temporality and encodings
DESCRIPTION
Temporality and Encodings. Concepts and Examples. Presented by Brett Brunk Aeronautical Information Management (AIM) group Federal Aviation Administration – United States. Topics. Temporality Why is it necessary AIXM 5 temporality concepts A NAVAID example Example AIXM 5 Encodings - PowerPoint PPT PresentationTRANSCRIPT
Singapore Workshop – Technical Focus - 16 June 2008
Temporality and Encodings
Concepts and Examples
Presented by Brett BrunkAeronautical Information Management (AIM) group
Federal Aviation Administration – United States
Singapore Workshop – Technical Focus - 16 June 2008
Topics
Temporality● Why is it necessary● AIXM 5 temporality concepts● A NAVAID example
Example AIXM 5 Encodings● Components of an AIXM 5 exchange file● New Airspace● Temporary change to airspace usage
Singapore Workshop – Technical Focus - 16 June 2008
Why do we need temporality?
Time is essential for aeronautical informationFor operational reasons, distinction
between:● Permanent changes● Temporary status
Two levels:● Life of the feature● Changes in properties
Singapore Workshop – Technical Focus - 16 June 2008
Temporality Model
Definition● A model that incorporates the concept of time
Key assertions● All features are temporal with start of life and end of life
● Example, A new air traffic control sector● All features change over time
● Example, A VOR is out of service for a day AIXM Temporality Model
● Relates features to the time extent in which they are valid● Provides various means to describe the time extent
Singapore Workshop – Technical Focus - 16 June 2008
Time varying properties
Time
P1
FeatureProperties
value 1 value 2 value 3 value 4
P2 value a value b
P3 value x
P4 value z
P5 value $ value #
Singapore Workshop – Technical Focus - 16 June 2008
The basic Time Slice model
Time
P1
FeatureProperties
value 1 value 2 value 3 value 4
P2 value a value b
P3 value x
P4 value z
P5 value $ value #
Singapore Workshop – Technical Focus - 16 June 2008
The basic Time Slice model
P1
FeatureProperties
P2
P3
P4
P5
TimeSlices: TS 1 TS 2 TS 3 TS 4 TS 5 TS 6 TS 7 TS 8
Singapore Workshop – Technical Focus - 16 June 2008
The basic Time Slice model
P1
FeatureProperties
P2
P3
P4
P5
TimeSlices: TS 1 TS 2 TS 3 TS 4 TS 5 TS 6 TS 7 TS 8
states
Singapore Workshop – Technical Focus - 16 June 2008
The basic Time Slice modelUML
Singapore Workshop – Technical Focus - 16 June 2008
P1
FeatureProperties
P2
P3
P4
P5
TimeSlices: TS 1 TS 2 TS 3 TS 4 TS 5 TS 6 TS 7 TS 8
temporaryvalue w
TS "temp”
event
Temporary events (digital NOTAM)
Singapore Workshop – Technical Focus - 16 June 2008
Temporary events
Two kinds of Time Slices● Baseline = describes the feature
state (the set of all feature’s properties) as result of a permanent change;
● Temporary Delta = describes the transitory overlay of a feature state during a temporary event.
AIXMFeature
identifier : CodeUUIDType
<<feature>>
AIXMFeatureTimeSlice
validTimeinterpretationfeatureLifetimeproperty1property2property3...
1..* +time varying properties1..*
Singapore Workshop – Technical Focus - 16 June 2008
Current status of a feature
P1
FeatureProperties
P2
P3
P4
P5
TimeSlices: TS 1 TS 2 TS 3 TS 4 TS 5 TS 6 TS 7 TS 8
temporaryvalue w
SNAPSHOT
SNAPSHOT = describes the state of a feature at a time instant, as result of combining the actual BASELINE Time Slice valid at that time instant with all TEMPDELTA Time Slices applicable at that time instant.
Singapore Workshop – Technical Focus - 16 June 2008
P1
FeatureProperties
P2
P3
P4
P5
TimeSlices: TS 1 TS 2 TS 3 TS 4 TS 5 TS 6 TS 7 TS 8
temporaryvalue w
TS "temp”
Permanent changes Permanent changes
event
PERMDELTA = A kind of Time Slice that describes the difference in a feature state as result of a permanent change.
