what senses a
particular property or what observations have been made about a
property.
The full ontology consists of 41 concepts and 39 object properties,
directly inherited from 11 DUL concepts and 14 DUL object proper-
ties. The ontology can describe sensors, the accuracy and capabilities of
such sensors, observations and methods used for sensing. Concepts for
operating and survival ranges are also included, as these are often part
of a given specification for a sensor, along with its performance within
