implementedBy
type: ObjectProperty
inverse of: implements
definition: link from a requirement linked to an element in a UML model to an RDFS/OWL class or property which implements it

Battery
subclass of: System
definition: A Battery powering a System as its primary or secondary power source. As this is a specialization of the System class modeling of integrated battery management systems is also possible.

Material Sample
type: Class
implements: MaterialSample
subclass of: Sample
definition: subset of a FeatureOfInterest that is physical (i.e., tangible)
example: A piece of rock, a blood sample, a water sample, etc.
note: MaterialSamples may be destroyed in connexion with the observation act or a subsequent preparation step.
note: MaterialSamples that are curated and preserved are sometimes known as 'specimens'.

Normal Operating Conditions
type: Class
subclass of: Operating Conditions
definition: Type of observation or observation collection that describe the conditions under which a system is expected to operate normally.

Result
type: Class
subclass of: Restriction
  on property: is result of
  some values from: Execution of a Procedure
deprecated: true
definition: outcome of an Observation, Actuation, or act of Sampling. To store an observation's simple result value one can use the hasSimpleResult property.
example: The value 20 as the height of a certain tree together with the unit, e.g., Meter.

Spatial Sample
type: Class
implements: SpatialSample
subclass of: Sample
definition: subset of a FeatureOfInterest defined by its location and shape in space When observations are made to estimate properties of a geospatial feature, particularly where the value of a property varies within the scope of the feature, a SpatialSample is used.
example: Some common names for spatial samples include: borehole, flightline, interval, lidar cloud, map horizon, microscope slide, mine level, mine, observation well, profile, quadrat, scene, section, ship track, spot, station, swath, trajectory, traverse, etc...
note: Depending on accessibility and on the nature of the expected property variation, a SpatialSample may extend in one, two or three spatial dimensions.

Statistical Sample
type: Class
implements: StatisticalSample
subclass of: Sample
definition: subset of a FeatureOfInterest defined by the statistical process used to create it
example: The male or female subset of a population.
note: StatisticalSamples usually apply to populations or other sets, of which a certain subset may be of specific interest.

Suboptimal Conditions
type: Class
subclass of: Operating Conditions
definition: Type of observation or observation collection that describe the conditions under which a system is expected to operate sub-optimally. Results will still be reported but the performance of the sensor, in term of precision for example, will be impaired.

Survivable Conditions
type: Class
subclass of: Operating Conditions
definition: Type of observation or observation collection that describe the conditions under which a system is expected to survive, that is to continue to exist in its current form, even if its future operations are impaired. A typical example is the temperature at which a sensor looses physical integrity and looses its shape. A system or sensor exposed to conditions outside of those reported by SurvivableConditions will no longer be serviceable.

end time
type: DatatypeProperty
domain includes: Actuation
domain includes: Actuation Collection
domain includes: Deployment
domain includes: Execution of a Procedure
domain includes: Execution Collection
comment: The value would usually be encoded using xsd:dateTime xsd:date xsd:gYearMonth xsd:gYear
definition: instant of time when the Execution or Deployment was ended or completed

has operating conditions
type: ObjectProperty
domain includes: Actuator
domain includes: Sampler
domain includes: Sensor or Observer
domain includes: System
range includes: Observation
range includes: Observation Collection
range includes: Operating Conditions
definition: Relation between a System and its Operating Conditions, modelled as ObservationCollection (or Observation) describing conditions under which the System can operate. A short but extensible list of sub-classes of OperatingConditions is provided in SSN-System, such as normal operating conditions, suboptimal conditions, and survivable conditions.

has simple result
type: DatatypeProperty
type: FunctionalProperty
domain includes: Actuation
domain includes: Actuation Collection
domain includes: Execution of a Procedure
domain includes: Execution Collection
domain includes: Observation
domain includes: Observation Collection
implements: result-sem
definition: relation from an Execution to its value expressed as a literal In the case of an Actuation, the result may be the value of the Property following the execution of the Procedure by the Actuator. In the case of an Observation, the result is the value of the Property produced by the execution of the Procedure by the Sensor.
example: For instance, the values 23 or true.
note: This DatatypeProperty provides an alternative to hasResult, to be used only if the execution result can be expressed as a Literal

has system capability
type: ObjectProperty
domain includes: Actuator
domain includes: Sampler
domain includes: Sensor or Observer
domain includes: System
range includes: Observation
range includes: Observation Collection
definition: Relation between a System and an ObservationCollection (or Observation) describing the capability of the system. A sensor or system may have more than one set of system capabilities with different validity contexts.

has validity context
type: ObjectProperty
domain includes: Observation
domain includes: Observation Collection
domain includes: Property
range includes: Observation
range includes: Observation Collection
definition: Links a an observation collection or observation (typically about the system capabilities) or a property (typically about the system capabilities) to its validity context, described as an observation collection or observation (typically about the system environment).

input value for execution
type: ObjectProperty
range includes: Actuation
range includes: Actuation Collection
range includes: Execution of a Procedure
range includes: Execution Collection
range includes: Observation
range includes: Sampling
inverse of: has input value
definition: relation from an input value to an Execution that used it

is ultimate feature of interest of
type: ObjectProperty
domain includes: Feature Of Interest
range includes: Actuation
range includes: Actuation Collection
range includes: Deployment
range includes: Execution of a Procedure
range includes: Execution Collection
range includes: Observation
range includes: Observation Collection
range includes: Sampling
range includes: Sampling Collection
inverse of: has ultimate feature of interest
definition: relation from an ultimate FeatureOfInterest to an Execution, Execution Collection, or Deployment, for which it is the ultimate subject

made on platform
type: ObjectProperty
domain includes: Observation
domain includes: Observation Collection
range includes: Platform
implements: host-sem
definition: Relation between an Observation and the Platform the Sensor was attached to at the time the observation was made.

observation type
type: ObjectProperty
domain includes: Observation
implements: type-sem
definition: Information providing further detail on the type of Observations.

prepared sample
type: ObjectProperty
domain includes: Preparation Step
range includes: Sample
implements: preparedSample-sem
definition: The Sample on which the PreparationProcedure is performed.

processing details
type: ObjectProperty
domain includes: Preparation Step
range includes: Preparation Procedure
implements: processingDetails-sem
definition: The PreparationProcedure used by the PreparationStep.

related sampling
type: ObjectProperty
domain includes: Sampling
range includes: Sampling
implements: relatedSampling-sem
definition: Relation to an act of Sampling.

sample preparation step
type: ObjectProperty
domain includes: Preparation Procedure
range includes: Preparation Step
implements: samplePreparationStep-sem
definition: A PreparationStep that uses the PreparationProcedure.

valid time
type: ObjectProperty
domain includes: Observation
domain includes: Observation Collection
domain includes: Sampling
range includes: PeriodOfTime
range includes: Interval
implements: validTime-sem
definition: The time interval during which the result is assumed to be applicable for use.

result time
type: DatatypeProperty
domain includes: Execution of a Procedure
domain includes: Execution Collection
domain includes: Observation
domain includes: Observation Collection
domain includes: Sampling
domain includes: Sampling Collection
implements: resultTime-sem
comment: The value would usually be encoded using xsd:dateTime xsd:date xsd:gYearMonth xsd:gYear
definition: instant of time when the Execution was completed

start time
type: DatatypeProperty
domain includes: Actuation
domain includes: Actuation Collection
domain includes: Deployment
domain includes: Execution of a Procedure
domain includes: Execution Collection
domain includes: Observation
domain includes: Observation Collection
domain includes: Sampling
domain includes: Sampling Collection
comment: The value would usually be encoded using xsd:dateTime xsd:date xsd:gYearMonth xsd:gYear
definition: instant of time when the Execution or Deployment was initiated or tasked

SSN Ontology - actuation module
type: Ontology
created: 2024-02-02
creator: W3C/OGC Spatial Data on the Web Working Group
description: Actuation classes and properties for the SSN Ontology.
description: Actuation classes and properties for the SSN Ontology. This module adds RDFS and OWL axioms to the terms defined in SOSA Actuation
license: Software
license: copyright-software-and-document
rights: Copyright 2025 W3C/OGC.
title: Sensor, Observation, Sample, and Actuator (SOSA) Ontology - actuation module
imports: Sensor, Observation, Sample, and Actuator (SOSA) Ontology - actuation module
imports: SSN Ontology - core module

