Micrsoft SenseWeb research experiments with an OWL ontology
SenseWeb is a Microsoft research project that attempts to bring real-time sensor data onto the Web. SenseWeb web portal allows users to visualize and query live sensor data in a digital map interface (Windows Live Local), and allows data owners to publish data using a web service interface.
VerySpatial blog has some discussion about this service, highlighting its current implementation strength and shortcomings. A live demo of the service can be found on the SensorMap website.
An important part of the SenseWeb portal design is the modeling of physical sensors, describing different classes of sensors and their respective properties. Interestingly, SenseWeb defines this model using the Web Ontology Language OWL.