Singapore Workshop – Technical Focus - 16 June 2008
P1
FeatureProperties
P2
P3
P4
P5
Time
Time Slice Types
PERMDELTA 1(start of life)
PERMDELTA 2 PERMDELTA 3PERMDELTA 4
PERMDELTA 5 PERMDELTA 6PERMDELTA 7
PERMDELTA 8PERMDELTA 9
(end of life)
TEMPDELTA
temporaryvalue w
SNAPSHOT
Singapore Workshop – Technical Focus - 16 June 2008
Summary - Time Slice types
BASELINE = A kind of Time Slice that describes the feature state (the set of all the feature’s properties) as result of a permanent change;
PERMDELTA = A kind of Time Slice that describes the difference in a feature state as result of a permanent change;
TEMPDELTA = A kind of Time Slice that describes the transitory changes of a feature state during a temporary event;
SNAPSHOT = A kind of Time Slice that describes the state of a feature at a time instant, as result of combining the actual BASELINE Time Slice valid at that time instant with all TEMPDELTA Time Slices applicable at that time instant.
Singapore Workshop – Technical Focus - 16 June 2008
An Example: Navaid frequency change
Imagine that AML Navaid undergoes an upgrade that changes its frequency from 112 MHz to 113.2 MHz…
1. Schedule permanent change to coincide with AIRAC update cycle
2. Shutdown AML before the upgrade3. Perform the upgrade4. Start AML in test mode to evaluate
change
Singapore Workshop – Technical Focus - 16 June 2008
An Example: Navaid frequency change
AML Navaid undergoes an upgrade that changes its frequency from 112.0 MHz to 113.2 MHz…
Singapore Workshop – Technical Focus - 16 June 2008
Topics
Temporality● Why is it necessary● AIXM 5 temporality concepts● A NAVAID example
Example AIXM 5 Encodings● Components of an AIXM 5 exchange file● New Airspace● Temporary change to airspace usage
Singapore Workshop – Technical Focus - 16 June 2008
AIXM is based on International Standards
Aeronautical Information Exchange Model (AIXM)
ISO 19107 Spatial
ISO 19108 Temporal
ISO 19115 Metadata ISO 19136 Geography Markup Language (GML)Universal Markup
Language (UML)
Extensible Markup Language (XML)
Conceptual standards Exchange standards
Singapore Workshop – Technical Focus - 16 June 2008
Extensible Markup Language (XML)
XML – Extensible Markup Language
● Have you looked at whatis underneath a webpage?
● XML has a similar look to HTML
Computer readable● Electronic exchange● Vendor supported
<h2><a href="sdat2/html/download.htm"> SDAT 5.7 Release</a></h2>
<h3 class="byline">New Features >></h3>
<p> <ul>
<li>Create traffic collections based on a sector number. (Flights flown through specified sector(s))</li>
…
<h2><a href="sdat2/html/download.htm"> SDAT 5.7 Release</a></h2>
<h3 class="byline">New Features >></h3>
<p> <ul>
<li>Create traffic collections based on a sector number. (Flights flown through specified sector(s))</li>
…
<RunwayDirection>
<Designator>20L</Designator>
<VFRPattern>RIGHT</VFRPattern>
</RunwayDirection>
…
<RunwayDirection>
<Designator>20L</Designator>
<VFRPattern>RIGHT</VFRPattern>
</RunwayDirection>
…
Web Page HTMLWeb Page HTML
XML DocumentXML Document
Singapore Workshop – Technical Focus - 16 June 2008
Key Concept: Geometry and GML
Geometry important property of aeronautical information
● Airspace polygons● Airport Reference Points● Navaid location
Singapore Workshop – Technical Focus - 16 June 2008
Key Concept: Geometry and GML
ISO 19136 Geography Markup Language (GML)
● Vendor independent standard
● Based on XML● Good industry adoption
Singapore Workshop – Technical Focus - 16 June 2008
Creating a new airspace