OMS Ontology - based on (SOSA) Ontology with SSN axiomatization
type: Ontology
created: 2023-12-06
creator: W3C/OGC Spatial Data on the Web Working Group
description: This ontology is based on the SOSA Ontology by the W3C/OGC Spatial Data on the Web Working Group, supplemented by some classes and properties required to implement ISO 19156:2023 , with axiomatization following SSN.
license: Software
license: copyright-software-and-document
rights: Copyright 2025 W3C/OGC.
source: 20-082r4.html
comment: Vertical module adding SSN-style axioms to the SOSA-OMS module
imports: OMS Ontology - based on (SOSA) Ontology
imports: Sensor, Observation, Sample, and Actuator (SOSA) Ontology - actuation module

implements
type: ObjectProperty
sub property of: source
sub property of: wasDerivedFrom
definition: link from an RDFS/OWL class or property to a requirement linked to an element in a UML model which it implements

feature has ultimate sample
type: ObjectProperty
domain includes: Feature Of Interest
range includes: Sample
range includes: Sample Collection
inverse of: has sampled feature
definition: relation from an ultimate FeatureOfInterest to a Sample or SampleCollection that is intended to be representative of it; i.e., the end of a chain of hasSample relations

has input
type: ObjectProperty
domain includes: Procedure
inverse of: input for
definition: relation from a Procedure to an input required for its execution
note: This property will typically describe the type of the inputs required to execute the Procedure.
scope note: An input might be a calibration or conditioning parameter, or the output of a previous procedure within an extended processing chain.

has input value
type: ObjectProperty
domain includes: Actuation
domain includes: Actuation Collection
domain includes: Execution of a Procedure
domain includes: Execution Collection
domain includes: Observation
domain includes: Sampling
definition: assigns a value to an input defined by the Procedure that is used in an Execution
note: The input value MUST be consistent with a hasInput definition from the corresponding Procedure
scope note: The input might be a calibration or conditioning parameter, or the output of a previous procedure within an extended processing chain.

has output
type: ObjectProperty
domain includes: Procedure
inverse of: output for
definition: relation from a Procedure to an output of its execution
note: This property will typically describe the type of the result from executing the Procedure.

has procedure
type: ObjectProperty
domain includes: Property
range includes: Procedure
sub property of: property for
inverse of:
  sub property of: for property
definition: relation from a Property to a Procedure that can observe or act on it

has proxy
type: ObjectProperty
domain includes: Property
range includes: Stimulus
inverse of: is proxy for
definition: relation from an Property to a Stimulus that serves as its proxy
example: For example, the expansion of mercury is a Stimulus that serves as a proxy for some temperature Property. An increase or decrease in the velocity of spinning cups on a wind Sensor is serving as a proxy for the wind speed.

input for
type: ObjectProperty
range includes: Procedure
inverse of: has input
definition: relation from an input to a Procedure that uses it in an Execution

is member of collection
type: ObjectProperty
domain includes: Actuation
domain includes: Actuation Collection
domain includes: Execution of a Procedure
domain includes: Execution Collection
domain includes: Observation
domain includes: Observation Collection
domain includes: Sample
domain includes: Sample Collection
domain includes: Sampling
domain includes: Sampling Collection
range includes: Actuation Collection
range includes: Execution Collection
range includes: Observation Collection
range includes: Sample Collection
range includes: Sampling Collection
inverse of: has member of collection
definition: link from an Execution or Sample or Collection of these, to a collection that it is part of
editorial note: Note that there is a single `member` property. OWL or SHACL constraints may limit the range depending on the context of different collection types
scope note: rules for the consistency of values of properties of collections and properties of their members are given for each collection type

is original sample of
type: ObjectProperty
domain includes: Sample
range includes: Sample
range includes: Sample Collection
inverse of: has original sample
definition: relation from the initial Sample collected from the ultimate FeatureOfInterest to a downstream Sample or SampleCollection

made sampling has result
type: ObjectProperty
domain includes: Sampler
range includes: Sample
range includes: Sample Collection
inverse of: is a result of made by sampler
property chain axiom: made sampling
property chain axiom: has result
definition: relation from a Sampler to a Sample or SampleCollection made by it

observation related to
type: ObjectProperty
domain includes: Observation
domain includes: Observation Collection
range includes: Execution of a Procedure
range includes: Execution Collection
inverse of: related observation
definition: relation from an Observation or ObservationCollection to another Execution or ExecutionCollection
scope note: This general relationship complements the specific predicates outbound from Observation. It is particularly useful to relate Observations (and collections) to other Executions (and collections)

has preparation step
type: ObjectProperty
domain includes: Sample
range includes: Preparation Step
implements: preparationStep-sem
definition: Link to a preparation step used to prepare the sample

output for
type: ObjectProperty
range includes: Procedure
inverse of: has output
definition: relation from an output to a Procedure that generates it in an Execution

phenomenon occurred
type: ObjectProperty
domain includes: TemporalEntity
range includes: Actuation
range includes: Actuation Collection
range includes: Execution of a Procedure
range includes: Execution Collection
range includes: Observation
range includes: Sampling
inverse of: phenomenon time
definition: result of an Execution that this time applies to

phenomenon time
type: ObjectProperty
domain includes: Actuation
domain includes: Actuation Collection
domain includes: Execution of a Procedure
domain includes: Execution Collection
domain includes: Observation
domain includes: Observation Collection
domain includes: Sampling
domain includes: Sampling Collection
range includes: TemporalEntity
implements: phenomenonTime-sem
inverse of: phenomenon occurred
definition: time that the result of an Execution applies to the subject entity It may be an interval or an instant, or some other compound temporal entity [[!owl-time]].
scope note: The phenomenonTime is not necessarily the same as the resultTime. In the case of Actuation, phenomenonTime SHOULD indicate the time during which the actuator was active. In the case of Observation, the phenomenonTime MAY be distant from the resultTime. For example in the case of forecasts the phenomenonTime is after the resultTime. In historical, geological and cosmological investigations the phenomenonTime can be far in the past, while the resultTime is contemporary. In the case of Sampling the phenomenonTime SHOULD indicate the time during which the Sampling Procedure was active. The resultTime can indicate when the sample comes into the posession of the operator.

quality of
type: ObjectProperty
range includes: Observation
range includes: Observation Collection
inverse of: observation result quality
definition: link from a quality description to an Observation or ObservationCollection that it relates to

related observation
type: ObjectProperty
domain includes: Execution of a Procedure
domain includes: Execution Collection
range includes: Observation
range includes: Observation Collection
implements: relatedObservation-sem
inverse of: observation related to
definition: relation from an Execution or ExecutionCollection to an Observation or ObservationCollection
scope note: This general relationship complements the specific predicates inbound to Observation. It is particularly useful to relate Observations (and collections) to other Executions (and collections)

observation result quality
type: ObjectProperty
domain includes: Observation
domain includes: Observation Collection
implements: resultQuality-sem
inverse of: quality of
definition: relation from an Observation or ObservationCollection to some information pertaining to the quality of the result
note: The quality of a result can be assessed following the procedures in the ISO 19157 series.
note: dqv:hasQualityMeasurement from the Data Quality Vocabulary is equivalent
scope note: This instance-specific description complements the description of the observation Procedure, which provides information concerning the quality of all observations using this procedure. Multiple measures can be provided.

used for execution has result
type: ObjectProperty
domain includes: Sampling Procedure
range includes: Sample
range includes: Sample Collection
inverse of: is a result of used procedure
property chain axiom: used for execution
property chain axiom: has result
definition: relation from a Procedure to a Sample or SampleCollection made by it

Sensor, Observation, Sample, and Actuator (SOSA) Ontology - actuation module
type: Ontology
created: 2024-02-02
creator: W3C/OGC Spatial Data on the Web Working Group
description: Observation classes and properties for the SSN Ontology.
license: Software
license: copyright-software-and-document
rights: Copyright 2025 W3C/OGC.
imports: Sensor, Observation, Sample, and Actuator (SOSA) Ontology - actuation module
imports: SSN Ontology - core module

