8th usa/europe administration federal aviation atm r&d seminar · federal aviation 16 16...

Presented to:

Presented By:

Date:

Federal AviationAdministration8th USA/Europe

ATM R&D SeminarPaper #141: “Lateral Intent Error’s Impact on Aircraft Prediction”

ATM2009 R&D Seminar

Mike Paglione, FAA

July 1, 2009

Authors: M. Paglione, Federal Aviation AdministrationG. McDonald, Airservices AustraliaI. Bayraktutar, EUROCONTROLJ. Bronsvoort, Airservices Australia

2 2Federal AviationAdministration

ATM2009 - Paper #141: “Lateral Intent Error’s Impact on Aircraft Prediction”July 1, 2009

Presentation Overview• Background - Motivation

– Trajectory Based Operations– Trajectory Prediction Process Lateral Intent

• Flight Examples• Lateral Deviation Metrics• Measurements on ATC Operational Data• Impact on Conflict Predictions• Measurements on Airborne Operational Data• Conclusions



Background and Motivation• Trajectory Based Operations central to NextGen,

SESAR, and Australian ATM Strategic Plan• Trajectory Based Operations

– “Requires precise management of aircraft’s current & future position”– Thus, trajectory prediction needs to be more accurate than today– Lateral intent is a key component of this TP process

Initial condition

ABC

DEF

XYZ

Flight Plan: AAA123 B752 0450 310 XXX..ABC..DEF.BUC7.XYZ

BUC7

Route Conversion

XXX Aircraft trajectory modeling x(t),y(t),z(t

Constraint Specification

Lateral path initialization



Flight Example 1• Commercial carrier flying a B737-300• From Cleveland Ohio - To Denver Colorado• Climbs to FL340 after a series of cleared steps• Enters Denver en route center at FL 340• Starts smooth descent into Denver airport after

crossing radial distance 2 nm from AMWAY fix –follows SAYGE6 arrival



Flight Example 1 Continued



Flight Example 1 Continued• Focused on arrival

phase into Denver ARTCC

• ATC issues horizontal path stretch – not entered into ground automation

• Trajectory prediction exhibits large cross and along route errors

350

400

450

500

550

600

650

450 500 550 600 650 700 750

X-coord (nm)

Y-co

ord

(nm

)

Actual Path via Radar Reports

Predicted Trajectory



Flight Example 1 Continued

HORZ_ERR LAT_ERR LONG_ERR VERT_ERR CROSS_TRK_ERR ALONG_TRK_ERR TIME_ERR

16.9858 16.5285 -3.9148 0 16.5347 -3.9148 -34

455

460

465

470

475

480

570 575 580 585 590 595

X-coord (nm)

Y-c

oord

(nm

)

Track

TimeCoTraj81960

SpatialCoTraj81960

First Track Point, 83360s

Time Coincident Trajectory Point, 83360s

Spatially Coincident Trajectory Point, 83625s



Flight Example 2• Commercial carrier flight recorded in Washington ARTCC (ZDC) • Origin: Dallas Fort Worth, Texas • Destination: John F. Kennedy International Airport, New York• Hand-off into ZDC at 20:14 UTC and outbound to New York

ARTCC at 20:56 UTC during brief cruise at FL 240



Flight Example 2 Cont’d• TP generated 34 trajectories• Sampled 18 of the trajectories

to produce 109 measurements• Focus on trajectory build 74005

seconds (20:33:25 UTC) with 5 measurements below

Sample Time Measurement TimeLook

Ahead Time Horizontal ErrorCross-

track ErrorAlong-

track ErrorVerticalError

Clear Flag

Seconds Seconds HH:MM:SS SecondsNautical

MilesNautical

MilesNautical

Miles Feet

74040 74040 20:34:00 0 0.4 0.3 -0.3 0 0

74040 74340 20:39:00 300 0.1 -0.1 0.0 793 1

74040 74640 20:44:00 600 1.2 -0.5 -1.0 0 1

74040 74940 20:49:00 900 2.1 -0.1 2.1 2096 1

74040 75240 20:54:00 1200 34.6 11.9 -32.5 6952 1



Direction of flight track

dr

β

α

Cleared route

dn

da

Threshold Value (units)

