wp2 current situation analysis – aircraft perspective philippe louyot (cena)

July 2004 – FALBALA/WP5/FOR3/D – CENA, DFS, EEC, NATS, Sofréavia & UoG

WP2 Current situation analysis – Aircraft

perspective Philippe Louyot (CENA)

CARE/ASAS Action

FALBALA ProjectDissemination Forum – 8th July 2004


WP2 objectives (1/2)

Assessment of the current situation from an aircraft

perspective using recorded radar data from: Frankfurt TMA (DFS)

London TMA (NATS)

Paris TMA (CENA)

En-route European Core Area (EUROCONTROL Maastricht)

Main assumption: all aircraft are ADS-B in-and-out

equipped


WP2 objectives (2/2)

How a pilot would see the traffic on a CDTI (Cockpit Display

of Traffic Information)

Qualitative assessment: for one selected aircraft of interest, CDTI fed by radar data (replay)

Quantitative assessment: for a set of aircraft of interest, computation and aggregation of indicators

(use of big amount of radar data hours)


Aircraft and flight operations of interest

VFR flights

IFR flights during 3 Package I AS applications:

enhanced traffic situational awareness during flight operations (ATSA-AIRB)

enhanced visual separation on approach (ATSA-VSA)

ATSA during enhanced sequencing and merging operations (ATSA during ASPA-S&M)


Qualitative assessment


Qualitative assessment method

Selection of one aircraft of interest from radar data

Traffic view from this aircraft of interest thanks to a CDTI

One aircraft of interest

All aircraft


CDTI features

The goal is not to design a CDTI, but only to illustrate the

issues

Airbus-like ND implementation

Ranges: from 10 up to 320 NM

Filtering: only vertical band filtering (TCAS legacy) Normal [-2700ft, +2700ft]

Above [-2700ft, +9900ft]

Below [-9900ft, +2700ft]

Automatic count of displayed aircraft (main indicator)


CDTI modes

ND modes: Arc and Rose Mode (Plan mode not retained)

Arc mode Rose mode Plan mode


Qualitative assessment

London Paris Frankfurt

VFR

ATSA-AIRB

VFR flight near

Toussus

GAT airfield

IFR

ATSA-AIRB

On LAM arrival

with holding

pattern

On initial and final

approach at CDG

On RNAV approach

at Frankfurt

IFR ATSA

during VSA

On final approach

at Frankfurt

IFR ATSA

during S&M

Merging in radar

vectoring area at

CDG


Illustration of ATSA-AIRB in London TMA


Illustration of ATSA-AIRB during VSA at Frankfurt airport


Illustration of ATSA-AIRB during S&M operation in Paris TMA


Qualitative results (1/4)

For an acceptable CDTI legibility, the maximum number of

displayed aircraft would have to be limited to about fifteen



For VFR flights, a CDTI is likely to improve safety from the

additional traffic information

Example:

A VFR flight arriving at

Toussus airport will

cross another

conflicting VFR flight

on another radio

frequency



For IFR flights, it is not obvious to decide which aircraft

must be filtered

Example: IFR during

initial approach at CDG.



A safety-oriented filter would be different from a situational

awareness oriented filter Safety: closer aircraft (in time or distance)

ATSA: aircraft inbound to the same runway for example

These aircraft may not be the same particularly in TMA & E-TMA


Quantitative assessment


Quantitative assessment method

Selection of all the aircraft of interest with their associated

period of interest

Computation of the number of displayed aircraft in all

display possibilities

Aggregation of this figure over several days


Selection of the aircraft of interest (1/3)

VFR flight: selection thanks to mode A code

IFR flight: selection thanks to flight phases recognition procedure matching for:

• STAR

• initial approaches

• RNAV approaches

• radio failure approaches for Radar vectoring

• final approaches

altitude based selection for cruise



The flight phases used are not exactly the same as the

standard ones Standard flight phases / used flight phases mapping

STAR

TOD

IAF

FAF/FAP

RWY

Cruise Descent Approach Final

RWY

Climb

(Take-off)

SID

Cruise Final Initial Approach

FL245

TOC

Radar vectoring

STAR start



UK France Germany Maastricht

VFR X X

CRUISE X X X

STAR X X

Initial Approaches X

Radar vectoring X

RNAV

Approaches

X

Final Approaches X X X

ATSA during

S&M

ATSA during

VSA

ATSA AIRB


Computation of seen aircraft (1/2)