Sensor, Observation, Sample, and Actuator (SOSA) Ontology - actuation module
type: Ontology
created: 2024-02-02
creator: W3C/OGC Spatial Data on the Web Working Group
description: Sampling classes and properties for the SSN Ontology.
license: Software
license: copyright-software-and-document
rights: Copyright 2025 W3C/OGC.
imports: Sensor, Observation, Sample, and Actuator (SOSA) Ontology - actuation module
imports: SSN Ontology - core module

acts on
type: ObjectProperty
domain includes: Actuator
range includes: Property
sub property of: for property
inverse of: is acted on by
definition: relation from an Actuator to a Property whose state may be changed by using it
example: In the activity (Actuation) of automatically closing a window if the temperature in a room drops below 20 degrees Celsius, the property upon which the Actuator acts is the state of the window as it changes from being open to being closed.

deployed on platform
type: ObjectProperty
domain includes: Deployment
range includes: Platform
implements: host-sem
sub property of: deployed asset
inverse of: in deployment
definition: relation from a Deployment to a Platform on which Systems are hosted

deployed system
type: ObjectProperty
domain includes: Deployment
range includes: Actuator
range includes: Sampler
range includes: Sensor or Observer
range includes: System
implements: observer-sem
sub property of: deployed asset
inverse of:
  sub property of: has deployment
definition: relation from a Deployment to a deployed System

detects
type: ObjectProperty
domain includes: Sensor or Observer
range includes: Stimulus
inverse of: is detected by
definition: relation from a Sensor to the Stimulus that it detects The Stimulus itself will be serving as a proxy for some Property.

has property
type: ObjectProperty
domain includes: Feature Of Interest
range includes: Property
inverse of: is property of
definition: relation from an entity to a Property of that entity

has sample
type: ObjectProperty
domain includes: Feature Of Interest
range includes: Sample
inverse of: is sample of
definition: relation from a FeatureOfInterest to the Sample or SampleCollection used to represent it

has subsystem
type: ObjectProperty
domain includes: Actuator
domain includes: Sampler
domain includes: Sensor or Observer
domain includes: System
range includes: Actuator
range includes: Sampler
range includes: Sensor or Observer
range includes: System
inverse of: is subsystem of
definition: relation from a System to its component parts

hosts
type: ObjectProperty
domain includes: Platform
range includes: Actuator
range includes: Platform
range includes: Sampler
range includes: Sensor or Observer
range includes: System
inverse of: is hosted by
property chain axiom: in deployment
property chain axiom: deployed system
definition: relation from a Platform to an asset (System or Platform) hosted or mounted on it

is acted on by
type: ObjectProperty
domain includes: Property
range includes: Actuator
inverse of: acts on
definition: relation from a Property to an Actuator that may change its state
example: In the activity (Actuation) of automatically closing a window if the temperature in a room drops below 20 degrees Celsius, the property upon which the Actuator acts is the state of the window as it changes from being open to being closed.

is detected by
type: ObjectProperty
domain includes: Stimulus
range includes: Sensor or Observer
inverse of: detects
definition: relation from a Stimulus to a Sensor that may detect it The Stimulus itself will be serving as a proxy for some Property.

is feature of interest of
type: ObjectProperty
domain includes: Feature Of Interest
range includes: Actuation
range includes: Actuation Collection
range includes: Deployment
range includes: Execution of a Procedure
range includes: Execution Collection
range includes: Observation
range includes: Observation Collection
range includes: Sampling
range includes: Sampling Collection
implements: relatedObservation-sem
inverse of: has feature of interest
definition: relation from a FeatureOfInterest to an Execution, Execution Collection, or Deployment, operating on it i.e., to an Observation about it, to an Actuation acting on it, to an act of Sampling that sampled it, or to a Deployment for which it is the subject.

is hosted by
type: ObjectProperty
domain includes: Actuator
domain includes: Platform
domain includes: Sampler
domain includes: Sensor or Observer
domain includes: System
range includes: Platform
inverse of: hosts
definition: relation from an asset (System or Platform), to a Platform that it is mounted on or hosted by

is observed by
type: ObjectProperty
domain includes: Property
range includes: Sensor or Observer
implements: observer-sem
inverse of: observes
definition: relation from a Property to a Sensor that is able to observe it

is property of
type: ObjectProperty
domain includes: Property
range includes: Feature Of Interest
inverse of: has property
definition: relation from a Property to a FeatureOfInterest that it is a quality of

is subsystem of
type: ObjectProperty
domain includes: Actuator
domain includes: Sampler
domain includes: Sensor or Observer
domain includes: System
range includes: Actuator
range includes: Sampler
range includes: Sensor or Observer
range includes: System
inverse of: has subsystem
definition: relation from a component System to a System that it belongs to

made actuation
type: ObjectProperty
domain includes: Actuator
range includes: Actuation
range includes: Actuation Collection
sub property of: made execution
inverse of: made by actuator
definition: relation from an Actuator to an Actuation or ActuationCollection it has made

made observation
type: ObjectProperty
domain includes: Sensor or Observer
range includes: Observation
range includes: Observation Collection
implements: relatedObservation-sem
sub property of: made execution
inverse of: made by sensor or observer
definition: relation from a Sensor to an Observation or ObservationCollection it has made

observes
type: ObjectProperty
domain includes: Sensor or Observer
range includes: Property
implements: observableProperty-sem
sub property of: for property
inverse of: is observed by
definition: relation from a Sensor to a Property that it is capable of sensing

originated
type: ObjectProperty
domain includes: Stimulus
range includes: Observation
inverse of: was originated by
definition: relation from a Stimulus to an Observation that was originated by it

property for
type: ObjectProperty
domain includes: Property
range includes: Actuator
range includes: Procedure
range includes: Sensor or Observer
range includes: System
inverse of: for property
definition: relation from a Property to some Procedure or System that acts on it or observes it
example: For example, from a Sensor to the properties it can observe; from an Actuator to the properties it can act on; from a SystemCapability to the Property the capability is described for.

used for execution
type: ObjectProperty
domain includes: Procedure
range includes: Actuation
range includes: Execution of a Procedure
range includes: Observation
range includes: Sampling
implements: relatedObservation-sem
inverse of: used procedure
definition: relation from a Procedure to an Execution or ExecutionCollection made using it

was acted on by
type: ObjectProperty
domain includes: Property
range includes: Actuation
range includes: Actuation Collection
inverse of: acts on property
definition: relation from a Property to an Actuation that changed its state
example: In the activity (Actuation) of automatically closing a window if the temperature in a room drops below 20 degrees Celsius, the property upon which the Actuator acts is the state of the window as it changes from being open to being closed.

was observed by
type: ObjectProperty
domain includes: Property
range includes: Observation
range includes: Observation Collection
implements: relatedObservation-sem
inverse of: observed property
definition: relation from a Property to an Observation that observed it

was originated by
type: ObjectProperty
domain includes: Observation
domain includes: Observation Collection
range includes: Stimulus
inverse of: originated
definition: relation from an Observation to the Stimulus that originated it

acts on property
type: ObjectProperty
domain includes: Actuation
domain includes: Actuation Collection
range includes: Property
inverse of: was acted on by
definition: relation from an Actuation to the Property it acted upon
example: In the activity (Actuation) of automatically closing a window if the temperature in a room drops below 20 degrees Celsius, the property upon which the Actuator acts is the state of the window as it changes from being open to being closed.

has original sample
type: ObjectProperty
domain includes: Sample
domain includes: Sample Collection
range includes: Sample
inverse of: is original sample of
definition: relation from a Sample or SampleCollection to the initial Sample collected from the ultimate FeatureOfInterest

in deployment
type: ObjectProperty
domain includes: Platform
range includes: Deployment
implements: deployment-sem
sub property of: has deployment
inverse of: deployed on platform
definition: relation from a Platform to a Deployment
example: For example, a relation between a buoy and a deployment of several Sensors.

is proxy for
type: ObjectProperty
domain includes: Stimulus
range includes: Property
inverse of: has proxy
definition: relation from a Stimulus to the Property for which it is serving as a proxy
example: For example, the expansion of quicksilver is a stimulus that serves as a proxy for some temperature property. An increase or decrease in the velocity of spinning cups on a wind sensor is serving as a proxy for the wind speed.

