ssn:System
The ssn:System class is used in SDL to represent a physical or logical configuration of instruments or components capable of making observations.
Definition
URI: http://www.w3.org/ns/ssn/System
A ssn:System is a unit of deployment or instrumentation that can contain subsystems, sensors, and actuators. It may be a standalone device, a software-based sensing pipeline, or a composed platform.
Usage in SDL
In SDL, ssn:System is typically used to:
- Represent a complete sensor platform (e.g. a LI-COR 8250 configured system)
- Group physical components or subsystems
- Serve as the target of a ssn:Deployment
- Link observations to system context
It is usually composed with other types, e.g.:
ex:licor8250Config1 a ssn:System , sosa:Sensor ;
dct:title "LI-COR 8250 with headspace manifold" ;
ssn:hasSubSystem ex:li8250 , ex:li8250_headspace ;
sosa:observes ex:co2 , ex:ch4 .
Related Properties
| Property | Description |
|---|---|
| ssn:hasSubSystem | Indicates constituent components or subsystems |
| ssn:deployedSystem | Used by ssn:Deployment to link to this system |
| sosa:observes | The observable properties measured by the system |
| dcterms:title | A human-readable name or label |
Composition
ssn:System is frequently used together with:
- sosa:Sensor — when the system is actively making measurements
- prov:Entity — when tracking provenance of measurements generated by the system
- dcat:Resource — when cataloging systems in a registry
Container Pattern
Systems are stored in SDL under a platform-service endpoint using a BasicContainer, allowing manual management of subsystem members.
Example
ex:platform1 a ssn:System , sosa:Sensor ;
dct:title "Soil Gas Sensor Rig" ;
ssn:hasSubSystem ex:li8250 , ex:li8250_manifold ;
sosa:observes ex:co2 , ex:ch4 ;
dct:identifier "rig-2023-soilgas" .
See Also
- ssn:Deployment
- sosa:Sensor
[SDL Platform Service Documentation](./services/platform.md)
The ssn:System is central to modeling instrumentation and sensor configurations in SDL and acts as a reusable reference across deployments, observations, and metadata registries.