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The term significant point is not defined In ANNEX 15 nor in PANS-AIM. However, the term "significant point" and also also "designated significant point" is sued in used in PANS-AIM several times,
especially in "ENR 3. ATS ROUTES".
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In AIXM, the SignificantPoint class could be seen as a 'placeholder' for a Navaid, Runway Point (e.g. a Threshold Position), Airport Reference Point, Aiming Point of a TLOF, Designated Point or a simple Point in space. At a conceptual level, it simplifies the model by significantly reducing the number of relationships. See also topic SignificantPoint [SPN].
Designated Point
A term that is only defined by AIXM. The 'Designated Point' definition is derived from the Significant Point definition, by difference:
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