This requirement applies to information concepts and data concepts. It applies when the "main" trace (see SWIM-INFO-016 and SWIM-INFO-017) is to an AIRM concept that has a wider meaning. The purpose is to add traces in order to make the mapping as precise as possible. The diagram below shows where multiple traces have been added to a single mapping.
These additional traces make clear why the information definition's concept is regarded as narrower than the AIRM concept.
The specification uses the example of "Target Startup Approval Time" (TSAT). The figure below is taken from the AIRM. It includes the three elements needed from the AIRM in order to "build" the TSAT. These are: StartUp, DateTimeWithPlanningType and CodePlanningStatusType.
The following table explains that these are used:
Information Definition Concept
The time provided by ATC taking into account TOBT, CTOT and/or the traffic situation that an aircraft can expect to receive start-up/push-back approval.
Time at which the aircraft starts up.
This is the "main" trace expected by SWIM-INFO-017.
|DateTime||This is the data type trace expected by SWIM-INFO-017.|
This is the additional trace necessary to qualify the semantics of the StartUp. Namely, it represents which planning status is associated with the StartUp.
If any of the additional traces is missing, then the semantics of the information definition would not be described accurately in terms of AIRM concepts, as the semantic would miss some building block.
As a rule of thumb, the need for additional mappings may occur when the information definition's concept is:
[ ] Each additional trace to fully describe the narrowing of the concept being mapped is to the correct AIRM concept.
The example below shows how the multiple traces can be embedded into an XML schema. The second trace is an additional trace needed to make the semantic correspondence specific. This is extracted from the complete example. Further help on mappings can be found on the Understanding and recording mappings page.
<xs:element name="tobt" type="don:TargetOffBlockTime" id="donlon003" minOccurs="1" maxOccurs="1"> <xs:annotation> <xs:documentation>The Target Off-Block Time value to be set. TOBT is the time that an operator / handling agent estimates that an aircraft will be ready, all doors closed, boarding bridge removed, push back vehicle present, ready to start up / push back immediately upon reception of clearance from the TWR. </xs:documentation> <xs:documentation> <semanticCorrespondence> <mapping> <note>The TOBT maps to OffBlockReady, not OffBlock. This is clear in the definition.</note> <trace type="informationConceptTrace">urn:aero:airm:1.0.0:LogicalModel:Subjects:Flight:FlightEvent:OffBlockReady@time</trace> <trace type="narrowingTrace">urn:aero:airm:1.0.0:LogicalModel:Subjects:Common:Codelists:CodePlanningStatusType@TARGET</trace> </mapping> </semanticCorrespondence> </xs:documentation> </xs:annotation> </xs:element>