is a result of made by sampler
type: ObjectProperty
domain includes: Sample
domain includes: Sample Collection
range includes: Sampler
inverse of: made sampling has result
property chain axiom: is result of
property chain axiom: made by sampler
definition: relation from a Sample or SampleCollection to the Sampler that made it

is a result of used procedure
type: ObjectProperty
domain includes: Sample
domain includes: Sample Collection
range includes: Sampling Procedure
inverse of: used for execution has result
property chain axiom: is result of
property chain axiom: used procedure
definition: relation from a Sample or SampleCollection to the Procedure (plan) used to make it

has sampled feature
type: ObjectProperty
domain includes: Sample
domain includes: Sample Collection
range includes: Feature Of Interest
implements: sampledFeature-sem
inverse of: feature has ultimate sample
definition: relation from a Sample or SampleCollection to the ultimate FeatureOfInterest that it is intended to be representative of; i.e., the end of a chain of isSampleOf relations

made by actuator
type: ObjectProperty
domain includes: Actuation
domain includes: Actuation Collection
range includes: Actuator
sub property of: made by system
inverse of: made actuation
definition: relation from an Actuation or ActuationCollection to the Actuator that made it

made by sensor or observer
type: ObjectProperty
domain includes: Observation
domain includes: Observation Collection
range includes: Sensor or Observer
implements: observer-sem
sub property of: made by system
inverse of: made observation
definition: relation from an Observation or ObservationCollection to the Sensor that made it

made sampling
type: ObjectProperty
domain includes: Sampler
range includes: Sampling
range includes: Sampling Collection
implements: sampling-sem
sub property of: made execution
inverse of: made by sampler
definition: relation from a Sampler to the Sampling or SamplingCollection it has made

observed property
type: ObjectProperty
domain includes: Observation
domain includes: Observation Collection
range includes: Property
implements: observedProperty-sem
inverse of: was observed by
definition: relation from an Observation or ObservationCollection to the property that was observed
note: 'observed property' covers the concepts referred to in [VIM] as 'measurand' (quantitative values) and 'examinand' (categorical and nominal values — [VIM4]), as well as complex and structured properties whose values may be represented as lists, vectors, arrays, rasters, geometries, etc. More specific terms are used in other contexts for related concepts, such as 'analyte' (chemistry) and 'determinand' (water quality).

SSN Ontology - core module
type: Ontology
created: 2024-02-03
creator: W3C/OGC Spatial Data on the Web Working Group
description: Core classes and properties for the SSN Ontology. This module adds RDFS and OWL axioms to the terms defined in SOSA Core
license: Software
license: copyright-software-and-document
rights: Copyright 2025 W3C/OGC.
imports: Sensor, Observation, Sample, and Actuator (SOSA) Ontology - core module

Operating Conditions
type: Class
definition: Type of observation or observation collection that describe operating conditions of systems. Sub-classes of this class explicit the desirability of the conditions. Three such sub-classes are provided as a basic classification: NormalOperatingConditions, SuboptimalOperatingConditions, and SurvivableConditions.

deployed asset
type: ObjectProperty
domain includes: Deployment
range includes: Actuator
range includes: Platform
range includes: Sampler
range includes: Sensor or Observer
range includes: System
inverse of: has deployment
definition: relation from a Deployment to an asset (System or Platform)

has deployment
type: ObjectProperty
domain includes: Actuator
domain includes: Platform
domain includes: Sampler
domain includes: Sensor or Observer
domain includes: System
range includes: Deployment
implements: deployment-sem
inverse of: deployed asset
definition: relation from a System or Platform to a Deployment in which it is deployed

is sample of
type: ObjectProperty
domain includes: Sample
domain includes: Sample Collection
range includes: Feature Of Interest
implements: sampledFeature-sem
inverse of: has sample
definition: relation from a Sample or SampleCollection to the FeatureOfInterest that it is intended to represent

made by sampler
type: ObjectProperty
domain includes: Sampling
domain includes: Sampling Collection
range includes: Sampler
implements: sampler-sem
sub property of: made by system
inverse of: made sampling
definition: relation from an act of Sampling to the Sampler that made it

Preparation Procedure
type: Class
implements: PreparationProcedure
subclass of: Restriction
  all values from: Preparation Step
  on property: implemented by
subclass of: Procedure
definition: [ISO 19156:2023] A PreparationProcedure shall be defined as the description of preparation steps performed on a Sample
definition: A workflow, protocol, plan, algorithm, or computational method specifying a step in preparing a Sample. A Preparation Procedure is re-usable, and might be involved in many preparations. It explains the steps to be carried out to arrive at reproducible results.

has result
type: FunctionalProperty
type: ObjectProperty
domain includes: Actuation
domain includes: Actuation Collection
domain includes: Execution of a Procedure
domain includes: Execution Collection
domain includes: Observation
domain includes: Observation Collection
domain includes: Sampling
domain includes: Sampling Collection
range includes: Sample
implements: result-sem
implements: sample-sem
inverse of: is result of
definition: relation from an Execution to its result In the case of an Actuation, the result may be the value of the Property following the execution of the Procedure by the Actuator. In the case of an Observation, the result is the value of the Property produced by the execution of the Procedure by the Sensor. In the case of a Sampling, the result is the Sample produced by the execution of the Procedure by the Sampler. An Execution has a single result, therefore sosa:hasResult is Functional.
note: The result value MUST be consistent with the hasOutput definition from the corresponding Procedure

has ultimate feature of interest
type: ObjectProperty
domain includes: Actuation
domain includes: Actuation Collection
domain includes: Deployment
domain includes: Execution of a Procedure
domain includes: Execution Collection
domain includes: Observation
domain includes: Observation Collection
domain includes: Sampling
domain includes: Sampling Collection
range includes: Feature Of Interest
implements: uFoI-sem
definition: relation from a Deployment or Execution to its ultimate subject entity i.e., from an Actuation to the ultimate entity whose property was modified; from an Observation to the ultimate entity whose property was observed; from an act of Sampling to the ultimate entity that was sampled; or from a Deployment to its ultimate target
note: should match a property chain something like this but with sosa:isSampleOf* owl:propertyChainAxiom ( sosa:hasFeatureOfInterest sosa:isSampleOf )
scope note: This is useful when the proximate feature of interest is a sample of the ultimate feature of interest, directly or transitively.

implements
type: ObjectProperty
domain includes: Actuator
domain includes: Sampler
domain includes: Sensor or Observer
domain includes: System
range includes: Actuating Procedure
range includes: Observing Procedure
range includes: Procedure
range includes: Sampling Procedure
implements: observingProcedure-sem
implements: samplingProcedure-sem
inverse of: implemented by
definition: relation from a System to the Procedure that it is capable of executing
example: For example, the relationship between a sensor and the scientific measuring Procedure via which it senses.

made execution
type: ObjectProperty
domain includes: System
range includes: Execution of a Procedure
range includes: Execution Collection
inverse of: made by system
definition: relation from a System to an Execution or ExecutionCollection that it has made
scope note: madeExecution generalizes the madeActuation, madeObservation, and madeSampling properties. It is included in the ontology to support the definition of a common pattern for executions and their properties. madeExecution MUST be considered to be abstract, so SHOULD NOT appear in data instances. Applications can use concrete sub-properties of madeExecution.

Actuating Procedure
type: Class
subclass of: Restriction
  all values from: Actuator
  on property: implemented by
subclass of: Procedure
definition: workflow, protocol, plan, algorithm, or computational method specifying how to make an Actuation An Actuating Procedure is re-usable, and might be applied in many Actuations. It explains the steps to be carried out to arrive at reproducible results.

