F066-B08-059 © 2008 The MITRE Corporation. All rights reserved. MITRE-CAASD’s systemwideModeler State and Near-Term Plans Pete Kuzminski 10 December 2008

F066-B08-059© 2008 The MITRE Corporation. All rights reserved.

MITRE-CAASD’s systemwideModeler

State and Near-Term Plans

Pete Kuzminski

10 December 2008

© 2008 The MITRE Corporation. All rights reserved.F066-B08-059

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systemwideModeler

Background Files

Scenario Generation4-D Trajectory

Modeling

Post Processing

systemwideModeler Resources

ETMS

Query Flight Info

GRASPItinerary File

Transits File

Itinerary File

Equipment

Airspace

Airports

Fixes

ARTCCs

Operators

Sectors

Sector Schedule

TRACONs

Convert to .itin format

ATO-P Demand File

Generate Background

Files

GADS

TSSIM

Airport

TRACON

CorridorSector

Airframe

GDP

MIT

DB

Load Input

Load Output

Load Value Added Tables

Performance Metric Analysis

Add flight info, VFR, & adjust Taxi Times

Adaptation

Link Flights

Itinerary File (revised)

Trajectories File

Airframes File (revised)

Visualization

Annualization

CRCT TM

ASQP

Airframes File

Itinerary File (adjusted)

System-wide Analysis Framework


Analysis and Visualization Tools


Recent Applications

• Benefits assessment

– Data Communications Segment 1

– NextGen Implementation Plan

• Problem identification

– Future Airport Capacity Task (FACT)

– Future Airspace Capacity and Efficiency Study (FACES)

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Model Purpose

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To estimate the aggregate and network effects of changes to the NAS

• Delay and load are primary metrics of interest• By phase of flight• By element, e.g., airport, sector, system

• Because output is as-flown trajectories, other effects could be interpreted, e.g., fuel burn

• Demand: volume, fleet mix• Capacity: airport, TRACON, sector, fixes and airways• Structure: airspace and routes• Traffic management

• Time- vs. distance-based• First-come first-served vs. other priority policies


systemwideModeler

• Latest in NASPAC/DPAT/MLM lineage

– Designed and first released in 2006

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FlightsTransits

Trajectories

BackgroundAirportsSectors

etc.

Resources(includingcapacities)

OutputFlight events

Resource eventsSimulation engine

• Written in SLX, a PC-based simulation language

• Active, disciplined CAASD development effort

• ~30k lines of code

• Scenario runs in 5-15 minutes


Model Approach

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Flights plansplans

plans

Resources

plansplans

constraints

• Start with initial 4D trajectories (from external trajectory model)

• Change plans to respect constraints

• Characterize “use” by flights

• Monitor flight plans/progress

• Regulate resource “condition”, e.g., occupancy

• Issue constraints to individual flights

Flights’ only response to constraintsis to delay passage of points.

(Cancellations, re-routing, and altitude changes are responses being researched.)

A resource only constrains a flightonce it enters a planning horizon.


AirportTactical Separation

frontier of feasible throughputhourlyarrivals

hourlydepartures

Sensitive to:• runway layout and use• standard procedures• separation rules and minima• variability and buffers• fleet mix• aircraft performance

Arrivals

Departures

t-x tready time

Arrivals

• Spacing enforced to maintain arrival priority rate

Departures

• Spacing enforced to maintain feasible throughput over user-specified period

. . .

Capacities scheduled by:• weather• winds• ceiling• configuration selection rules

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AirportDemand Management

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dpts

arrs

A A A A A A A A AA A

D D DD D DDD

AAR

ADR

Airport Demand ManagerAnticipates demand

Picks operating points

Publishes rates

Merging and SpacingSpreads delay

Enforcement Mechanisms

Ground/Departure Gateways

or

Anticipate landing/takeoff times

AAR/ADR

Delay pushback

Arrival GatewayDelays arrival TRACON entry


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SectorOccupancy Limited

A

B

1

2

3

4

5

6

7

8

9

10

• Capacities typically MAP value or some transformation

– May change on schedule

• Airspace assigned to sectors may also change on schedule

• Sector entries are delayed

• Uses several “services” available to resources

– Avoids cycling

– Relieves resource developers of several burdens

– Allows developers to focus on characterizing use and anticipating conditions


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SectorWorkload Limited

As flight approaches sector, its nature and activity in the sector is evaluated• Commercial flight? GA? Military? Equipage?• Previous/next sectors?• Transitioning altitude?• Requires spacing for arrival airport?• Involved in aircraft-aircraft conflict?

Modeled workload distributed over transit of flight• Handoff and coordination tasks• Monitoring and spacing• Conflict detection and resolution• Delay absorption

flight workload

tEntry Exit

sector workload

t

delayed entry

thresholdFlight’s entry delayed until addition of modeled workloadto sector’s anticipated workload acceptable• 15-minute moving sum of workload is governed

tEntry Exit

When resource informed of changes to plan, it updates workload as appropriate• For example, delayed exit causes additional work

changenotification


Other Resources

• Arrival and departure TRACON

• Miles-in-trail restrictions

• Ground Delay Programs/Ground Stops

• Airframes

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Near-Term Work

• Improved ground gateway

• More strategic traffic management for en route congestion

• Departure fix congestion

• Dynamic assignment of airframes and cancellations

• Arrival TRACON

– Better representation of routes

– Reduced acceptance in presence of load and delay

– Reduced variability of final approach fix delivery

• Demand scenario generation

– To address variability in demand and airport configurations

– To improve realism in airframe utilization, routes, fleet mix/equipage

• Re-routing to avoid weather and congestion

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Documents

F066-B08-059 © 2008 The MITRE Corporation. All rights reserved. MITRE-CAASD’s systemwideModeler State and Near-Term Plans Pete Kuzminski 10 December 2008