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[AIXM-525] Add magnetic variation information to Procedures

[AIXM-525] Add magnetic variation information to Procedures

Owned by georgiana.andrei04
Last updated: 2024 Aug 19 by ADAM STYLES

ID:

AIXM-525

target version:

AIXM 5.2

version:

1.0

last updated:

08 AUG 2022

status:

APPROVED


Description

Attributes for magneticVariation and dateMagneticVariation are added to the Procedure class.

Rationale for change

See https://aixmccb.atlassian.net/browse/AIXM-469

It was identified and supported by worldwide AIP examples that magnetic variation values and date of magvar measurement may differ from the information available for the AirportHeliport itself. This addition would also allow for alignment with ARINC 424 PDMV coding field and ICAO PANS-AIM Aeronautical Data Catalogue.

Impact assessment

[FWD_1:1] No data mapping is necessary and no data loss occurs when data is exchanged from a system (A) that uses AIXM 5.1.1 for output towards a system (B) that uses AIXM 5.2 for input.

[BWD_MAP_LOSS] Data mapping is possible, but some data would be lost (or converted into Notes) when data is exchanged from a system (B) that uses AIXM 5.2 for output towards a system (A) that uses AIXM 5.1.1 for input.

Change Proposal details

In the UML model:

In the Procedure class add the following attribute:

  • magneticVariation, type = ValMagneticVariationType, definition = “The angular difference between True North and Magnetic North that was used in the design of the procedure.”;
  • dateMagneticVariation, type = DateYearType, definition = “The date on which an associated magnetic variation was measured and revised for a procedure.”

The following UML class diagram shows the new attributes. For completeness sake, new attributes introduced through other change proposals  are also shown on the diagram.


Mapping AIXM 5.1.1 to AIXM 5.2 (forward)

The following algorithm shall be applied:

  • Not applicable

Mapping AIXM 5.2 to AIXM 5.1.1 (backward)

[MAPC-02] For each InstrumentApproachProcedure, StandardInstrumentArrival or StandardInstrumentDeparture that have magneticVariation and/or dateMagneticVariation  child elements from the three backward mapping options applicable in this case, the first two (discard the value or use an extension) are straightforward and do not need any further details. The 3rd option (backward mapping into a Note) is detailed in order to provide a complete description of this case and its conversion option.

The following mapping into Note algorithm is proposed:

  • Remove the magneticVariation element
  • Add an annotation.Note associated with the owner class or subclass having
  • purpose=“OTHER:BACKWARD_MAPPING”;
  • LinguisticNote.note=”magneticVariation: <value of magneticVariation>

 

  • Remove the dateMagneticVariation element
  • Add an annotation.Note associated with the owner class or subclass having
  • purpose=“OTHER:BACKWARD_MAPPING”;
  • LinguisticNote.note=”dateMagneticVariation: <value of dateMagneticVariation>

Mapping example

(Note: for mapping test data see: https://github.com/aixm/mapping_52_511/tree/master/AIXM-xxx) 

AIXM InputAIXM Output