MITRE-CAASD’s
systemwideModeler
State and Near-Term Plans
Pete Kuzminski
10 December 2008
© 2008 The MITRE Corporation. All rights reserved.
F066-B08-059
System-wide Analysis Framework
Convert to
.itin format
ATO-P
Demand File
Adaptation
GADS
Airframes File
Itinerary File
GRASP
Itinerary File
(adjusted)
Query Flight Info
Add flight info,
VFR, & adjust Taxi
Times
ETMS ASQP
Load Output
CRCT TM
DB
Load Value
Added Tables
Itinerary File
Link Flights
Transits File
Scenario Generation
Airframes File
(revised)
Generate
Background
Files
Load Input
Itinerary File
(revised)
Trajectories
File
Visualization
Performance
Metric Analysis
4-D Trajectory
Modeling
Equipment
Airspace
systemwideModeler
Airports
Annualization
Fixes
Post Processing
ARTCCs
Operators
Sectors
MIT
TSSIM
Airframe
TRACON
Sector Schedule
TRACONs
Background Files
2
Sector
Airport
Corridor
systemwideModeler Resources
GDP
© 2008 The MITRE Corporation. All rights reserved.
F066-B08-059
Analysis and Visualization Tools
© 2008 The MITRE Corporation. All rights reserved.
F066-B08-059
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)
4
© 2008 The MITRE Corporation. All rights reserved.
F066-B08-059
Model Purpose
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
5
© 2008 The MITRE Corporation. All rights reserved.
F066-B08-059
systemwideModeler
• Latest in NASPAC/DPAT/MLM lineage
– Designed and first released in 2006
Flights
Transits
Trajectories
Background
Airports
Sectors
etc.
Resources
(including
capacities)
Output
Simulation engine
Flight events
Resource events
• Written in SLX, a PC-based simulation language
• Active, disciplined CAASD development effort
• ~30k lines of code
• Scenario runs in 5-15 minutes
6
© 2008 The MITRE Corporation. All rights reserved.
F066-B08-059
Model Approach
Flights
• Start with initial 4D
trajectories (from
external trajectory
model)
plans
plans
plans
• Characterize “use”
by flights
• Monitor flight plans/progress
• Change plans to
respect constraints
plans
plans
constraints
Flights’ only response to constraints
is to delay passage of points.
(Cancellations, re-routing, and altitude changes
are responses being researched.)
7
Resources
• Regulate resource
“condition”, e.g., occupancy
• Issue constraints to
individual flights
A resource only constrains a flight
once it enters a planning horizon.
© 2008 The MITRE Corporation. All rights reserved.
F066-B08-059
Airport
Tactical Separation
hourly
arrivals
frontier of feasible throughput
Sensitive to:
• runway layout and use
• standard procedures
• separation rules and minima
• variability and buffers
• fleet mix
• aircraft performance
Capacities scheduled by:
• weather
• winds
• ceiling
• configuration selection rules
hourly
departures
Arrivals
• Spacing enforced to maintain arrival priority rate
Departures
• Spacing enforced to maintain feasible throughput over
user-specified period
Arrivals
Departures
 

t-x
8
 






 

  ...
t
ready time
© 2008 The MITRE Corporation. All rights reserved.
F066-B08-059
Airport
Demand Management
Airport Demand Manager
Anticipates demand
A
A
D
A
A AA AA A
D
DD DDD
Enforcement Mechanisms
Anticipate landing/takeoff times
A
AAR/ADR
A
D
Ground/Departure Gateways
Delay pushback
Picks operating points
arrs
Arrival Gateway
Delays arrival TRACON entry
or
Merging and Spacing
Publishes rates
dpts
Spreads delay
AAR
ADR
9
© 2008 The MITRE Corporation. All rights reserved.
F066-B08-059
Sector
Occupancy Limited
• Capacities typically MAP value or
some transformation
6

– May change on schedule
1
9

8

2
A
7

• Airspace assigned to sectors may
also change on schedule
• Sector entries are delayed
3
• Uses several “services” available
to resources
4
10

B
5
– Avoids cycling
– Relieves resource developers of
several burdens
– Allows developers to focus on
characterizing use and anticipating
conditions
10
© 2008 The MITRE Corporation. All rights reserved.
F066-B08-059
Sector
Workload 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?
 
flight workload
Modeled workload distributed over transit of flight
• Handoff and coordination tasks
• Monitoring and spacing
• Conflict detection and resolution
• Delay absorption
t
Entry
Exit
sector workload
threshold
Flight’s entry delayed until addition of modeled workload
to sector’s anticipated workload acceptable
• 15-minute moving sum of workload is governed
t
delayed entry
When resource informed of changes to plan,
it updates workload as appropriate
• For example, delayed exit causes additional work
Entry
11
change
Exit
notification
t
© 2008 The MITRE Corporation. All rights reserved.
F066-B08-059
Other Resources
• Arrival and departure TRACON
• Miles-in-trail restrictions
• Ground Delay Programs/Ground Stops
• Airframes
12
© 2008 The MITRE Corporation. All rights reserved.
F066-B08-059
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
13
© 2008 The MITRE Corporation. All rights reserved.
F066-B08-059