Observing Procedure
type: Class
implements: ObservingProcedure
subclass of: Restriction
  all values from: Sensor or Observer
  on property: implemented by
subclass of: Procedure
definition: [ISO 19156:2023] An ObservingProcedure shall be defined as the description of steps performed in order to determine the value of an observableProperty by an Observer.
definition: workflow, protocol, plan, algorithm, or computational method specifying how to make an Observation An Observing Procedure is re-usable, and might be involved in many Observations. It explains the steps to be carried out to arrive at reproducible results.
example: A workflow, protocol, plan, algorithm, or computational method specifying how to make an observation; the description of the process used by an observer. This could be a chemical analysis method, a protocol for measuring an object, or even a checklist used by a human observer during a biodiversity campaign. The Procedure could further describe the algorithms behind simulators or models used to generate a result from other inputs.
example: [ISO 19156:2023] An instance of Procedure is a description of the process used by an observer. This could be a chemical analysis method, a protocol for measuring an object, or even a checklist used by a human observer during a biodiversity campaign. Procedure could further describe the algorithms behind simulators or models used to generate a result from other inputs.
note: [ISO 19156:2023] An ObservingProcedure shall be defined as the description of steps performed in order to determine the value of an observableProperty by an Observer.

for property
type: ObjectProperty
domain includes: Actuator
domain includes: Procedure
domain includes: Sensor or Observer
domain includes: System
range includes: Property
inverse of: property for
definition: relation from some Procedure or System to a Property it acts on or observes
example: For example, from a Sensor to the properties it can observe; from an Actuator to the properties it can act on; from a SystemCapability to the Property the capability is described for.

implemented by
type: ObjectProperty
domain includes: Procedure
range includes: Actuator
range includes: Sampler
range includes: Sensor or Observer
range includes: System
implements: observer-sem
implements: processingDetails-sem
implements: sampler-sem
inverse of: implements
definition: relation from a Procedure to a System that is capable of executing it
example: For example, the relationship between a scientific measuring Procedure and a sensor that senses via that Procedure.

is result of
type: ObjectProperty
domain includes: Sample
range includes: Actuation
range includes: Execution of a Procedure
range includes: Execution Collection
range includes: Observation
range includes: Sampling
implements: relatedObservation-sem
inverse of: has result
definition: relation from a result to the Execution that created or caused it

made by system
type: ObjectProperty
domain includes: Execution of a Procedure
domain includes: Execution Collection
range includes: System
inverse of: made execution
definition: relation from an Execution to the System that made it
scope note: madeBySystem generalizes the madeByActuator, madeBySensor, and madeBySampler properties. It is included in the ontology to support the definition of a common pattern for executions and their properties. madeBySystem MUST be considered to be abstract, so SHOULD NOT appear in data instances. Applications can use concrete sub-properties of madeBySystem.

Preparation Step
type: Class
implements: PreparationStep
subclass of: Restriction
  all values from: Preparation Procedure
  on property: used procedure
subclass of: Restriction
  cardinality: 1
  on property: preparedSample
subclass of: Restriction
  all values from: Sample
  on property: preparedSample
definition: A PreparationStep is an individual step pertaining to a Sample PreparationProcedure.
example: ???

has member of collection
type: ObjectProperty
domain includes: Actuation Collection
domain includes: Execution Collection
domain includes: Observation Collection
domain includes: Sample Collection
domain includes: Sampling Collection
range includes: Actuation
range includes: Actuation Collection
range includes: Execution of a Procedure
range includes: Execution Collection
range includes: Observation
range includes: Observation Collection
range includes: Sample
range includes: Sample Collection
range includes: Sampling
range includes: Sampling Collection
implements: member-sem
inverse of: is member of collection
definition: link from a Collection to an Execution or Sample or Collection of these that is part of it
editorial note: Note that there is a single `member` property. OWL or SHACL constraints may limit the range depending on the context of different collection types
scope note: rules for the consistency of values of properties of collections and properties of their members are given for each collection type

Ontology of operating conditions and capabilities of systems
type: Vocabulary
type: Ontology
created: 2017-05-14
creator: W3C/OGC Spatio-temporal Data on the Web Working Group
description: The System Capabilities Module imports SOSA and adds classes and properties required for the description of the operating conditions and capabilities of systems, particularly Sensors and Actuators.
license: Software
license: copyright-software-and-document
modified: 2025-06-24
rights: Copyright 2025 W3C/OGC.
preferred namespace prefix: sosa
preferred namespace uri: http://www.w3.org/ns/sosa/
comment: Please report any errors to the W3C Spatio-temporal Data on the Web Working Group via the SDW WG Public List public-sdw-wg@w3.org
imports: sosa

Stimulus
type: Class
subclass of: Restriction
  all values from: Class
    union of: Observation
    union of: Observation Collection
  on property: originated
subclass of: Restriction
  all values from: Sensor or Observer
  on property: is detected by
subclass of: Restriction
  all values from: Property
  on property: is proxy for
definition: event in the real world that triggers a Sensor
note: The properties associated to the Stimulus may be different to the eventual observed Property. It is the event, not the object, that triggers the Sensor.

Sampling Procedure
type: Class
implements: SamplingProcedure
subclass of: Restriction
  all values from: Sampler
  on property: implemented by
subclass of: Procedure
definition: [ISO 19156:2023] A SamplingProcedure shall be defined as the description of steps performed by a Sampler in order to extract a Sample from its sampledFeature in the frame of a Sampling.
definition: workflow, protocol, plan, algorithm, or computational method specifying how to make a Sampling A Sampling Procedure is re-usable, and might be involved in many Samplings. It explains the steps to be carried out to arrive at reproducible results.
example: spatial distribution of locations where to collect a sample (e.g., river segment) instrument (or mode of use thereof) required to collect a sample (e.g., fish net, electric stunner) field work instructions (e.g., dig four boreholes in each cardinal direction 2 metre way from the centre of the site; collect soil material from the 15-30 cm depth and mix it in a single bag)
note: [ISO 19156:2023] A SamplingProcedure shall be defined as the description of steps performed by a Sampler in order to extract a Sample from its sampledFeature in the frame of a Sampling.

has feature of interest
type: ObjectProperty
domain includes: Actuation
domain includes: Actuation Collection
domain includes: Deployment
domain includes: Execution of a Procedure
domain includes: Execution Collection
domain includes: Observation
domain includes: Observation Collection
domain includes: Sampling
domain includes: Sampling Collection
range includes: Feature Of Interest
implements: pFoI-sem
implements: featureOfInterest-sem
inverse of: is feature of interest of
definition: relation from an Execution or Deployment to its subject entity i.e., from an Actuation to the entity whose property was modified; from an Observation to the entity whose quality was observed; from an act of Sampling to the entity that was sampled; or from a Deployment to its target
example: For example, in an Observation of the weight of a person, the FeatureOfInterest is the person and the property is its weight.
scope note: This is the _proximate_ feature of interest, which may be a proxy entity such as a sample of the _ultimate_ feature of interest. Use `hasUltimateFeatureOfInterest` if the intention is to link to the _ultimate_ feature of interest.

Sensor, Observation, Sample, and Actuator (SOSA) Ontology - actuation module
type: Ontology
created: 2024-02-02
creator: W3C/OGC Spatial Data on the Web Working Group
description: Actuation classes and properties for the SSN Ontology.
license: Software
license: copyright-software-and-document
rights: Copyright 2025 W3C/OGC.
imports: Sensor, Observation, Sample, and Actuator (SOSA) Ontology - core module

used procedure
type: ObjectProperty
domain includes: Actuation
domain includes: Actuation Collection
domain includes: Execution of a Procedure
domain includes: Execution Collection
domain includes: Observation
domain includes: Observation Collection
domain includes: Sampling
domain includes: Sampling Collection
range includes: Actuating Procedure
range includes: Observing Procedure
range includes: Procedure
range includes: Sampling Procedure
implements: observingProcedure-sem
implements: samplingProcedure-sem
inverse of: used for execution
definition: relation from an Execution or ExecutionCollection to a Procedure used to make it

OMS Ontology - based on (SOSA) Ontology
type: Ontology
created: 2023-10-07
creator: W3C/OGC Spatial Data on the Web Working Group
description: This ontology is based on the SOSA Ontology by the W3C/OGC Spatial Data on the Web Working Group, supplemented by some classes and properties required to implement ISO 19156:2023 .
license: Software
license: copyright-software-and-document
rights: Copyright 2025 W3C/OGC.
source: 20-082r4.html
comment: The original source of each resource is indicated by the rdfs:isDefinedBy property
imports: Sensor, Observation, Sample, and Actuator (SOSA) Ontology - actuation module

Platform
type: Class
label: Platform or Host
source: ef
implements: Host
subclass of: Restriction
  all values from:
    union of: System
    union of: Platform
  on property: hosts
subclass of: Restriction
  all values from: Deployment
  on property: in deployment
alternative label: Host
definition: entity that hosts other entities, particularly Systems and other Platforms
example: A post, buoy, vehicle, ship, aircraft, satellite, cell-phone, human or animal may act as platforms for (technical or biological) sensors or actuators. An environmental monitoring facility. A platform that hosts a set of sensors. A team performing a survey, where each team member would be modeled as an Observer.
scope note: The INSPIRE 'Environmental Monitoring Facility' may be implemented using SOSA by the OWL/RDFS class 'Platform'

Deployment
type: Class
implements: Deployment
subclass of: Restriction
  all values from: Class
    union of: Platform
    union of: System
  on property: deployed asset
subclass of: Restriction
  all values from: Platform
  on property: deployed on platform
subclass of: Restriction
  all values from: System
  on property: deployed system
subclass of: Restriction
  all values from: Feature Of Interest
  on property: has feature of interest
definition: arrangement of one or more assets (Systems or Platforms) to execute Procedures with respect to designated features of interest.
example: A temperature Sensor deployed on a wall, a network of Sensors deployed for an Observation campaign.
note: A Deployment will usually be for a specified time interval. It MAY involve Platforms, or Systems, or both. A Deployment can be used quite flexibly to describe the use of systems, and platforms that host systems, with respect to a feature of interest.

