AIXM-391 Allow lower case in names

Description

The data type TextNameBaseType is modified to allow also the use of lowercase characters.

Rationale for change

See https://aixmccb.atlassian.net/browse/AIXM-236

In the current model, place and feature names are constrained by the TextNameType to use only uppercase characters, numbers and some special characters. This "uppercase only" restriction was imposed in the initial AIXM versions in order to facilitate the interoperability with aviation messages exchanged over AFTN (such as NOTAM, FPL and MET messages).

For the Digital NOTAM specification it has been recently agreed to promote the use of normal "sentence case" for the text of the event description. The use of a mix of upper and lower characters for airport names, airspace names, etc. would also improve the readability of static data encoded in AIXM. This would have no negative impact on the transmission of data over AFTN because the conversion lowercase to uppercase is straightforward and unambiguous. 

Therefore, the current pattern of TextNameType should be relaxed to also allow lower case characters [a..z].

Impact assessment

There is no impact on existing implementations as the current AIXM 5.1.(.1) data remains fully valid against AIXM 5.2.

When receiving data from AIXM 5.2 implementations, current AIXM 5.1(.1) systems will have to be able to map back the “name” elements that use lower case characters, as described in the mapping rules further in this document. The mapping is straightforward.

Change Proposal details

In the UML model:

• Modify the TextNameBaseType as follows:
• Remove the ‘specialisation’ association with Character3Type
• Add a ‘specialisation’ association with Character2Type
• Add the following pattern
• ([A-Z]|[a-z]|[0-9]|[, !"&#$%'\(\)\*\+\-\./:;<=>\?@\[\\\]\^_\|\{\}])*

Mapping AIXM 5.1.1 to AIXM 5.2 (forward)

Not applicable.

Mapping AIXM 5.2 to AIXM 5.1.1 (backward)

[MAPC-00] The following algorithm shall be applied:

• For each of the following elements, replace any lowercase [a-z] character with the equivalent [A-Z] uppercase character:
• AerialRefuelling/name
• AeronauticalGroundLight/name
• AirportHeliport/name
• Airspace/name
• Airspace/localType
• Apron/name
• CallsignDetail/callSign
• City/name
• ContactInformation/name
• ContactInformation/title
• DesignatedPoint/name
• GeoBorder/name
• GuidanceLine/name
• HoldingAssessment/patternTemplate
• Navaid/name
• NavaidEquipment/name
• ObstacleAssessmentArea/safetyRegulation
• ObstaclePlacement/pointType
• OnlineContact/protocol
• OrganisationAuthority/name
• PostalAddress/city
• PostalAddress/administrativeArea
• PostalAddress/postalCode
• PostalAddress/country
• Procedure/name
• RadarEquipment/name
• RadarSystem/model
• Road/designator
• Route/name
• Service/name
• SpecialDate/name
• SpecialNavigationStation/name
• SpecialNavigationSystem/
• SurveyControlPoint/designator
• Unit/name
• VerticalStructure/name

Mapping example

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

AIXM 5.2	AIXM 5.1(.1)