Alignment to om-lite

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A. Alignment to om-lite OWL implementation of Observations and Measurements

This Annex describes the alignment of SOSA/SSN to the [OM-Lite] OWL2 implementation of OGC Observations and Measurements [OandM].

O&M was originally specified as a UML model, following the patterns specified in ISO 19109 Geographic Information - Rules for Application Schema [ISO-19109]. [OM-Lite] is a handcrafted implementation of O&M in idiomatic OWL.

The first section below describes a basic mapping between om-lite (OWL for Observations) and sam-lit (OWL for Sampling Features) and SOSA, comparable to the mapping to [OandM] described in the normative part of the specification. The subsequent two sections describe extensions to SOSA to match the semantics of the om-lite and sam-lite ontologies that were described in [OM-Lite]. These graphs demonstrate how om-lite and sam-lite could be re-built by extending SOSA both vertically (adding axioms to SOSA classes) and horizontally (adding new classes and properties, including sub-classes and properties of SOSA classes and properties).

A.1 Alignment to om-lite implementation of Observations and Measurements

The following namespace prefixes are used in the alignment to SOSA.

Prefix Namespace
sosa: http://www.w3.org/ns/sosa/
sosa-oml: http://www.w3.org/ns/sosa/oml#
oml: http://def.seegrid.csiro.au/ontology/om/om-lite#
samfl: http://def.seegrid.csiro.au/ontology/om/sam-lite#

Utility classes

Five utility classes are defined locally to support the formalization of the alignment.

1. Three disjoint subclasses of sosa:Procedure:

sosa-oml:ActuationProcedure Actuation procedures or recipes
sosa-oml:ObservationProcedure Observation procedures or recipes
sosa-oml:SamplingProcedure Sampling, sample preparation or processing procedures or recipes

2. Two classes related to sampling, which complement SOSA classes related to actuation and observation:

sosa-oml:SamplingDevice Sampling, sample preparation or processing devices, comparable to sosa:Actuator and sosa:Sensor
sosa-oml:SamplingEvent Sampling, sample preparation or processing event or act, comparable to sosa:Actuation and sosa:Observation

Class alignments

The primary classes from [OM-Lite] have direct equivalents in SOSA classes supplemented by the utility classes described above, as follows:

oml:Observation equivalent class sosa:Observation
oml:Process equivalent class sosa:Sensor or sosa-om:ObservationProcedure
samfl:SamplingFeature equivalent class sosa:Sample
samfl:Process equivalent class sosa-om:SamplingDevice or sosa-om:SamplingProcedure

Property alignments

The following properties from [OM-Lite] have direct equivalents in SOSA properties:

oml:featureOfInterest equivalent property sosa:hasFeatureOfInterest
oml:observedProperty equivalent property sosa:observedProperty
oml:phenomenonTime equivalent property sosa:phenomenonTime
samfl:sampledFeature equivalent property sosa:isSampleOf

Additional alignments from [OM-Lite] properties to SOSA are as follows.

oml:procedure sub-property of sosa:usedProcedure
samfl:samplingMethod sub-property of sosa:usedProcedure
oml:result sub-property of sosa:hasResult
oml:resultTime sub-property of sosa:resultTime
samfl:samplingTime sub-property of sosa:resultTime

These are modeled as sub-properties because sosa:usedProcedure, sosa:hasResult and sosa:resultTime applies to actuation, observation or sampling activities.

samfl:hostedProcedure sub-property of sosa:hosts

This is modeled as a sub-property because the domain of iso19156-sfs:SF_SpatialSamplingFeature.hostedProcedure is a spatial sampling feature, such as a station, rather than a more general platform.

An RDF file containing a graph corresponding to this alignment is available.

A.2 Extension of SOSA to match om-lite

The RDF file oml-extension-of-sosa.ttl provides an extension of SOSA to match the full semantics of the observation ontology om-lite described in [OM-Lite]. Additional classes, properties and sub-classes and sub-properties of SOSA classes and proeprties are defined, as well as some restrictions on SOSA classes and properties, to achieve the same expressivity as om-lite. The namespace https://www.w3.org/ns/oml-on-sosa/ is used for new resources in this vertical extension to SOSA.

(more here if agreed)

A.3 Extension of SOSA to match sam-lite

The RDF file samfl-extension-of-sosa.ttl provides an extension of SOSA to match the full semantics of the sampling ontology sam-lite described in [OM-Lite]. Additional classes, properties and sub-classes and sub-properties of SOSA classes and proeprties are defined, as well as some restrictions on SOSA classes and properties, to achieve the same expressivity as sam-lite. The namespace https://www.w3.org/ns/sam-on-sosa/ is used for new resources in this vertical extension to SOSA.

(more here if agreed)