Page Comparison

It seems that these three terms are not consistantly used throughout the avaition domain.

Designated Point:

A term that is only used by AIXM: It defines a Designated Point as follows:

A  geographical location not marked by the site of a radio navigation aid, used in defining an ATS route, the flight path of an aircraft or for other navigation or ATS purposes.

In AIXM a DesigantedPoint is a specialisation of a SignificantPoint.

Sigificant Point:

In AIXM a SignificantPoint is defined as follows:

A link class that allows selecting between a navaid system, a runway point, an airport reference point, an aiming point or a fix designated point.

SignificantPoint accounts for a specified geographical location used to define an ATS route, the flight path of an aircraft or for other navigation/ATS purposes.

In other words a Significant Point in AIXM comprises all kind of point locations such as Designated Point, Navaid, Airport Reference Point, Runway Threshold position, a simple Point in space, etc.

Annex 11 Defines Significant point as follows

A specified geographical location used in defining an ATS route or the flight path of an aircraft and for other navigation and ATS purposes.

Note.— There are three categories of significant points: ground-based navigation aid, intersection and waypoint. In the context of this definition, intersection is a significant point expressed as radials, bearings and/or distances from groundbasednavigation aids.

The term significant point is not defined In ANNEX 15 or PANS-AIM. However, the terms significant point and desiganted significant points occurs in several sections, especially in "ENR 3. ATS ROUTES" to define the route.

...coded designators or name-codes and the geographical coordinates ... of all significant points defining the route

Section "ENR 4.4 Name-code designators for significant points" provides is used to publish a list of

...name-code designators (five-letter pronounceable “name-code”) established for significant points at positions not marked by the site of radio navigation aids

Waypoint:

The term waypoint is not used in AIXM but in ICAO documents:

ICAO Annex 11 defines waypoint exclusivly in the scope of RNAV operations

A specified geographical location used to define an area navigation route or the flight path of an aircraft employing area navigation.

In this regard it distinguishes between Fly-by waypoint and Flyover waypoint.

Annex 11 defines waypoint as a kind of significant point (see definition above).

Also in ICAO Annex 15 and PANS-AIM the term waypoint is used in the RNAV context. Sections "ENR 3.3 Area navigation routes" states

in respect of waypoints defining an area navigation route, additionally as applicable:

a) station identification of the reference VOR/DME;

The term is also used in "ENR 3.6 En-route holding" without a particular reference to RNAV.

The requirement is for a detailed description of en-route holding procedures, containing:

1) holding identification (if any) and holding fix (navigation aid) or waypoint

Also PANS-AIMS includes the "Waypoint – en-route" subject as part the AIP data set without pointing to any RNAV context.

In Appendix 1 of PANS-OPS (Aeronautical Data Catalogue) the Waypoint subject is part of the ATS Route section, presuming that the term is applicable for all kind of ATS routes and not only RNAV routes!