Project Objectives

• demonstrate the maturity of the “digital NOTAM” concept
• validate the AIXM 5 timeslice model for managing permanent and temporary changes
• check the completeness of (selected) AIXM 5 feature definitions
• involve AIS Offices from ECAC State as test digital NOTAM data providers
• identify potential digital NOTAM users and applications.

Application Scope

In order to achieve these objectives, Pulsar has developed and hosted a complete set of applications, including:

• an Oracle Database entirely modeled against the AIXM 5.0 Model, including Spatial functionalities and an implementation of the Temporality Model
• an AIXM 4.5 Mapping Software for automatically importing static data (baselines) into the application from EAD (through an SDO connection)
• a user friendly web based Data Provider Interface allowing Data Providers to:
  • encode existing NOTAMs in an AIXM 5.0 format
  • select impacted features through a graphical map (on a subset of selected AMDB features)
  • preview the horizontal projection of airspaces on a satellite map
• a user friendly web based Data User Interface allowing Data Users and system implementers to:
  • view encoded data in textual and AIXM formats
  • compare the temporary change with the initial valid baseline
  • preview the horizontal projection of airspaces on a satellite map
  • subscribe to email notifications to automatically receive new data (events, features and timeslices in AIXM 5.0 format)
• an AIXM 5.0 Mapping allowing the application to export the database content into valid AIXM 5 XML files.

Main Concepts

AIXM Data Related Flow




Pulsar's Extranet and xNOTAM Specific Integration





Oracle Spatial and interactive Google Maps

• Transparent overlays use polygons coming directly from the database
• Data managed with JavaScript
• Visual/interactive selection of RunwayElements and TaxywayElements on a map

• 5 GB data export/import -> 8h/conversion scripts, 1h export, 3h import x all environments
• Conversion of spatial data
  -> database corruption : upscaling the server was necessary
  -> Oracle doesn’t like virtual machines (VM Ware or ESX server), it become slow, we switched on a quadri-core/4GB physical server
• No arcs & circles in geodetic coordinates system -> management by polygons: 1 circle realised with aprox. 1 000 points
• Spatial GML not fully compliant with AIXM 5 GML -> translation procedures.

Main Functionalities

• Allows encoding of new airspace restrictions, including their usage and timetables in one single step
• Ability to encode multiple points at once to define an airspace (allows copy/paste from NOTAM Messages)

• Implemented according to Temporality Document
  • ‘Continuity’ (Feature) only contains immutable data: UUID
• Identification not straightforward
  • Required information may be missing in delta timeslice
  • The natural key (human readable) evolves in time
  • Sometimes built on a parent’s natural key, also evolving in time
  • Runway Centreline Point is identified by
    • Associated Airport Heliport designator and name
    • Associated Runway Direction designator
    • Role

Temporality issues:

• Dimensions of time: actual time (4th dimension) - modeled with START and END dates
• Allows knowing since when the information on a particular event was available
• Could be critical in historical investigations

• Stored in the same table as other timeslices (same « kind »)
• Easier developments
• May slow the search of timeslices
• In average, 4 snapshots for 1 timeslice
• Varies from 2:1 to 15:1 (the more over- lapping timeslices, the more snapshots)

• Compatible with SkyView

• Implemented as database views

• Bounding box queries require a spatial index
• Materialized views
  • Updated on regular time interval (no real-time queries)
  • Geometries may become out of date between 2 updates
• Triggers
  • Development time depends on the complexity of the feature.

Facts & Figures

• Generated AIXM5 XML Files:
  • 35.600 files (email notification system and the reporting functionalities)
  • 110 MB of XML files
• Production database:
  • Database size (tablespace total of the 3 main schema): 30 GB compressed
  • 58 GB of cached AIXM XML (events and timeslices)(length of extracted string with Select statements)
  • Including 18 GB from Session 1 timeslices
• Project of 700 MD, 2 to 6 FTE (Full Time Equivalent), depending on project phase
• Duration: 17 months, from July 2007 to December 2008
• More than 135 screens
• 5 databases instances & 7 separate environments
• 21 Oracle Schemas to manage
• 110.000 lines of code