ID: | AIXM-555 |
target version: | AIXM 5.2 |
version: | 1.0 |
last updated: | 08 AUG 2022 |
status: | APPROVED |
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Description
The DesignatedPoint.type list of values is updated. Values MTR and DESIGNED are removed, a new value for VRP (visual reference point) is added and some existing values definitions are updated.
Rationale for change
See https://aixmccb.atlassian.net/browse/AIXM-394
The type attribute of the DesignatedPoint is defined as “The kind of point designator, indicating the rules by which the designator has been created”. This attribute is not meant to indicate how the point is used, for example if it is used for VFR. However, there might be an implicit relation between the rules by which the point designator was created and the intended use of the point. For example, a point with an ICAO type designator is primarily intended for IFR routes and is used in ATC verbal communication.
The current list of values includes some entries that are not in line with the attribute definition and are therefore proposed to be removed:
- DESIGNED = "A point with bearing/distance designator used as control point for procedure design, which is not published." The problem is that the definition says that this is a bearing/distance, therefore BRG_DIST type may be used instead;
- MTR = "point used on a military training route" - not specified what rules apply for the designator of such points and it is mostly about the intended use, not the designator type.
The CNF value is defined as "Computer Navigation Fix". According to the FAA order 8260.19I, this is used as aid in computer navigation in some particular cases: Non-RNAV MAP not at LTP, RF centre, some en-route dog leg change-over points. The designator starts with “CF” followed by three consonants. The current definition is not sufficiently precise, it should include the FAA reference.
The TERMINAL value is defined as “Point with a five-alphanumeric name-code, used as waypoint in RNAV procedures and which does not have a globally unique ICAO 5-letter designator”. However, such points are also specified on non-RNAV procedures and may have less than 5 characters. Thus, the definition should be updated.
The current list of values is missing a type for visual reference points, which are typically defined with reference to an identifiable location on the ground and are used for VFR navigation. The designator of such points is either defined from the name of a ground location or by applying a local naming convention. For example:
- designator = VP001, annotation = “A1(M) JUNCTION 4”
- designator = PESW2, annotation = “A point SW of LIPE aerodrome, further away than PESW1”
Impact assessment
When receiving data from AIXM 5.1(.1) implementations, AIXM 5.2 systems will have to be able to map forward the removed values as described in the mapping rules further in this document.
When receiving data from AIXM 5.2 implementations, current AIXM 5.1(.1) systems will have to be able to map back the new values as described in the mapping rules further in this document.
Copied from the CP...
Mapping AIXM 5.1.1 to AIXM 5.2 (forward)
[MAPC-01] The following algorithm shall be applied:
- For each DesignatedPoint that has type equal-to one of the following values:
- ‘DESIGNED’ - replace with ‘OTHER:DESIGNED’
- ‘MTR’ - replace with ‘OTHER:MTR’
- ‘OTHER:VRP’ - replace with ‘VRP’
Mapping AIXM 5.2 to AIXM 5.1.1 (backward)
[MAPC-01] The following algorithm shall be applied:
- For each DesignatedPoint that has type equal-to one of the following values:
- ‘VRP’ - replace with ‘OTHER:VRP’
Mapping example
(Note: for mapping test data see: https://github.com/aixm/mapping_52_511/tree/master/AIXM-xxx)
AIXM 5.2 | AIXM 5.1(.1) | ||||
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