How to model your sensor metadata in SOS 2.0?

SOS 2.0 recommends to encode sensor metadata in SensorML. The components of SensorML and how they can be used in applications is described in detail on the SensorML network site and the information resources which are linked there.

In summary, the SensorML standard specifies a model and encoding for sensor related processes such as measuring or post processing procedures. Physical as well as logical sensors are modeled as processes. The functional model of a process can be described in detail, including its identification, classification, inputs, outputs, parameters, and characteristics such as a spatial or temporal description. Processes can be composed by process chains.

A System is a subtype of process and used to describe physical sensors. The figure below shows the main elements of a SensorML document to describe a sensor system. The sub-components of the sensor system (e.g. a weather station) are listed in the components element at the bottom.

Neither the SOS specification nor the SensorML specification prescribes which of the many SensorML metadata elements have to be provided by an SOS server. However, in order to reach a certain level of interoperability we recommend to use profiles such as the SensorML Profile for Sensor Discovery (OGC 09-033).