1. DATA PROCESSING TECHNIQUES FOR CONFLICT DETECTION ON AIRPORT SURFACE
J. García Herrero1, J.A. Besada Portas2, Gonzalo de Miguel2, Javier Portillo2
(1) Universidad Carlos III de Madrid. (SPAIN)
(2) Universidad Politécnica de Madrid. (SPAIN)

2. INTRODUCTION Airport traffic automation Databases SMR Radar GNSS +ADS
Multilateration
Mode-S
GNSS +ADS
Radar
ASR
SMR
Databases de

3. INTRODUCTION
A-SMGCS
CONTROLLER WORKING
POSITION
DISPLAY
CONTROL
PLANNING
GUIDANCE
SURVEILLANCE & DATA FUSION
INFORMATION
SYSTEMS
SENSORS
AIRPORT SURFACE
TERMINAL AREA
Scenario: aircraft, vehicles, routes, demanded operations,
runways, taxiways, stands, TMA, etc.

4. A-SMGCS’ CONTROL FUNCTION
FUNCTION: Analyse the traffic situation and check safety level
Acess/Separation Rules: safety margins between aircraft and vehicles, depending on areas, visibility, conditions, …
Restricted Areas: areas temporarily closed or restricted to some types of mobiles
OBJECTIVE: Automatically detect all the conflictive situations, with anticipation time enough  
INFORMATION SOURCES: Tracking from Surveillance Function and Airport DataBases

5. TYPES OF CONFLICTS (I) RUNWAY INTRUSION CONFLICTS (1.2) (1.1) (1.3)
RWY 2
RWY 1
(1.2)
(1.1)
(1.3)

6. TYPES OF CONFLICTS (II)
SEPARATION CONFLICTS
TAXIWAY
COLLISION
(5.1.1)
(5.1.2)

7. TYPES OF CONFLICTS (III)
NON-AUTHORISED MOVEMENTS
DEVIATIONS FROM GMP
(last point)
(2.1)
EXIT
COLLISION
COLLISION
RUNWAY
RUNWAY
non-taxiing runway
(2.2)
NO ENTRY
(2.3)
TAXIWAY
......
(1.1)
(1.4)
TAXIWAY
wrong direction

8. FUNCTION STRUCTURE ALARMS TRACK LIST EXTRA-POLATION PAIR SELECTION
COLISION CONFLICTS
ALARMS
-INTRUSION
-NON-AUTH.
-GMP DEV.
CONFLICTS
AIRPORT
LAYOUT
AIRCRAFT
VEHICLES
GMP

9. LOCATION ON MAP Airport representation Location with uncertainty ¢  x, y 2K â t å l
estimated
position
covered area
in element 1
in element 2
Airport representation
Location with uncertainty

10. DETECTION LOGIC INTRUSION CONFLICTS RUNWAY ACTIVATION terminal area
take-off threshold
SEARCH ON LINKED AREAS
runway hot area
close exitways, taxiways,...

11. DETECTION LOGIC SEPARATION CONFLICTS LOC. ON AIRPORT LAYOUTv
BREAKING
DISTANCE 2 2 2
PAIRS SEARCH ON SAME AND LINKED AREAS 1
minimum
BREAKING
DISTANCE 1
separation v 1
dmin

12. DETECTION LOGIC SEPARATION CONFLICTS (II) A,B: head-on approaches
C,D: tail-chase approaches

13. CONFLICT DETECTION CRITERION
Several components in definition of separation:
Minimum physical distance (SEPmin): safe separation in any case
Minimum Relative Separation (MRS) : minimum separation in ideal estimation, function(relative positions, relative velocities)
Alarm Threshold: takes into account uncertainty in positions estimated/extrapolated
V1=25m/s
V2=5,15,25,40 m/s
SEPmin
MRS AT

14. STATISTICAL MODEL Model uncertainty in tracking information:
observation, estimation, extrapolation,…

15. STATISTICAL MODEL Test Design: Three alternatives analysed:RM
CRITICAL
REGION
Test Design:
Three alternatives analysed:
Bound to conflict region probability
Test 2 over worst case in critical region’s edge (Haest95)
Linear approximation to estimated distance
distance reached
with probability P D
conflict region d z s d Th d
measured

16. SOME RESULTS (I) 100m f=45º f=0º 125m scenario 1 scenario 2
Scenario 1: False Alarm probability
Probability of
detection

17. SOME RESULTS (II) s =10m f =0º Scenario2: Detection probability
Probability of detection

18. CONCLUSIONS
Developed and analyzed data processing techniques embedded in an ASMGCS’ control system
Integration of tracking output from surveillance function (data fusion) + lateral information airport layout, airport configuration,…
Criteria for detecting the main types of surface conflicts as a function of relative situation and quality of estimations
Analysis of several statistical tests for conflict detection to attain the best levels of performance
Design: probability of detecting conflict situation (95% when d=SEPmin)
Satisfied by all alternatives
The probability of raising false alarms increases when this accuracy is lower. The best performance is attained with third alternative