FeatureOfInterest

FeatureOfInterest (FoI) is a concept in open geospatial standards describing the real-world object or place whose properties are observed by sensors and reported in sensor observations. An FoI provides the spatial context for an observation: each observation in a sensor data model is associated with a feature of interest, allowing the data to be linked to a specific place, object, or region rather than to the sensor alone.

FoIs can be points, lines, polygons, or more complex geometries and may represent geographic features such as a lake, a building, a watershed, a moving object, or an area of interest. Each FoI is identified by an identifier and may be described by a geometry in standard formats (such as GML or WKT) and by metadata such as name, type, or links to a feature catalog.

In practice, the FoI links observations to a real-world feature; the ObservedProperty describes what is measured (for example, temperature or pollutant concentration), the Procedure identifies the sensor or process, and the FoI identifies where the measurement applies. This separation supports data integration and enables spatial queries, such as filtering observations by location or aggregating results by feature.

FoIs can be stationary or dynamic. For moving objects, the FoI may be updated over time or represented with time-stamped geometries. Standards also support linking FoIs to external feature catalogs or services, facilitating broader data interoperability.

Examples include a weather station's observation linked to the station's location, river water quality observations associated with a river segment, or wildlife tracking data tied to an individual animal's movements.