Sample Collection
type: Class
implements: SampleCollection
subclass of: Restriction
  all values from:
    union of: Sample
    union of: Sample Collection
  on property: has member of collection
subclass of: Restriction
  all values from: Class
    union of: Sampling
    union of: Sampling Collection
  on property: is result of
subclass of: Restriction
  all values from: Feature Of Interest
  on property: is sample of
subclass of: Restriction
  all values from: Sample
  on property: has original sample
subclass of: Restriction
  all values from: Feature Of Interest
  on property: has sampled feature
subclass of: Restriction
  all values from: Sampler
  on property: is a result of made by sampler
subclass of: Restriction
  all values from: Sampling Procedure
  on property: is a result of used procedure
subclass of: Restriction
  all values from:
    union of: Sample
    union of: Sample Collection
  on property: has member of collection
definition: set of one or more Samples or SampleCollections; collections may be nested. All Sample properties may appear in a Sample Collection, including: hasOriginalSample , isSampleOfUltimateFOI , isSampleOf , isResultOfUsedProcedure , isResultOfMadeBySampler . If they are present, the value of these properties summarize the values of the matching properties of the member samples, where membership is either direct or transitive through one or more member sample collections. The following consistency rules apply with respect to the Sample properties listed above: 1. Where an individual Sample Collection omits a property, a member Sample (direct or transitive) MAY have any value for that property. 2. Where an individual Sample Collection has a single value for a property, each member Sample (direct or transitive) MUST have that same value for the property - i.e., the collection is homogeneous in that property. That property MAY be omitted in any member Sample or Sample Collection. 3. Where an individual Sample Collection has more than one value for a property, each member Sample (direct or transitive) MUST have a value for that property that matches one of the values for the property in the collection. 4. Where an individual Sample Collection has a value for a property that is a range or interval, each member Sample (direct or transitive) MUST have a value for that property that either matches or falls within that range or interval. 5. Where an individual Sample Collection has more than one value for a property that is a range or interval, each member Sample (direct or transitive) MUST have a value for that property that either matches or falls within one of those ranges or intervals.
note: The members of a collection do not necessarily share a common value for any property.

Procedure
type: Class
implements: Procedure
subclass of: Restriction
  all values from: System
  on property: implemented by
subclass of: Restriction
  all values from: Property
  on property: for property
definition: workflow, protocol, plan, algorithm, or computational method specifying how to make an Execution A Procedure is re-usable, and might be applied in many Actuations, Observations, or Samplings. It explains the steps to be carried out to arrive at reproducible results.
example: The measured wind speed differs depending on the height of the sensor above the surface, e.g., due to friction. Consequently, procedures for measuring wind speed define a standard height for anemometers above ground, typically 10m for meteorological measures and 2m in Agrometeorology. This definition of height, sensor placement, and so forth are defined by the Procedure.
scope note: Procedure generalizes the ActuationProcedure, ObservationProcedure, and SamplingProcedure classes. It is included in the ontology to support the definition of a common pattern for executions and their properties.

Sampling Collection
type: Class
subclass of: Restriction
  all values from: Sampler
  on property: made by sampler
subclass of: Restriction
  all values from: Sampling Procedure
  on property: used procedure
subclass of: Restriction
  all values from: Feature Of Interest
  on property: has feature of interest
subclass of: Restriction
  all values from: Sample
  on property: has result
subclass of: Restriction
  all values from:
    union of: Sampling
    union of: Sampling Collection
  on property: has member of collection
subclass of: Restriction
  all values from:
    union of: Sampling
    union of: Sampling Collection
  on property: has member of collection
subclass of: Execution Collection
definition: set of one or more Samplings or SamplingCollections; collections may be nested All Sampling properties may appear in a Sampling Collection, including: hasFeatureOfInterest , hasUltimateFeatureOfInterest , madeBySampler , usedProcedure , hasInputValue , startTime , phenomenonTime , resultTime , hasResult . If they are present, the value of these properties summarize the values of the matching properties of the member samplings, where membership is either direct or transitive through one or more member sampling collections. The following consistency rules apply with respect to the Sampling properties listed above: 1. Where an individual Sampling Collection omits a property, a member Sampling (direct or transitive) MAY have any value for that property. 2. Where an individual Sampling Collection has a single value for a property, each member Sampling (direct or transitive) MUST have that same value for the property - i.e., the collection is homogeneous in that property. That property MAY then be omitted in any member Sampling or Sampling Collection. 3. Where an individual Sampling Collection has more than one value for a property, each member Sampling (direct or transitive) MUST have a value for that property that matches one of the values for the property in the collection. 4. Where an individual Sampling Collection has a value for a property that is a range or interval, each member Sampling (direct or transitive) MUST have a value for that property that matches or falls within that range or interval. 5. Where an individual Sampling Collection has more than one value for a property that is a range or interval, each member Sampling (direct or transitive) MUST have a value for that property that either matches or falls within one of those ranges or intervals.
note: The members of a collection do not necessarily share a common value for any property.

Sampler
type: Class
implements: Sampler
subclass of: Restriction
  all values from: Sampling Procedure
  on property: implements
subclass of: Restriction
  all values from: Class
    union of: Sampling
    union of: Sampling Collection
  on property: made sampling
subclass of: System
definition: System that implements a SamplingProcedure to generate a Sample
example: A ball mill, diamond drill, hammer, hypodermic syringe and needle, image Sensor, or a soil auger can all act as Samplers. Sometimes, however, the distinction between the Sampler and the Sensor is not evident, if they are packaged as a unit.
note: A Sampler need not be a physical device.

Sensor, Observation, Sample, and Actuator (SOSA) Ontology - actuation module
type: Ontology
created: 2024-02-02
creator: W3C/OGC Spatial Data on the Web Working Group
description: Observation classes and properties for the SSN Ontology.
license: Software
license: copyright-software-and-document
rights: Copyright 2025 W3C/OGC.
imports: Sensor, Observation, Sample, and Actuator (SOSA) Ontology - core module

Sensor, Observation, Sample, and Actuator (SOSA) Ontology - actuation module
type: Ontology
created: 2024-02-02
creator: W3C/OGC Spatial Data on the Web Working Group
description: Sampling classes and properties for the SSN Ontology.
license: Software
license: copyright-software-and-document
rights: Copyright 2025 W3C/OGC.
imports: Sensor, Observation, Sample, and Actuator (SOSA) Ontology - core module

Actuation
type: Class
subclass of: Restriction
  all values from: Actuating Procedure
  on property: used procedure
subclass of: Restriction
  all values from: Feature Of Interest
  on property: has feature of interest
subclass of: Restriction
  all values from: Actuator
  on property: made by actuator
subclass of: Restriction
  all values from: Property
  on property: acts on property
subclass of: Execution of a Procedure
definition: act of carrying out an ActuatingProcedure using an Actuator to change the value of an actuatable Property of a FeatureOfInterest In this context hasResult may indicate the value of the Property at the completion of the Actuation
example: The activity of automatically closing a window if the temperature in a room drops below 20 degree Celsius. The activity is the Actuation and the device that closes the window is the Actuator. The Procedure is the rule, plan, or specification that defines the conditions that triggers the Actuation, here a drop in temperature.
note: relatedObservation SHOULD be used to link to an associated Observation or ObservationCollection that monitors the actuated property to verify that the result value has been obtained.
scope note: An Actuation primarily concerns a single Property of a single FeatureOfInterest. Changes to multiple properties, or other combinations of Actuations, may be described in an ActuationCollection. Alternatively, applications may choose to encapsulate complexity by defining a complex property with multiple individual components, and a corresponding complex result (e.g., a vector). This approach is not prohibited by the SSN Ontology, but the details are beyond the scope of SSN.

