AIXM 5.1.1 Application Schema and Extensions
AIXM was developed to be extensible, allowing greater flexibility for international use, in particular to meet individual needs of the AIXM Community of Interest (COI).
The Extension Class concept supports the following:
- extending the core AIXM classes (features and objects) with new attributes or associations;
- defining new aeronautical information features, which are only relevant for that community.
The Extension Message concept supports the definition of message types that are exchanged in that community. Such messages may have additional properties and might eventually restricting their content to a subset of the AIXM features. They can also include additional feature properties and new features defined through an extension. However, it is not obligatory that specific AIXM messages are defined. Data exchange can be instantiated through standard "feature services". An example is the OGC Web Feature Service (WFS), which enables the direct provision of individual AIXM features or collections of AIXM features. The AIXM core model also provides a "Basic Message", which is simply a collection of any AIXM features. It can be used with both core AIXM features and extensions.
More information is are available here: https://ext.eurocontrol.int/aixm_confluence/display/AC/Extensions