Data Coding Policies

Required roles: AIS Navigation Data via Cloud — Roles
Base endpoint: none
Reference documents: AIXM 5.2 schema set (aixm.aero) · ICAO Doc 7910 Location Indicators · RFC 7946 The GeoJSON Format
Attribution: show ibonav.aero wherever this data is displayed
Data sources: none
Last updated: 18 OCT 2026

About the reference documents: Related Documents and Resources

Rules applied when the ibonav.aero Navigation Database is coded.

Provenance

Every feature carries its provenance (see AIXM Schema Extension; GeoPackage columns data_provider, data_originator, data_effectivity).

Field Coding
Data Provider The provider of the data. If the data was taken as provided, directly or with a simple conversion, the name of that provider. If the data was produced by Ibosoft AIS, or created by processing in Ibosoft AIS: Ibosoft AIS
Data Originator The original source of the data. For data produced by Ibosoft AIS (e.g. an AIP of Ibosoft AIS): Ibosoft AIS
Data Effectivity Data updated by the ICAO AIRAC system: DD MMM YYYY (AIRAC YYNN), e.g. 01 OCT 2026 (AIRAC 2610)
AIRAC-dependent data that was corrected: suffix v2, v3 …, e.g. 01 OCT 2026 (AIRAC 2610) v2
Data updated independently of the AIRAC cycle: DD MMM YYYY (Non-AIRAC), e.g. 23 JUN 2026 (Non-AIRAC)

Important: Data Effectivity does not state that the data was published on that date. It states the date the data was added or last checked. For data updated automatically every cycle, the value is normally renewed every cycle; if it is older, the data has not been checked or updated in the database since that date. Users are responsible for checking the data against valid sources.

Aerodrome AIXM Identifier and ICAO Location Indicator

Where a source provides the two values separately, they are carried over as given. No external source lacks them, so no other rule is applied to source data.

In data produced by ibonav.aero:

Case ICAO Location Indicator AIXM Identifier
1. The aerodrome has a valid ICAO location indicator (ICAO Doc 7910) The ICAO location indicator The ICAO location indicator (required by the AIXM schema)
2. The aerodrome has an unofficial location indicator Empty The unofficial location indicator
3. Neither Empty Generated (see below)

Generated AIXM Identifier (case 3):

  • First two characters: the location indicator nationality letters of the country of the aerodrome (required by the AIXM schema).
  • Next four characters: not set by the schema; a ibonav.aero rule combining a local area code of the country and a sequence number starting from 1.

Türkiye: LTxxyy

Part Meaning
LT Nationality letters of Türkiye
xx Province code of the province where the aerodrome is
yy Sequence number in order of addition, starting from 01

Example: LT1401

VOR/TACAN Declination

If the source does not provide the station declination of a VOR or TACAN, no assumed value is used; the field is left empty.

Area Geometry Coding

Area geometries follow the polygon rules of RFC 7946 (GeoJSON):

Rule Application
Ring orientation Exterior rings counter-clockwise, holes (interior rings) clockwise (RFC 7946 §3.1.6)
Orientation plane Computed with x = longitude, y = latitude
Coordinate reference WGS 84 (EPSG:4326)
Antimeridian Geometries crossing the 180° meridian are split into parts on each side (RFC 7946 §3.1.9)
Coordinate order AIXM: latitude longitude (gml:posList, EPSG:4326 axis order); GeoPackage: longitude, latitude

The orientation is applied in the AIXM files and is therefore the same in the GeoPackage.

Line Geometry Coding

Line geometries (routes etc.) that cross the antimeridian are split into two parts for compatibility with web maps. A Designated Point (DP) of type OTHER is added at the split point; its designator and name are empty, and it is described in its annotation. Each split route segment also gets an annotation.

Feature Annotation purpose Note
Added Designated Point REMARK Automatically generated by the AIS system to display antimeridian crossings on web maps.
Split Route Segment REMARK Route segment automatically split by the AIS system at the antimeridian for display on web maps.

In the GeoPackage these notes are in the annotationRemark column.