The following diagram shows the AIXM 5.1(.1) classes that model the concept of Obstacle Areas:
The ObstacleArea class is the main element, with an attribute named type that can be used for the identification of the area: 'AREA1', 'AREA2', 'AREA3', etc.
The list of values is likely to be modified in AIXM 5.2, in order to reflect the latest ICAO subdivision of the Area 2 (a, b, c, d), which is missing from the current model. Also, the attribute obstructionIdSurfaceCondition is likely to be revisited in AIXM 5.2.
Each ObstacleArea may be associated with one of the following:
- an AirportHeliport - for areas that are defined in relation with an airport, such as the Area 2
- a RunwayDirection - for areas that are defined in relation with a particular runway landing and take-off direction
- an OrganisationAuthority - for areas that are defined in relation with the whole State territory
The horizontal projection of the ObstacleArea is modelled through the association hasExtent with Surface.
Finally, the model allows to associate the ObstacleArea with zero or more VerticalStructure, which allows to directly identify the obstacles declared as being situated in each obstacle area. This means not only that the obstacle is situated within the geographical limits of the area, but also that it satisfies the data collection rules for obstacles in that area.