The figure below shows the main AIXM 5 classes used for the navaid concept.
...
In AIXM 5, a Navaid is composed of one or more NavaidEquipment.
...
| title | Open Question |
|---|
NavaidEquipment
...
.
...
To describe a physical navaid equipment in AIXM 5, the NavaidEquipment class is used. This class is specialised into: Azimuth, DME, DirectionFinder, Elevation, Glidepath, Localizer, MarkerBeacon, NDB, SDF, TACAN, VOR.
...
In addition, also related to Navaid class are the servedAirport if any, and the availability of the Navaid defined by one or more Timesheet (see Schedule [TSH] Common coding patterns for details).
A Navaid may be used a SignificantPoint, e.g. for the start or end point of a route or terminal procedure or the centre point of a TAA/MSA, etc.
Each NavaidEquipment will have a location defined by the Point class. For certain NavaidEquipment an elevation has to be defined. In this case, the ElevatedPoint class has to be used (e.g. for DME).
This location of each of the NavaidEquipment of a Navaid may be the same (e.g. for a VOR/DME or a NDB collocated with a MarkerDME), or different (e.g. for a VOR/DME or the components of an ILS).
Also, the Navaid class itself may have a location. This is the location used when the navaid acts as a significant point (see also SignificantPoint [SPN](Overview)). This location is usually the location of one of the navaid equipments (e.g. in case of a VOR/DME it will be in general the location of the VOR).
...
Only the VOR has also a zeroBearingDirection, a code indicating the direction of the 'zero bearing' provided by the station. For example: magnetic north, true north.
The Navaid class is also used to code landing systems (e.g. ILS, Localizer only, MLS). It will be comopsed of the corresponding instances of NavaidEquipment, e.g. Localizer, Glidepath, MarkerBeacon, DME, etc.). Finally, the Navaid and not its individual components isInstalledAt a RunwayDirection.
A NavaidEquipment isUnderResponsibilityOf an OrganisationAuthority.