Conclusion and Recommendation Specification and Usage of Conformance Targets

14 Copyright © 2011 Open Geospatial Consortium.

5.4.1.2 Available Options Solutions

The DNES should explicitly state that DNOTAM Event data can be encoded using container formats other than AIXMBasicMessage so that this can be taken into account by developers and users.

5.4.1.3 Conclusion and Recommendation

To avoid confusion a note should be added to the DNES to clarify that the specification allows more than one container format. This note could be added in a section that describes the usage of DNOTAMs in communications between system entities. There are multiple aspects that could be described there, see sections 5.4.2 and 5.4.3. 5.4.2 Multiple Events per Message 5.4.2.1 Problem Statement and Description The DNES does not seem to contain a requirement that a message only contains one dnotam:Event. The currently described scenarios suggest that only one Event is needed. Therefore, automatic validation rules e.g. via schematron may be developed based upon this constraint. However, if this constraint is not valid then such developments would be flawed.

5.4.2.2 Available Options Solutions

The DNES should explicitly state if multiple dnotam:Events can be communicated in one message e.g. an AIXMBasicMessage or other container used to transport the data so that this can be taken into account by developers and users.

5.4.2.3 Conclusion and Recommendation

A clarification telcon with the sponsors revealed that for the current scenarios defined in the DNES one Event per message would in fact suffice. However, it was also said that in the future the DNES may define more complex scenarios where more than one Event may be included per message e.g. having one Event referring to another. In addition, use cases like data synchronization between two system entities may be preferable. Simple validation tools may benefit from a constraint that there is only one Event per message. Use cases that do not necessarily require validation - like the data synchronization use case - could then still work with multiple Events per message. However, the schematron rules developed during the testbed support multiple dnotam:Events per message. To summarize, there does not seem to be a need to add a “one Event per message constraint” to the DNES. To avoid confusion a note should be added to the DNES to clarify that the specification allows more than one Event to be communicated in a single message. This note could be added in a section that describes the usage of DNOTAMs in