D1 0.5 (nm)

D2 1.5 (nm)

D3 1.0 (nm)

P1 30 (deg)

Lateral Deviation Metrics



Measurements from ATC Operational Data:United States En Route Facilities

Descriptive Summary Statistics

Percentiles (nm)Airspace Source

SampleSize 25th 50th 75th

United States Airspace: Center Data

ZAB 427361 -0.399 0.014 0.562 1.352 15.326

ZAU 435974 -0.406 0.050 0.846 2.238 15.706

ZBW 303583 -0.570 0.081 1.700 3.727 22.329

ZDC 565728 -0.319 -0.013 0.356 1.795 13.964

ZDV 490275 -0.267 0.063 0.765 3.770 29.597

ZFW 384097 -0.809 0.039 0.951 1.266 12.797

ZHU 421271 -0.607 0.045 0.890 2.151 20.797

ZID 430507 -0.376 0.059 0.671 1.371 10.867

ZJX 540701 -0.714 0.056 1.100 1.361 11.486

ZKC 443290 -0.571 0.041 0.977 2.943 24.252

ZLA 367723 -0.337 0.014 0.743 5.652 26.665

ZLC 348567 -0.458 0.015 0.545 2.704 22.985

ZMA 377355 -1.000 0.068 2.100 6.397 44.761

ZME 437666 -0.481 0.034 0.844 2.333 18.434

ZMP 404147 -0.417 0.043 0.845 3.548 23.644

ZNY 258725 -0.352 0.057 0.723 1.803 13.986

ZOA 227412 -0.412 0.037 0.726 4.075 22.201

ZOB 472835 -0.418 0.005 0.630 1.356 10.306

ZSE 207031 -0.360 0.038 0.536 2.113 20.574

ZTL 566839 -0.535 0.048 0.820 1.734 13.964

Avg 405554 -0.493 0.039 0.857 2.579 20.816

Mean(nm)

Std Dev(nm)

• One day – seven hours of traffic

• All 20 ARTCCs• 50,000 flights• Over 8M

measurements



ZAB

ZAU

ZBW

ZDC

ZDV

ZFW

ZHU

ZID

ZJX

ZKC

ZLAZLC

ZMA

ZME

ZMP

ZNY

ZOA

ZOB

ZSE

ZTL

5

10

15

20

25

30

35

40

45

50

Stan

dard

Dev

iatio

n (n

autic

al m

iles)

0.5 1 1.5 2 2.5 3

Interquartile Range (IQR - nautical miles)

Measurements from ATC Operational Data: Cluster Analysis Results



Measurements from ATC Operational Data: Geography of Clusters

ZLA

ZOA

ZSEZLC

ZDV

ZAB

ZMP

ZKC

ZAU

ZID

ZME

ZFW

ZHUZMA

ZJX

ZTL

ZDC

ZOB ZNY

ZBW



Measurements from ATC Operational Data: Precipitation Weather Map of Same Date



Measurements from ATC Operational Data:Distributions of Three ARTCCs



0

20000

40000

60000

80000

100000

120000

140000

160000

180000

200000

220000

240000

Freq

uenc

y of

Mea

sure

men

ts49%

16%

9%

25%

47%

13%8%

32%30%

12%9%

49%

inne

rInC

onf

mid

InC

onf

mid

Non

Con

f

oute

rNon

Con

f

inne

rInC

onf

mid

InC

onf

mid

Non

Con

f

oute

rNon

Con

f

inne

rInC

onf

mid

InC

onf

mid

Non

Con

f

oute

rNon

Con

f

ZID ZM P ZM A

Lateral Adherence Status within ARTCC

Measurements from ATC Operational Data: Three ARTCC’s Lateral Adherence States



Measurements from ATC Operational Data:Lateral Deviation Statistics from Europe

• EUROCONTROL’s Flight Data Management Metrics Project published report July 2007

• Analyzed data set from November 2006– Approximately 27,000 flights from EUROCONTROL’s Central

Flow Management Unit– Supplied by 31 European Air Traffic Service Providers (ANSPs)– Utilized a software tool called EUROCONTROL Flight

Information Consistency Analysis Tool (EFICAT)• Results for two dimensional route analysis