Count of all aircraft in several defined volumes centred on

the aircraft of interest

The defined volumes are the combination of: Rose and Arc mode area (disc and heading related sector )

range: 10, 20, 40, 80 and 160 NM

altitude band filtering: ALL, NORMAL, ABOVE, BELOW

+2700ft

-2700ft


Computation of seen aircraft (2/2)

Count done for each antenna turn

Radar coverage taken into account

Radar coverage

Aircraft A with Rose mode

Aircraft B with Rose mode

Aircraft C with Arc mode


Aggregation and presentation

Aggregation by position of the aircraft of interest

Arc length on given procedure Geographic mosaic

Paris

0

5

10

15

20

25

30

35

40

0 20 40 60 80 100

Distance from IAF

Ave

rag

e n

um

ber

of

airc

raft

DVL_4H_MERUE

DPE_4E_MERUE

DJL_5P_OMAKO

TINIL_5E_OMAKO

AMB_4W_ODRAN

DPE_4H_MERUE

STAR: ARC 80NM BELOW (average of

displayed traffic)


Process overview Procedure XML file Radar data

Flight selection (with

period of interest)

Radar data sorted

by turn (all

plots)

Procedure data for arc

length computationLFPG STAR TINIL_OMAKO (cumul of 5 flights)

0

10

20

30

40

50

60

70

80

90

100

110

120

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100

distance from OMAKO

vis

ible

air

cra

fts

LFPG_STAR_TINIL_5E_OMAKO Ros10Nm_moy




LFPG_STAR_TINIL_5E_OMAKO Arc10Nm_moy





Process outcomes

For each phase of flight and each display selection Average of displayed traffic

Maximum of displayed traffic

Number of measures (traffic density of aircraft of interest)

Synthesis by flight phases

Paris

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140 160

Surveillance range

Av

era

ge

nu

mb

er

of

vis

ible

a

irc

raft

Rose

Arc

Rose Normal

Arc Normal

Rose Above

Arc Above

Rose Below

Arc Below


Quantitative results (1/3)

No direct link between the airspace density and the density

of traffic information

Cruising aircraft density

Maximum number of displayed traffic

(Arc Normal 80NM)



There is a lot of

difference between

average and maximum

figures

Arc 10 20 40 80 160

Avg Max Avg Max Avg Max Avg Max Avg Max

VFR 1 17 2 21 7 39 12 81 16 84

CRUISE 0 11 0 15 1 31 3 49 12 59

STAR 0 13 1 15 2 31 6 49 12 61

RNAV 0 5 0 7 1 8 1 9 1 12

INI 0 7 1 10 3 28 7 41 10 54

RVA 1 8 4 19 8 34 13 47

ILS 2 19 4 23 7 34

Average and maximum number of displayed aircraft per

phase of flight (Arc mode, Normal)



For VFR flights, a simple vertical filtering seems to be

sufficient

For IFR flights, need for a specific filtering possibly

depending of the phase of flight

The number of displayed aircraft is often too high even with the “Normal” altitude band filtering


Airborne surveillance requirements


Assessment method

Computation of the maximum number of detected aircraft

to help setting up airborne surveillance requirements Use of Maastricht radar data

Independently from the phase of flight

Rose 160NM

No vertical filtering


Results for airborne surveillance

Maximum number of 340 within a 160NM surveillance range

Extrapolated max 0.005 * range2 + 1.2 * range


Conclusions & recommendations


WP2 conclusions Initial assessment of traffic information possibly displayed on

a CDTI (for VFR & IFR) Illustrations through typical scenarios

Computation of maximum and average number of traffic

Evaluation of required airborne surveillance performances

Validation of the approach (radar data => current airborne traffic information

assessment)

Identified limitations of the approach Sensitivity of the results to the amount of cumulated data

Results near airports depend on radar coverage quality

Some bias due to aircraft on the ground


WP2 recommendations for future work

A better knowledge of the present ND selections in use

would be useful in order to reduce the large amount of

computed data

Standard deviation computation to complement the

maximum and the average assessment

Specific analysis focused on aircraft on the ground could

be performed

Use of mosaic should be preferred to the use of arc length


Questions & discussion

wp2 current situation analysis – aircraft perspective philippe louyot (cena)

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