This example shows how AIP information about the geometry of an airspace (TMA AQUITAINE part 2-1) is used to calculate the AIXM/GML digital representation of the horizontal projection of that Airspace.
Information published in AIP France ENR 2.3
| Screenshot of map showing the horizontal extent of the TMA
|
|---|
The horizontal projection of the airspace starts with a "clockwise arc". The center is 44°49'37"N; 000°43'16"W. The first point is A (45°07'24"N; 001°03'41"W) and the second point is B (44°47'02"N; 000°11'15"W). The radius is declared as 23 NM.
...
- distance from center to point A: 22.942 NM (0.25% difference to 23 NM)
- distance from center to point B: 22.941 NM (0.26% difference to 23 NM)
Therefore, the official AIP value of 23 NM may be safely used in the GML encoding. If the difference was higher than 1%, the data originator should be contacted in order to provide a more accurate value for the arc radius.
The resulting GML ArcByCenterPoint can be encoded as follows:
To be added