– Grouped into major deviations > 50 nm off route and minor deviations between 20 and 50 nm

– Of 27,300 sample measurements…• 19% - minor deviations with average lateral deviation of 30 nm• 3% - major deviations with average lateral deviation of 73 nm



Impact on Conflict PredictionsConflict Event Counts For Each

Lateral Adherence StateAlert State In Out

106 102

111 97

12 12

7 27

118 114

χ2=5.04, df=1; p-value=0.025

232Totals

24No Alert

208Alert

Totals

χ2=84.742, df=1; p-value=0.000

1460669617645Totals

66547508 14162

67497413No Alert

307137 444

212232Alert

OutIn Totals

Encounter Event Counts For EachLateral Adherence StateAlert

State

Beyond paper applied method to operational conflict probe

Both conflict and non-conflict predictions effected by lateral adherence state.



Impact on Conflict Predictions: Sensitivity Analysis - Terms

• Probability of Alert – ratio of:– Number of conflict predictions (a.k.a. alerts) for min-max-ratio range to– Number of non-conflict events for same min-max-ratio range

• Min-max-ratio– Unit-less distance combines both dimensions of separation and

directly corresponds to standard separations.– Calculated on each position for each aircraft pair combo, such that:

( )[ ]ρ λ π= min max ,ik

i i

( ) ( )λ

δi

x ia xi

b yia yi

b

i=

− + −⎛⎝⎜

⎞⎠⎟

⎛

⎝⎜⎜

⎞

⎠⎟⎟

2 2

πυi

ia

ib

i

z z=

−

points track ofnumber total=k ;point track icurrent = i

feet. in baircraft ofpoint track i theof position altitude

feet; ina aircraft ofpoint track i theof position altitude

point;data track edsynchroniz i for the standard separation vertical=

positions y ingcorrespond theare , and

miles; nautical in baircraft ofpoint track i theof positionx

miles; nautical ina aircraft ofpoint track i theof positionx

point;data track edsynchroniz i for the standard separation horizontal =

where

th

th

th

th

th

th

th

=

=

=

=

bi

ai

i

bi

ai

bi

ai

i

z

z

yy

x

x

υ

δ



0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1 1.5 2 2.5 3 3.5 4 4.5 5 5.5Min-Max-Ratio Separation Factor

Prob

abili

ty o

f Ale

rt (#

Ale

rts/

#Enc

ount

ers)

All

InConf

OutConf

FitCurve(OutConf)

FitCurve(All)

FitCurve(InConf)

Impact on Conflict Predictions: Sensitivity Analysis



Measurements from Airborne Operational Data• From Airservices

Australia– ADS-C data– 778 flights

• 58 flights of type Airbus A330-300

• 168 flights of type Airbus A340-500

• 258 flights of type Boeing 747-400

• 294 flights of type Boeing 777-300

– Avg. 34.4 reports/flight

-0.3 -0.25 -0.2 -0.15 -0.1 -0.05 0 0.05 0.1 0.15 0.20

500

1000

1500

2000

LATERAL DEVIATION [nm]

CO

UN

T



Measurements from AirborneOperational Data:

Summary from Both U.S. & Australia

Descriptive Summary Statistics

Percentiles (nm)Airspace

Source

SampleSize 25th 50th 75th

United States Airspace: ADS-C Dataa

U.S. 39012 -0.018 -0.002 0.007 -0.001 0.184Australian Airspace: ADS-C Data

A.A. 26731 -0.019 -0.002 0.015 -0.003 0.026

Mean(nm)

Std Dev(nm)



Conclusions• TBO concepts will require accurate TP• Missing lateral intentlateral intent is significant TP error source • Metrics defined to capture lateral intent state•• LargeLarge samples of ground automation measurements

analyzed in both U.S. and Europe – U.S. reported lateral errors with an overall standard deviation of

about 21 nm and IQR of 1.35 nm– Europe reported 19% of their flight sample had lateral errors of

30 nm on average

• Impact on conflict predictions significant• Airborne ADS-C data measures from Australia and

U.S. much more precise – 100 to 1000 times!• Global challenge – needs global collaboration…

8th usa/europe administration federal aviation atm r&d seminar · federal aviation 16 16...

Documents