ObservedProperty

ObservedProperty is a defined physical quantity or phenomenon that is observed or measured by sensors or sensor networks. In standards such as the Sensor Web Enablement (SWE) framework and related data models, an ObservedProperty identifies what is being observed, for example temperature, air pressure, salinity, wind speed, or soil moisture. Each observed property typically has a human-readable name and a formal definition, often expressed as a Uniform Resource Identifier (URI) that links to a vocabulary or ontology. This formalization supports consistent interpretation of sensor outputs across devices, services, and data collections.

ObservedProperty can be associated with a Unit of Measure to indicate the scale or units used for the observation, although some specifications treat units as a separate concern. In practice, ObservedProperty is used to characterize observations in data models and services such as the Sensor Observation Service (SOS) and SensorML, where it appears as a property of observations and aids in describing what the result represents.

In the Semantic Sensor Network (SSN) ontology, ObservedProperty is a class representing the property of interest measured by a sensor, with connections to units and to definitional URIs. Examples include a property like temperature defined by a specific URI or a property such as water depth defined within an ontology.

See also: Sensor Web Enablement, SOS, SensorML, SSN ontology, Unit of Measure, Phenomenon, Definition.