There exist two families of AIXM versions:
- non-GML, which includes the earlier versions and from which only AIXM 4.5 is still in use
- GML-based, that started with AIXM 5.0 and includes AIXM 5.1, AIXM 5.1.1 and future versions.
There is also a difference in the data scope of these two families, as explained below.
GML stands for Geography Markup Language, a standard for the encoding and exchange of geographical related data provided by the Open Geospatial Consortium (OGC).
► AIXM 4.5 was published in 2005 as an update of the AIXM version 3.3, which was developed for the needs of the European AIS Database (EAD). It comprises an entity-relationship model and a custom XML schema that was derived from the entity-relationship model. The scope of the AIXM 4.5 version is limited to the most common static data contained in Aeronautical Information Publications (AIP), such as routes, navaids, airspaces, runways, etc. AIXM 4.5 is still in use in several national/regional systems around the world.
► AIXM 5.0 was published in 2008. Starting with this version, AIXM has three main components: a Data Model expressed in UML, a GML-compliant XML Schema and a Temporality Concept that enables the encoding of both static and dynamic AIS data (also known as "digital NOTAM"). These are complemented by a number of other specifications such as coding guidelines, business rules, etc. The scope of the AIXM 5.0 version is significantly enlarged as compared to AIXM 4.5, as it aims to support the encoding of the full AIP content. It also supports the encoding of dynamic data (NOTAM), although the first coding specification for Digital NOTAM comes with version 5.1.
► AIXM 5.1 followed soon (in 2010) as an updated version of the initial AIXM 5.0. Many existing implementations have made the transition from AIXM 4.5 to AIXM 5.1 and newly developed AIS systems use AIXM 5.1.
► AIXM 5.1.1 (minor update) is now available as the latest AIXM version. This minor version is fully compatible with the AIXM 5.1 version, meaning that forward/bacward conversions of data sets can be done without any data loss. Therefore, the two are presented together on this web site.
Future AIXM versions
After the publication of AIXM 5.1.1, the AIXM CCB has started evaluating the issues and improvement proposals that might be considered for the future regular AIXM update (version 5.2), which is expected to be published not earlier than March 2018. Please see the ► Governance pages for further details