GML Profile

Owned by POROSNICU Eduard
Last updated: 2020 Sept 21

The AIXM XML Schema is a GML compliant schema, therefore all the GML types and entities are available for use in AIXM. This largely exceeds the aeronautical data requirements and it would unnecessarily complicate and increase the cost of the implementations. Therefore, a GML Profile for Aviation Data has been developed through the Aviation Domain Working Group (DWG) of the Open Geospatial Consortium (OGC) and is published as document OGC 12-028r1. The document provides a limited list of GML elements and types that need to be supported in an AIXM implementation. The same document also provides encoding rules for cases and data that are specific to the aeronautical domain, references to State borders that are used in the construction of an airspace horizontal projection, use of arc by centre point, etc.

Rule

The AIS Data Set shall comply with the GML limitations and usage rules stated in the OGC 12-028r1 document.

In addition, the encoding of an AIS Data Set is subject to a few more GML restrictions, mainly intended to avoid the provision of huge (above 1 GB) AIXM files when not really justified operationally.

Rule

The GML pointProperty element shall not be used, except when necessary:

  • in order to encode references to places, as stated in chapter Chapter 10 of the OGC 12-028r1 document;

  • in order to provide an accuracy value for a Curve point that is different from the accuracy of the whole Curve;

  • in order to provide an srsName for a Curve point that is different from the srsName of the whole Curve;

Recommendation

Sequences of more than two consecutive GML pos elements should not be used in the Data Set. The GML posList should be used instead.

References