...
The GeoBorder class is used for a physical or political border. In general, it will be the border between two countries or States states but could also be a coastline, the description of the bank of an important river, or any other geographical shape which can be named and used to describe the border of an airspace. If two countries/States states have more than one common border, each one will be an occurrence of this entity.
...
The UML model of AIXM shows a “dependency” association between Surface and GeoBorder to cater for such situations.
The encoding is possible in two ways: either with a simple annotation (and copy of all necessary points) or by reference.
For the detailed AIXM/GML encoding, see the document Guidance and Profile of GML for use with Aviation Data.
...
More examples TBD in the scope of the DONLON AIXM AIP data set.