SensorML 2.0 Examples

In order to support a wide variety of needs for providing location, orientation, and dynamic state of a physical component or system, there are several means for specifying "where". These include byDescription, byPoint, byLocation, byState, byTrajectory, and byProcess.

For a static location where orientation is important, one must use a swe:DataRecord which has at two fields. One field being a swe:Vector providing a 3D location and the second field being a swe:Vector providing orientation. The two swe:Vector elements allow one to specify the location and orientation relative to a geospatial reference frame (e.g. CRS 4979) or relative to the spatial reference frame of another physical component (e.g. the platform).

While including a definition of the component's local reference frame is recommended for all physical components, it is required for defining orientation or dynamic state of a component. The local reference frame provides in a textual description the location and orientation of the local reference axes of the component itself [see highlighted localReferenceFrame description]. Then the location of the component relative to the outside world is the location of the origin of its local reference frame to some geospatial reference system or the reference frame of some other component. Likewise, the orientation of the component is the relationship of the component's local reference axes to the correspnding axes of the external reference frame.

In this example, the location is expressed relative to the CRS4979 reference frame (which is latitude, logitude, and altitude based on the WGS84 datum) while the orientation is expressed as true heading, pitch, and roll relative to the North-East-Down (NED) reference frame.