Data Model Communication Patterns

56 Copyright © 2013 Open Geospatial Consortium.

7.2.1 Web Feature Service

WFS implementations are based on the OpenGIS Web Feature Service 2.0 Interface Standard OGC 09-025r1. Both service instances provided by Snowflake Software and COMSOFT provide a transactional interface for insertionupdate of newexisting AIXM 5.1 features.

7.2.2 Event Service

The Event Service ES implementations are based on the OpenGIS Sensor Event Service Interface Specification Discussion Paper OGC 08-133. Since the publication of this paper additional functionality has been developed within OWS test beds. Hence the term “Event Service” has been established as its capabilities are no longer limited to sensor measurements. ES implementations are based on the OASIS Web Services Notification standards family WS-N; WS-BaseNotification, WS-BrokeredNotification, WS-Topics 1.3 OASIS Standards which provide mechanisms to equip a service with publishsubscribe concepts. Requests to an ES are posted to interfaces with a SOAP 1.2 binding. These interfaces are defined by WSDL 1.1 descriptions.

7.3 Communication Patterns

This section illustrates the underlying data models as well as common service chains used for information dissemination with the data provision architecture.

7.3.1 Data Model

The communication between the involved components makes use of two concepts. Temporal changes to the AIXM features contained in the WFS data stores are encoded and published using the dedicated Event extension of AIXM 5.1 as specified by the Digital NOTAM Event Specification 1.0. For communications between WFS and ES instances the AIXMBasicMessage of this extension is used to carry the DNOTAMs. An exemplary message representing a Taxiway closure is provided in Listing 1. Listing 1 – Taxiway Closure DNOTAM Event. message:AIXMBasicMessage gml:id = FNS-Message xmlns:message = http:www.aixm.aeroschema5.1message xmlns:aixm = http:www.aixm.aeroschema5.1 xmlns:gco = http:www.isotc211.org2005gco xmlns:gmd = http:www.isotc211.org2005gmd xmlns:xlink = http:www.w3.org1999xlink xmlns:event = http:www.aixm.aeroschema5.1event xmlns:gml = http:www.opengis.netgml3.2 message:hasMember event:Event gml:id = uuid.ff3ab666-d8d0-428c-8304-5922ee4636b5 gml:description Closed taxiway due to maintenance gml:description gml:identifier codeSpace = urn:uuid: aa3ab666-d8d0-428c-8304- 5922ee4636b5 gml:identifier event:timeSlice event:EventTimeSlice gml:id = NOTAM_OWS9_17 gml:validTime gml:TimePeriod gml:beginPosition 2012-11-22T22:00:00Z gml:beginPosition Copyright © 2013 Open Geospatial Consortium. 57 gml:endPosition 2012-11-23T04:00:00Z gml:endPosition gml:TimePeriod gml:validTime aixm:interpretation BASELINE aixm:interpretation aixm:sequenceNumber 1 aixm:sequenceNumber aixm:featureLifetime gml:TimePeriod gml:beginPosition 2012-11-22T22:00:00Z gml:beginPosition gml:endPosition 2012-11-23T04:00:00Z gml:endPosition gml:TimePeriod aixm:featureLifetime event:name NOTAM_OWS9_17 event:name event:encoding DIGITAL event:encoding event:scenario TWY.CLS event:scenario event:textNOTAM event:NOTAM event:series A event:series event:number 0005 event:number event:year 2012 event:year event:type N event:type event:issued 2012-11-21T11:03:00 event:issued event:affectedFIR MKE event:affectedFIR event:selectionCode QMRLC event:selectionCode event:traffic IV event:traffic event:purpose NBO event:purpose event:scope A event:scope event:coordinates 42N87W event:coordinates event:radius 999 event:radius event:location MKE event:location event:effectiveStart 1211222200 event:effectiveStart event:effectiveEnd 1211230400 event:effectiveEnd event:text TWY CLOSED. event:text event:lowerLimit 000 event:lowerLimit event:upperLimit 999 event:upperLimit event:publisherNOF xlink:href = urn.uuid.c225ae5c-540f-4a48- 8867-809b393b2407 xlink:title = CIVIL AVIATION AUTHORITY event:NOTAM event:textNOTAM event:EventTimeSlice event:timeSlice event:Event message:hasMember message:hasMember aixm:TaxiwayElement gml:id = gmlID4640 gml:description Closed taxiway due to maintenance gml:description gml:identifier codeSpace = urn:uuid: 14BDAE02-1D6A-41F5-98AC- DE94D3253A53 gml:identifier aixm:timeSlice aixm:TaxiwayElementTimeSlice gml:validTime gml:TimePeriod gml:beginPosition 2012-11-10T22:00:00Z gml:beginPosition gml:endPosition 2012-11-23T04:00:00Z gml:endPosition gml:TimePeriod gml:validTime aixm:interpretation TEMPDELTA aixm:interpretation aixm:sequenceNumber 1 aixm:sequenceNumber aixm:availability aixm:ManoeuvringAreaAvailability aixm:operationalStatus CLOSED aixm:operationalStatus aixm:ManoeuvringAreaAvailability aixm:availability aixm:TaxiwayElementTimeSlice aixm:timeSlice aixm:TaxiwayElement message:hasMember message:AIXMBasicMessage

7.3.2 Service Chaining