Actuation Collection
type: Class
subclass of: Restriction
  all values from: Actuator
  on property: made by actuator
subclass of: Restriction
  all values from: Property
  on property: acts on property
subclass of: Restriction
  all values from: Actuating Procedure
  on property: used procedure
subclass of: Restriction
  all values from: Feature Of Interest
  on property: has feature of interest
subclass of: Restriction
  all values from:
    union of: Actuation
    union of: Actuation Collection
  on property: has member of collection
subclass of: Execution Collection
definition: set of one or more Actuations or ActuationCollections; collections may be nested All Actuation properties may appear in an Actuation Collection, including: hasFeatureOfInterest , usedProcedure , madeByActuator , actsOnProperty , endTime , hasResult , hasSimpleResult . If they are present, the value of these properties summarize the values of the matching properties of the member actuations, where membership is either direct or transitive through one or more member actuation collections. The following consistency rules apply with respect to the Actuation properties: 1. Where an individual Actuation Collection omits a property, a member Actuation (direct or transitive) MAY have any value for that property. 2. Where an individual Actuation Collection has a single value for a property, each member Actuation (direct or transitive) MUST have that same value for the property - i.e., the collection is homogeneous in that property. That property MAY then be omitted in any member Actuation or Actuation Collection. 3. Where an individual Actuation Collection has more than one value for a property, each member Actuation (direct or transitive) MUST have a value for that property that matches one of the values for the property in the collection. 4. Where an individual Actuation Collection has a value for a property that is a range or interval, each member Actuation (direct or transitive) MUST have a value for that property that matches or falls within that range or interval. 5. Where an individual Actuation Collection has more than one value for a property that is a range or interval, each member Actuation (direct or transitive) MUST have a value for that property that either matches or falls within one of those ranges or intervals.
note: The members of a collection do not necessarily share a common value for any property.

Actuator
type: Class
subclass of: Restriction
  all values from: Property
  on property: acts on
subclass of: Restriction
  all values from: Actuating Procedure
  on property: implements
subclass of: Restriction
  all values from: Class
    union of: Actuation
    union of: Actuation Collection
  on property: made actuation
subclass of: System
definition: System that implements an ActuatingProcedure to change the value of an actuatable Property This may be a device, a piece of infrastructure, an agent (including humans), or software (simulation).
example: A window actuator for automatic window control, i.e., opening or closing the window.

Property
type: Class
implements: ObservableProperty
subclass of: Restriction
  all values from: Sensor or Observer
  on property: is observed by
subclass of: Restriction
  all values from:
    union of: Observation
    union of: Observation Collection
  on property: was observed by
subclass of: Restriction
  all values from: Stimulus
  on property:
    inverse of: is proxy for
subclass of: Restriction
  all values from: Actuator
  on property: is acted on by
subclass of: Restriction
  all values from:
    union of: Actuation
    union of: Actuation Collection
  on property: was acted on by
subclass of: Restriction
  all values from: Feature Of Interest
  on property: is property of
subclass of: Restriction
  all values from: Procedure
  on property: has procedure
definition: identifiable quality of features of interest that can be observed or acted upon A property can apply to different features of interest.
example: Cars (a feature type) all have a characteristic colour, where 'colour' is a property.
note: Concepts from existing code lists, vocabularies, and taxonomies, may be used as instances of Property

Sampling
type: Class
implements: Sampling
subclass of: Restriction
  all values from: Sampler
  on property: made by sampler
subclass of: Restriction
  all values from: Sampling Procedure
  on property: used procedure
subclass of: Restriction
  all values from: Feature Of Interest
  on property: has feature of interest
subclass of: Restriction
  all values from: Sample
  on property: has result
subclass of: Execution of a Procedure
definition: act of carrying out a SamplingProcedure using a Sampler to create one or more Samples of a FeatureOfInterest
example: Crushing a rock sample in a ball mill.
example: Digging a pit through a soil sequence.
example: Dividing a field site into quadrants.
example: Drawing blood from a patient.
example: Drilling an observation well.
example: Establishing a station for environmental monitoring.
example: Registering an image of the landscape.
example: Selecting a subset of a population.
example: Sieving a powder to separate the subset finer than 100-mesh.
example: Splitting a piece of drill-core to create two new samples.
example: Taking a diamond-drill core from a rock outcrop.

Sensor or Observer
type: Class
implements: Observer
subclass of: Restriction
  all values from: Stimulus
  on property: detects
subclass of: Restriction
  all values from: Property
  on property: observes
subclass of: Restriction
  all values from: Observing Procedure
  on property: implements
subclass of: Restriction
  all values from: Class
    union of: Observation
    union of: Observation Collection
  on property: made observation
subclass of: System
alternative label: Observer
definition: System that implements an ObservingProcedure to determine the value of an observable Property This may be a device, a piece of infrastructure, an agent (including humans), or software (simulation). A Sensor responds to a stimulus, e.g., a change in the environment, or input data composed from the results of prior Observations.
example: Accelerometers, gyroscopes, barometers, magnetometers, and so forth are Sensors that are typically mounted on a modern smartphone (which acts as Host or Platform). Other examples of Sensors include the human eyes.
note: The UML class 'Observer' from ISO 19156:2023 is implemented in SOSA by the OWL/RDFS class 'Sensor'. The class name 'Sensor' is preferred for backward compatibility with existing SOSA deployments.
preferred label: Sensor

Execution of a Procedure
type: Class
subclass of: Restriction
  all values from: System
  on property: made by system
subclass of: Restriction
  all values from: Procedure
  on property: used procedure
subclass of: Restriction
  on property: has feature of interest
  some values from: Feature Of Interest
subclass of: Restriction
  all values from: Feature Of Interest
  on property: has feature of interest
subclass of: Restriction
  all values from: Feature Of Interest
  on property: has ultimate feature of interest
definition: act of carrying out a Procedure using a System
scope note: Execution generalizes the Actuation, Observation, and Sampling classes. It is included in the ontology to support the definition of a common pattern for executions and their properties. Execution MUST be considered to be abstract, so any individual Execution SHOULD be declared to be an instance of one of the concrete sub-classes, and not of the Execution class.

Execution Collection
type: Class
subclass of: Restriction
  all values from: System
  on property: made by system
subclass of: Restriction
  all values from: Procedure
  on property: used procedure
subclass of: Restriction
  all values from: Feature Of Interest
  on property: has feature of interest
subclass of: Restriction
  all values from: Feature Of Interest
  on property: has ultimate feature of interest
subclass of: Restriction
  all values from:
    union of: Execution of a Procedure
    union of: Execution Collection
  on property: has member of collection
definition: set of one or more Executions or ExecutionCollections; collections may be nested All Execution properties may appear in an Execution Collection, including: hasFeatureOfInterest , usedProcedure , madeBySystem , endTime, resultTime , startTime . If they are present, the value of these properties summarize the values of the matching properties of the member Executions, where membership is either direct or transitive through one or more member execution collections. The following consistency rules apply with respect to the execution properties listed above: 1. Where an individual Execution Collection omits a property, a member Execution (direct or transitive) MAY have any value for that property. 2. Where an individual Execution Collection has a single value for a property, each member Execution (direct or transitive) MUST have that same value for the property - i.e., the collection is homogeneous in that property. That property MAY then be omitted in any member Execution or Execution Collection. 3. Where an individual Execution Collection has more than one value for a property, each member Execution (direct or transitive) MUST have a value for that property that matches one of the values for the property in the collection. 4. Where an individual Execution Collection has a value for a property that is a range or interval, each member Execution (direct or transitive) MUST have a value for that property that matches or falls within that range or interval. 5. Where an individual Execution Collection has more than one value for a property that is a range or interval, each member Execution (direct or transitive) MUST have a value for that property that either matches or falls within one of those ranges or intervals.
note: The members of a collection do not necessarily share a common value for any property.
scope note: Execution Collection generalizes the Actuation Collection, Observation Collection, and Sampling Collection classes. It is included in the ontology to support the definition of a common pattern for executions and their properties. Execution Collection MUST be considered to be abstract, so any individual Execution Collection SHOULD be declared to be an instance of one of the concrete sub-classes, and not of the Execution Collection class.