<?xml version="1.0" encoding="UTF-8" ?> <Airspace xmlns=“http://www.aixm.aero/schema/5.0” xmlns:gml="http://www.opengis.net/gml/3.2” xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:gmd="http://www.isotc211.org/2005/gmd" xmlns:gco="http://www.isotc211.org/2005/gco"
xsi:schemaLocation="http://www.aixm.aero/schema/5.0 ../xsd/AIXM_Features.xsd" gml:id="A00001">
<gml:identifier codeSpace="http://ead.eurocontrol.int">0bf9537f-27f0-4650-a75f-125006366e51</gml:identifier>
<timeSlice><AirspaceTimeSlice gml:id="VID001">…</AirspaceTimeSlice>
</timeSlice>
</Airspace>
An AIXM Airspace Feature
Unique Identifier for the Airspace. Computer readable
Container for the timeslices that make up the airspace
End of the Airspace Feature
Definition of the airspace
Singapore Workshop – Technical Focus - 16 June 2008
Creating a new airspacecontinued
<Airspace …><gml:identifier …>…</gml:identifier> <timeSlice>
<AirspaceTimeSlice gml:id="VID001"><gml:validTime>
<gml:TimePeriod gml:id="VID002"><gml:beginPosition>2006-03-15T00:00:00</gml:beginPosition><gml:endPosition indeterminatePosition="unknown" />
</gml:TimePeriod> </gml:validTime> <interpretation>BASELINE</interpretation>
<featureLifetime><gml:TimePeriod gml:id="VID003">
<gml:beginPosition>2006-03-15T00:00:00</gml:beginPosition> <gml:endPosition indeterminatePosition="unknown" /> </gml:TimePeriod> </featureLifetime>
… other properties</AirspaceTimeSlice> </timeSlice>
</Airspace>
Baseline timeslice containing all feature
properties
Period of validity for timeslice
Period of validity for the Airspace feature
Singapore Workshop – Technical Focus - 16 June 2008
Creating a new airspacecontinued
<Airspace …><gml:identifier …>…</gml:identifier> <timeSlice>
<AirspaceTimeSlice gml:id="VID001">…
<type>TSA</type> <designator>EBT15</designator> <name>LO-RENINGE UAV AREA</name> <controlType>MIL</controlType> <class> <AirspaceLayerClass> <class>G</class> </AirspaceLayerClass> </class>
<geometryComponent>…</geometryComponent></AirspaceTimeSlice>
</timeSlice> </Airspace>
Airspace Feature properties
Airspace shape and volume
Singapore Workshop – Technical Focus - 16 June 2008
Creating a new airspacecontinued
<Airspace …><gml:identifier …>…</gml:identifier> <timeSlice>
<AirspaceTimeSlice gml:id="VID001"> …<geometryComponent>
<AirspaceGeometryComponent><theAirspaceVolume>
<AirspaceVolume> <upperLimit uom="FL">95</upperLimit> <upperLimitReference>STD</upperLimitReference> <lowerLimit uom="FT">4500</lowerLimit> <lowerLimitReference>MSL</lowerLimitReference>
<horizontalProjection> … </horizontalProjection> </AirspaceVolume> </theAirspaceVolume> </AirspaceGeometryComponent> </geometryComponent> </AirspaceTimeSlice> </timeSlice> </Airspace>
Upper and lower limits
GML definition of horizontal boundary
Singapore Workshop – Technical Focus - 16 June 2008
Creating a new airspacecontinued
<Airspace …><gml:identifier …>…</gml:identifier> <timeSlice>
<AirspaceTimeSlice gml:id="VID001">…
<geometryComponent><AirspaceGeometryComponent>
<theAirspaceVolume><AirspaceVolume>
…<horizontalProjection></horizontalProjection>
</AirspaceVolume> </theAirspaceVolume> </AirspaceGeometryComponent> </geometryComponent> </AirspaceTimeSlice> </timeSlice></Airspace>
<horizontalProjection><Surface gml:id="VID005"
srsName="urn:ogc:def:crs:OGC:1.3:CRS84"><gml:polygonPatches>
<gml:PolygonPatch><gml:exterior>
<gml:LinearRing><gml:pos>51.0155 2.5713</gml:pos> <gml:pos>51.0125 2.6277</gml:pos> <gml:pos>50.9472 3.0000</gml:pos> <gml:pos>50.7633 2.9991</gml:pos>
</gml:LinearRing></gml:exterior>
</gml:PolygonPatch> </gml:polygonPatches> </Surface></horizontalProjection>
Singapore Workshop – Technical Focus - 16 June 2008
Demonstration
Viewing AIXM features in a commercial product
● LuciadMap’s prototype AIXM Viewer