MVAs and AIXM

Dr. Navin Vembar

The CNA Corporation

AIXM5 in the Real World

Outline

• What are MVAs and MIAs?

• Modernizing the MVA and MIA Process

• The MVA/MIA Model

• Moving Forward

Outline

• What are MVAs and MIAs?

• Modernizing the MVA and MIA Process

• The MVA/MIA Model

• Moving Forward

What are MVAs and MIAs?

• Minimum Vectoring Altitudes and Minimum Instrument Altitudes– Used to ensure that aircraft avoid obstacles and

terrain

• MVA used by TRACONs with ARSR radar– Each radar has its own MVA chart

• MIAs used by facilities with ASR radars– Usually ARTCCs or large TRACONs

• Need to automate for safety reasons

How Areas are Built

• Each MVA or MIA area is constructed from polygon “modules”– Many areas have

holes in them to avoid particular obstacles or terrain points

• Picture on the right is from the SDAT tool

Outline

• What are MVAs and MIAs?

• Modernizing the MVA and MIA Process

• The MVA/MIA Model

• Moving Forward

The Process, As-Is

• Facilities design their charts– Use sectional charts for obstacle and terrain

information

• They submit the chart by paper to the National Flight Procedures Office– Fill out relevant forms including information about

the controlling obstacles or terrain for each area

– NFPO can reject or accept the chart

– Done yearly

The Modern MVA Lifecycle

RVM, ACES

Design (SDAT) Submit

Flight Procedures (NFPO) Validation

Implement

New obstacle review (using

NASR and OE/AAA)

Concept of Operations

RVMACES

RVMACES

Store (NASR)

SDAT For Automation

• The Sector Design and Analysis Tool (SDAT) is the cornerstone of MVA/MIA modernization

• SDAT allows designers to create MVA and MIA areas– Validates against digitized obstacles– Validates against USGS NED data for terrain– Computes necessary polygon mathematics

(buffering, adding, subtracting)

SDAT For Automation

• SDAT is a tool that has existed since 1998– Currently version 5.12

• Uses AIXM 3.3 for representation of MVA and MIA data– But, we’re talking about AIXM5!

• After approval, the SDAT backend will– Convert to AIXM 5 – Submit to the National Airspace Resources

(NASR) Repository

Outline

• What are MVAs and MIAs?

• Modernizing the MVA and MIA Process

• The MVA/MIA Model

• Moving Forward

Data Model for MVAs

Airspace(from Airspace)

<<feature>>

Unit(from Organisation)

<<feature>>ResponsibleParty

<<datatype>>M

MinimumAlti tudeAreas<<feature>>

Point(from Geometry)

<<object>>

MinimumInstrumentAlti tudeAreas<<feature>>

MinimumVectorAlti tudeAreas<<feature>>

MinimumAltitudeAreaList<<object>>

VerticalStructure(from Obstacle)

<<feature>>

ElevatedPoint(from Geometry)

<<object>>MinimumAltitudeArea

<<feature>>

1

hasUnit

1

1hasDesigner

1

0..*hasApprover 0..*

1

hasRadarLocation

1

1

hasAreas

1 1

hasAreas

1

0..n0..n

1

hasControll ingObstacle

1

hasHighTerrainPointNoBuffer

hasHighTerrainPoint

What Are We Leveraging?

• AIXM 5 Features & Objects– Feature Collections– Airspace– Unit– (Upcoming) Services– ResponsibleParty

Feature Collections

• Key to the whole process

• MVA Charts are features which contain MVA Areas, which are again features

• Solution: Feature Collections

• Features can be aggregated into a larger feature known as a feature collection

Other Features

• Unit – Representing facility information

• Service– Representing facility radar

• The key is reuse– Why model something already done for you?– Attributes and elements are optional, only fill

in what you need

Conversion

• Problem: SDAT creates data in AIXM 3.3

• We want to move to AIXM 5 for new web service and exchange communications– Tool of choice: XSLT– Difficulties

• Different GML models for representing geometries• Converting between DMS and decimal degrees

Implementation Choices

• Now that we have the model, what about implementation?– How to represent aggregate geometries within

an Airspace?• GML+xlink is very flexible and thus brings up this

question

– How much of the dependent feature and object data do we need?

Implementation Questions

• How to implement model while storing and disseminating?– What will be efficient?– What will be useful?

• Model and implementation are separate issues– Consider users and the level of flexibility required

• Persistence Web Server– MVA/MIA: Only one “user”, so specification of implementation

can be limited

• General consumers– Can use any implementation that meets the model

requirements

Implementation - Storage

• Efficient?– As we may reuse modules across different areas,

store those once• Provides spatial value as when the AIXM is moved to Oracle

SDO, these may be indexed separately

• Useful?– We are reusing nodes, but we never manipulate them

• Implementation– Consists of a list modules– Areas use xlink and Airspace aggregation to refer to

the modules

Implementation - Editing

• Efficient?– Again, use shared modules

• Useful?– Now, a user may move a single node and have it

affect multiple areas– Requires node-level data

• Implementation– Consists of a list of nodes– Build modules from nodes using xlink references– Areas use xlink and Airspace aggregation to refer to

the modules

Outline

• What are MVAs and MIAs?

• Modernizing the MVA and MIA Process

• The MVA/MIA Model

• Moving Forward

Plans

• Using Web Services– “Black Boxing” MVA and MIA data

• Achieved decoupling

– Will be used in obstacle proposal process

• Persistence of AIXM data– Using Oracle 11’s GML handling to convert

directly to SDO

Conclusion

• AIXM 5 is contributing to a successful implementation of MVA and MIA storage and dissemination

• Gaining leverage from its components– AIXM 5 features– GML– XML

Questions?