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Document Sample
Introduction to AIXM Federal Aviation
Administration
XML and XML
Schemas
AICM/AIXM Training
Presented to: AICM/AIXM Training
By: Brett Brunk (CNAC for FAA)
Date: August 2005
AIXM is XML
Web Page HTML
Web Page HTML
<h2><a href="sdat2/html/download.htm">
<h2><a href="sdat2/html/download.htm">
• XML – Extensible SDAT 5.7 Release</a></h2>
SDAT 5.7 Release</a></h2>
Markup Language <h3 class="byline">New Features >></h3>
<h3 class="byline">New Features >></h3>
– Have you look at what <p> <ul>
<p> <ul>
is underneath a web <li>Create traffic collections based
<li>Create traffic collections based
on a sector number. (Flights flown
on a sector number. (Flights flown
page? through specified sector(s))</li>
through specified sector(s))</li>
– XML has a similar …
…
look to HTML
XML Document
XML Document
<Person>
<Person>
<Name>Brett Brunk</Name>
<Name>Brett Brunk</Name>
<Phone>2022880420</Phone>
<Phone>2022880420</Phone>
</Person>
</Person>
…
…
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XML defined
• Contains tags
– <Name>, <Person>
• Contains content <Person>
<Person>
– Brett Brunk <Name>Brett Brunk</Name>
<Name>Brett Brunk</Name>
– 2022880420 <Phone>2022880420</Phone>
<Phone>2022880420</Phone>
</Person>
</Person>
• Selfdescribing
…
…
– <Name> tells you want
Brett Brunk is.
• Standards based
– Full vendor support
– Very COTS and developer
friendly
See http://www.w3schools.com/xml/default.asp
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XML Syntax
• Every XML element has an open tag and a
closing tag
• All XML documents have a root element
• All XML elements must be nested
• All XML attributes are quoted
Root Attribute
<Person Age=“34”>
Element/Tag <Name>Brett Brunk</Name>
<Phone>2022880420</Phone>
</Person>
… Closing Tag
Nesting
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XML Schema
• How the content of an XML document is
defined
– “Contract specifying exactly what to expect in the XML
document” <?xml version="1.0" encoding="UTF8"?>
<xs:schema elementFormDefault="qualified"
attributeFormDefault="unqualified"
xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name="Person">
<xs:complexType>
<xs:sequence>
<xs:element name="Name"/>
<xs:element name="Phone"/>
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:schema>
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From AICM to AIXM
AICM AIXM
AIXM
SIGNIFICANT_POINT <AIXMSnapshot>
<Vor>
<VorUid>
<codeID>AML</codeID>
VOR <geoLat>34.3928N</geoLat>
<geoLon>123.4333W</geoLon>
</VorUid>
LIMITATIONS …
</AIXMSnapshot>
• Representation of AICM in XML
• AIXM Vocabulary
– Features – AICM entities such as Runways and VORs
• AIXM Grammar
– Snapshots – Aeronautical data at a specific date and time
– Updates – Changes to aeronautical data
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Relation with AICM
• For every AIXM feature there
exists a corresponding AICM
entity
• Some AICM entities
correspond to complex local
elements in the XML schema
– For example,
PROCEDURE_LEG
corresponds to the <Plg>
complex child element in the
declaration of the SidType
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AIXMXML Features
• Basic AIXMXML information unit is a feature
– It corresponds to a real thing in the aeronautical environment
• such as a NAVAID, a runway, a route segment, an airport, etc.
– XML complex types in the AIXMFeatures.xsd subschema file
– may have attributes and relationships
• child elements of the feature type
<xsd:complexType name="VorType">
<xsd:annotation>
<xsd:documentation>VOR</xsd:documentation>
</xsd:annotation>
<xsd:sequence>
<xsd:element name=…
…
</xsd:sequence>
</xsd:complexType>
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Naming convention
• Feature names
– 3letter abbreviations L
• Likely to be changed/improved in AIXM 5.x
• Feature attributes
– AICM attribute name in Java style
– First token (lower case) indicates the type
• CODE_ID > codeId
• VAL_ELEV > valElev
• Etc.
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Main difference between AICMAIXM
• AICM – no declaration of unique identifiers
• AIXM – declares feature unique identifiers
– Uses natural keys
• As opposed to artificial identifiers (gUID)
– Every AIXM feature has a FeatureUid complex type
• Airport: AhpUid (codeId)
• Airspace: AseUid (codeType, codeId)
• VOR navaid: VorUid (codeId, geoLat, geoLong)
• Etc.
– Why necessary
• For encoding AICM relationships
• For AIXMUpdate messages
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AIXM – relationship encoding
AIXM AICM
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Natural Keys
• Based on AICM entity attributes and/or
relationships
– Examples
• Aerodrome/Heliport (codeId)
• Airspace (codeType, codeId)
• Runway (txtDesig, rel. to Aerodrome/Heliport)
• Route Segment (rel. to start point, rel. to end point, rel. to route)
• Designated point (codeId, geoLat, geoLong)
– Declared as “featureUidType” in the XML schema
• There are AICM entities with no simple natural key
– Consider as complex characteristic of another feature
• Typical examples: timetable, border vertex, procedure leg, navaid
usage limitation in a sector, etc.
• declared as complex child element in other (related!) features in
the XML schema
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Natural Keys
featureUidType
Complex child element
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Schema modules
AIXM 4.0
AIS Database update application
AIXMUpdate.xsd AIXMSnapshot.xsd
AIXM application messages
AIXM core files AIXMFeatures.xsd
AIXMUpdate AIXMSnapshot
DataTypes.xsd DataTypes.xsd
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AIS Database update application
• Messages
– AIXMUpdate
– AIXMSnapshot
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