Feature Of Interest
type: Class
subclass of: Restriction
  on property: is feature of interest of
  some values from: Class
    union of: Deployment
    union of: Execution of a Procedure
    union of: Execution Collection
subclass of: Restriction
  all values from: Property
  on property: has property
subclass of: Restriction
  all values from: Sample
  on property: has sample
definition: entity that is the target of an Execution or Deployment i.e., whose property is being estimated by an Observation, or whose property is being manipulated by an Actuator, or which is being sampled or transformed in an act of Sampling, or which is the target of Executions planned as part of a Deployment.
example: When measuring the height of a tree, the height is the observed Property, 20m may be the Result of the Observation, and the tree is the FeatureOfInterest. A window is a FeatureOfInterest for an automatic window control Actuation.

System
type: Class
subclass of: Restriction
  all values from: Platform
  on property: is hosted by
subclass of: Restriction
  all values from: Procedure
  on property: implements
subclass of: Restriction
  all values from: Property
  on property: for property
subclass of: Restriction
  all values from: System
  on property: has subsystem
subclass of: Restriction
  all values from: System
  on property: is subsystem of
subclass of: Restriction
  all values from: Deployment
  on property: has deployment
subclass of: Restriction
  all values from: Class
    union of: Execution of a Procedure
    union of: Execution Collection
  on property: made execution
definition: entity that implements a Procedure in the context of an Execution
note: This may be a device, a piece of infrastructure, an agent (including humans), or software (simulation). Different Systems can implement the same (reusable) Procedure for different Executions. A System may have components, its sub-systems, which are other systems.
scope note: Specific system types may be implemented as sub-classes of this class or its sub-classes. Their descriptions may capture the properties and characteristics of a whole class of systems, corresponding with the information typically found in a data-sheet. Individual system instances are members of this class or its sub-classes.
scope note: System generalizes the Actuator, Sensor, and Sampler classes. It is included in the ontology to support the definition of a common pattern for executions and their properties. System MUST be considered to be abstract, so any individual System SHOULD be declared to be an instance of a concrete sub-class, and not of the System class.
scope note: The association of a System (Actuator, Sensor, and Sampler) with a FeatureOfInterest is usually in the context of an Execution or a Deployment. A System can be hosted by a Platform. A System can be deployed for a specified time interval as part of a Deployment.

Sample
type: Class
implements: Sample
subclass of: Restriction
  all values from: Preparation Step
  on property: has preparation step
subclass of: Restriction
  all values from: Sampler
  on property: is a result of made by sampler
subclass of: Restriction
  all values from: Sampling Procedure
  on property: is a result of used procedure
subclass of: Restriction
  all values from: Class
    union of: Sampling
    union of: Sampling Collection
  on property: is result of
subclass of: Restriction
  all values from: Feature Of Interest
  on property: is sample of
subclass of: Restriction
  min cardinality: 1
  on property: is sample of
subclass of: Restriction
  all values from: Sample
  on property: has original sample
subclass of: Restriction
  all values from: Feature Of Interest
  on property: has sampled feature
definition: piece or subset that is intended to be representative of a FeatureOfInterest
example: A 'station' is a spatial sample, in the form of an identifiable locality where a sensor system or Procedure may be deployed and an observation made. In the context of the observation model, it connotes the 'world in the vicinity of the station', so the observed properties relate to the physical medium at the station, and not to any physical artifact such as a mooring, buoy, benchmark, monument, well, etc.
example: A statistical sample is often designed to be characteristic of an entire population, so that observations can be made regarding the sample that provide a good estimate of the properties of the population.
note: Samples are typically subsets or extracts from an entity or feature. Every sample is expected to (eventually) be the feature of interest of an Observation. Samples are used in situations where observations cannot be made directly on the ultimate feature of interest, either because the entire feature cannot be observed, or because it is more convenient to use a proxy. Samples are thus artifacts of an observational strategy, and have no significant function outside of their role in the observation process. The characteristics of the samples themselves are of little interest, except perhaps to the manager of a sampling campaign. A Sample is intended to sample some FatureOfInterest, so there is an expectation of at least one isSampleOf property. However, in some cases the identity, and even the exact type, of the sampled feature may not be known when observations are made using the sample. Physical samples are sometimes known as 'specimens'. A transient sample, such as a ships-track or flight-line, might be identified and described, but is unlikely to be revisited exactly.

Observation Collection
type: Class
implements: ObservationCollection
subclass of: Restriction
  all values from: Feature Of Interest
  on property: has ultimate feature of interest
subclass of: Restriction
  all values from: Sensor or Observer
  on property: made by sensor or observer
subclass of: Restriction
  all values from: Property
  on property: observed property
subclass of: Restriction
  all values from: Observing Procedure
  on property: used procedure
subclass of: Restriction
  all values from:
    union of: Observation
    union of: Observation Collection
  on property: has member of collection
subclass of: Execution Collection
definition: set of one or more Observations or ObservationCollections; collections may be nested All Observation properties may appear in an Observation Collection, including: hasFeatureOfInterest , hasUltimateFeatureOfInterest , usedProcedure , madeBySensor , observedProperty , phenomenonTime , startTime, resultTime , hasResult , hasSimpleResult : If they are present, the value of these properties summarize the values of the matching properties of the member observations, where membership is either direct or transitive through one or more member observation collections. The following consistency rules apply with respect to the Observation properties listed above: 1. Where an individual Observation Collection omits a property, a member Observation (direct or transitive) MAY have any value for that property. 2. Where an individual Observation Collection has a single value for a property, each member Observation(direct or transitive) MUST have that same value for the property - i.e., the collection is homogeneous in that property. That property MAY then be omitted in any member Observation or Observation Collection. 3. Where an individual Observation Collection has more than one value for a property, each member Observation (direct or transitive) MUST have a value for that property that matches one of the values for the property in the collection. 4. Where an individual Observation Collection has a value for a property that is a range or interval, each member Observation (direct or transitive) MUST have a value for that property that matches or falls within that range or interval. 5. Where an individual Observation Collection has more than one value for a property that is a range or interval, each member Observation (direct or transitive) MUST have a value for that property that either matches or falls within one of those ranges or intervals.
note: The results of collections of observations are often packaged in a 'data cube' whose axes define the range of properties of the set of observations.
note: An instance of ObservationCollection represents a container for a set of data derived from observations. This broadly corresponds with the class Dataset from DCAT.
note: The members of a collection do not necessarily share a common value for any property.

Observation
type: Class
implements: Observation
subclass of: Restriction
  all values from: Observing Procedure
  on property: used procedure
subclass of: Restriction
  all values from: Feature Of Interest
  on property: has feature of interest
subclass of: Restriction
  all values from: Feature Of Interest
  on property: has ultimate feature of interest
subclass of: Restriction
  all values from: Property
  on property: observed property
subclass of: Restriction
  all values from: Stimulus
  on property: was originated by
subclass of: Restriction
  all values from: Sensor or Observer
  on property: made by sensor or observer
subclass of: Execution of a Procedure
definition: act of carrying out an ObservingProcedure using a Sensor to estimate or calculate a value of an observable Property of a FeatureOfInterest
example: The activity of estimating the intensity of an Earthquake using the Mercalli intensity scale is an Observation as is measuring the moment magnitude, i.e., the energy released by said earthquake.
note: When the feature of interest cannot be observed directly, a sample of it might be used in Observations as a proxy for it. In such case, the Sample is the proximate Feature of Interest of the Observation, while the (ultimate) Feature of Interest of the act of Sampling (i.e., the entity that the Sample is ultimately 'isSampleOf') is the ultimate Feature of Interest of the Observation.
scope note: An Observation primarily concerns a single Property of a single FeatureOfInterest. Observations of multiple properties, or other combinations of Observations, may be described in an ObservationCollection. Alternatively, applications may choose to encapsulate complexity by defining a complex property with multiple individual components, and a corresponding complex result (e.g., a vector). This approach is not prohibited by the SSN Ontology, but the details are beyond the scope of SSN.

Sensor, Observation, Sample, and Actuator (SOSA) Ontology - core module
type: Ontology
created: 2024-02-02
creator: W3C/OGC Spatial Data on the Web Working Group
description: Core classes and properties for the SSN Ontology.
license: Software
license: copyright-software-and-document
rights: Copyright 2025 W3C/OGC.