Science Meeting-1 Lin 12/17/09 MIT Lincoln Laboratory Prediction of Weather Impacts on Air Traffic...

Science Meeting-1Lin 12/17/09

MIT Lincoln Laboratory

Prediction of Weather Impacts on Air Traffic Through Flow

Constrained Areas

AMS Seattle

Yi-Hsin Lin

25 January 2011

MIT Lincoln LaboratoryAMS Seattle 2011

Lin – 1/25/2011

Outline

• Forecast capacity model– Motivation– Algorithm

• Example: 4 August 2011 case study

• Results and verification

• Summary and further work


Lin – 1/25/2011

0 – 2 Hours“Local & Dynamic”

2 – 6 Hours“National & Planned”

Tactical Decision-Making

- Managing pilot deviations- Safe management of airborne holding- Dynamic, locally-coordinated reroutes- Implementing local airspace restrictions- Balancing airport arrival / departure fixes

Strategic Decision-Making

- Airspace Flow Programs - Playbook reroutes- Ground Delay Programs

Airspace Flow Programs “Playbook” Reroutes

Wea

ther

PHL

NY

Ground Delay Programs

Good Strategic Planning Manageable Tactical Environment

Good Tactical PlanningContributes to SuccessfulStrategic Plan

Strategic and Tactical PlanningSynergism


Lin – 1/25/2011

AFP Capacity Matrix: 4 August 2010, FCAA05

Valid Time (UTC)

Issu

an

ce T

ime (

UTC

)

Capacity Truth Low Medium High

A05 PrimaryDecision Period


Lin – 1/25/2011

Estimating Capacity: Process Overview

CoSPA Forecast

Weather Avoidance

Field

Blockage Algorithm

Resource Capacity


Lin – 1/25/2011

Weather Avoidance Fields

Flig

ht A

ltitu

de –

Ech

o To

ps (

16 k

m)

% VIL Coverage ≥ Level 3 (60 km)

Echo Tops

VIL

Historically, what kind of weather do pilots tend to deviate around?

WAF: Probability of deviation

0 5 25 50 75 95 100

As of summer 2009, WAFs have been integrated into the CoSPA shadow system.

0 10 20 30 40 50 60 70 80 90 100-22

-1

8 -

14

-1

0

-6

-2

2

6

10

1

4 1

8

22

1009080706050403020100


Lin – 1/25/2011

Severe Wx

Blockage Algorithm

Typ

ical

man

euve

rab

ility

( 4

0km

)

Time to coordinate deviation ( 4min* or 55km )

Least Significantly Impacted Path through Wx

Preferred Route

Blockage =where Weight = 1 / Normal Distance from Path

Route Segment

Weighted average centered on least significantly impacted path:

Sum ( Weight )Sum ( Weight * Precip>=Threshold )

Threshold = Maximum Precip along Path

Center of Jet Route

*based upon 825km/hr cruise speed

• Distance-weighted average of unavoidable WAF

• Takes into account maneuverability along a route

• Takes into account orientation of route

• Takes into account unavoidable weather


Lin – 1/25/2011

Resource Capacity

• FCAs A05 and A08 chosen because they are the most frequently used AFPs.

– Delays in the northeast can cause delays throughout the CONUS

• Route capacity = minimum capacity along each route

• AFP capacity = average of route capacities

FCAA05

FCAA08


Lin – 1/25/2011

Outline

• Forecast capacity model

• Example: 4 August 2011 case study– AFP vs. route capacities– Analysis of forecast error




Lin – 1/25/2011999999-XYZ 12/30/10

Weather and Traffic on 4 August 2010

17Z

18Z

19Z

20Z

21Z

22Z


Lin – 1/25/2011

4 August 2010: CoSPA Forecasts Reflected in Matrix Capacity Forecasts

TruthTruth

A05 PrimaryDecision Period

Valid Time (UTC)

Issu

an

ce T

ime (

UTC

)

Capacity Truth Low Medium High

Forecasts Valid at 19Z, 4 August 2010

6-hr 6-hr

5-hr 5-hr

4-hr 4-hr


Lin – 1/25/2011

Route vs. AFP Blockage Uncertainty

5-hour forecast 4-hour forecast

CoSPA forecasts valid at 22Z

All routesJ191AFP aggregate

• Forecasts are highly volatile at the route scale

• Errors are averaged out at the AFP scale

Matrix Capacity Forecasts Valid at 22Z


Lin – 1/25/2011

Outline



• Results and verification– Overall statistics– Error model



Lin – 1/25/2011

Overall Statistics

Forecast Time

For

ecas

t - T

ruth

Dataset: Summer 2010, except when CoSPA was down

High capacity most of the time

Forecast Error Distribution


Lin – 1/25/2011

Statistics by Impact and Time of Day

50-80

80-99

100

11-15Z 15-3Z 3-11Z


Lin – 1/25/2011

Observed CoSPA-based AFP Route Blockage Forecast Error Modes

• Analysis of both 2009 and 2010 CoSPA route blockage forecasts• AFP route blockage forecast error did not always decrease

monotonically with shorter look-ahead times• Uncertainty modeling needs to focus both on predicting route

blockage error and error behavior– Presenting model to predict route blockage error only

“Free and Clear” “The Dip” “The Climb”

“The Fall”

Truth valueForecast value

Fo

rec

as

t A

FP

B

loc

ka

ge

Forecast Look-ahead (minutes)


Lin – 1/25/2011

Factors, Predictors, and Results of AFP Blockage Error Modeling

Ro

ute B

lockag

e (0 – 1

.0)

Regression Tree Model Error Predictors

Forecast issue time

Forecast look-ahead

AFP blockage at issue time

Degree of convection already initiated

Std. deviation of route blockages at issue time

Proxy for current storm scale, organization, weather type

Forecast AFP blockage Scale and scope of predicted convection

Std. deviation of forecast route blockages

Proxy for predicted storm scale, organization, weather type

Blockages affected by severity, scale, and organization of storms throughout the domain

Fraction Correct mean{Interval} min{Interval} max{Interval}

0.8726 22.9575 0 83.7638

AFP Blockage Error Prediction Results from 2010 CoSPA

Regression tree may also be used to improve the blockage prediction


Lin – 1/25/2011

Outline






Lin – 1/25/2011

Summary

• Airspace Flow Programs are used to mitigate delays on strategic timescales

• CoSPA forecast → statements of resource capacity– Forecast scoring method– Tool for air traffic managers

• Capacities cannot be estimated at the scale of routes

• AFP capacities can be broadly estimated

• More work needs to be done on scoring and quantifying forecast uncertainty


Lin – 1/25/2011

Further work: AFP Forecast Scoring

• Relate capacity forecasts to actual traffic counts

• Incorporate error analysis to improve the forecast

• Scaling vs. uncertainty – transition from strategic to tactical


Lin – 1/25/2011

Thanks

• Josh Sulkin, Rich DeLaura• Bill Dupree• Mike Robinson• Joe Venuti• Marilyn Wolfson

Questions?

Science Meeting-1 Lin 12/17/09 MIT Lincoln Laboratory Prediction of Weather Impacts on Air Traffic...

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