Positions of navaids or designated points may be used in the aeronautical information domain in order to define the shape of an airspace. They can be used as arc centers or even as boundary points.
The UML model of AIXM shows a “dependency” association between Surface and SignificantPoint in order to cater for such situations.
For the detailed AIXM/GML encoding see the document Guidance and Profile of GML for use with Aviation Data.
Coding Examples
More examples to be defined in the sope of the DONLON AIP data set.