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[AIXM-566] Airspace with point location for navigation warnings

[AIXM-566] Airspace with point location for navigation warnings

Owned by georgiana.andrei04
Last updated: 2024 Aug 27 by ADAM STYLES

ID:

AIXM-566

target version:

AIXM 5.2

version:

1.0

last updated:

28 SEP 2022

status:

APPROVED


Description

Add association from AirspaceVolume to Point with location role.

Rationale for change

See https://aixmccb.atlassian.net/browse/AIXM-221

There are many examples of “navigation warnings” published in AIP ENR 5.5, which have a simple latitude/longitude location. For example, Parachute Jumping Exercises (PJE), glider flying locations, High Intensity Radio Transmission Area (HIRTA), etc. See AIP France, Belgium, Netherlands for examples. The extent of the activity is not provided, therefore it is not possible to code a real volume for such areas.

The current AIXM 5.1.(1) model allows such navigation warnings to be encoded as instances of Airspace. However, this requires a horizontal projection (Surface) defined at least as a full Circle. An artificial radius of 1m is sometimes used, but this can be misinterpreted as an official value, which is not the case.

An additional association between the AirspaceVolume class and a Point is proposed in order to allow a simplified coding of such navigation warnings.

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 AirspaceVolume class:
    • add a new composition relationship AirspaceVolume isSituatedAround Point
      • 0…1 on the Point side, “location” role name, definition = “A single position used as geographical reference for the AirspaceVolume, in particular when a precise horizontalProjection is not provided.”
      • add a new “dependency” relationship from Point to SignificantPoint.

Note: this dependency is similar to the dependency relationship between Surface and SignificantPoint. It is implemented with a pointProperty, as explained in the GML Profile for aviation data.

The following UML class diagram shows the additional relationship:

Mapping AIXM 5.1.1 to AIXM 5.2 (forward)

Not applicable

Mapping AIXM 5.2 to AIXM 5.1.1 (backward)

[MAPC-00] For each AirspaceVolume that has a location element and no horizontalProjection:

  • add a horizontalProjection with geometry of type Circle, centred on the Point provided in the location element and with a radius of 1m
  • remove the location element.

[MAPC-02] For each AirspaceVolume that has a location element and  also a horizontalProjection:

From the three backward mapping options discussed for 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:

  • Add an annotation.Note associated with the AirspaceVolume class having
  • purpose=“OTHER:BACKWARD_MAPPING”;
  • LinguisticNote.note=”location: <location//gml:pos value>
  • propertyName=horizontalProjection.
  • remove the location element.

Mapping example

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

AIXM InputAIXM Output