ads-b trials : feedback · 2013-09-23 · 5 air systems division trial set-up the set-up for ads-b...
TRANSCRIPT
Air Systems Division
ADS-B Trials : Feedback
ICAO Surveillance Seminar for the NAM/CAR/SAM
Lima, Peru 9th - 10th May 2008
Air Systems Division2
Implementing ADS-B (1)
When considering operational ADS-B implementation, a number of items need to be defined:
� the scope of ADS-B surveillance: for situational awareness or for separation,
� the type of airspace: en-route, TMA, upper, lower, with or without existing radar coverage, and associated coverage
� the time frame considered,
� Preparation and publication of necessary regulatory material
� Organisation of controller training, users educations,
Air Systems Division3
Implementing ADS-B (2)
The relevant evolution of ground infrastructure must be considered:
� Network of ADS-B ground stations, and supported services, including communications
� Upgrade of the automation systems in order:� to receive and process ADS-B data,
� to create tracks derived from ADS-B data (priority scheme or data fusion)
� to display the resulting tracks with appropriate symbols
� possibly to display associated DAPs
� possibly to compute and display RAIM outages
Air Systems Division4
Need for trials
To support the analysis of ADS-B implementation in a state or a region, ADS-B trials need to be set-up to allow the direct observation and analysis of a number of parameters:
� the status of the aircraft fleet in this state or region wrt ADS-B equipage,
� the local characteristics of the GPS signal, which directly generate the aircraft position reported by ADS-B
� The impact of local environment (physical, radio, …) on the expected performance of the ADS-B surveillance
The results of such trials definitely contribute to a decision for implementation.It will support dialogue with airlines for buy-in a nd plans to equip (or understand reasons for reluctance),It will provide inputs for the preparation of safet y case, etc, …
Air Systems Division5
Trial set-up
The set-up for ADS-B trial can be simple,as it generally consists of:� a single channel ADS-B ground station (redundancy is not
strictly necessary), � associated with a GPS equipped / RAIM reporting site
monitor, � a local or remote and control system (depending on where
the station is installed), � data recording capability and� replay / data analysis tools, � and the availability of experts resource to carry out the
analysis
Air Systems Division6
Trial set-up (2)
The trial will allow to provide more results when
� A radar covers the same area as the ADS-B ground station� Compare ADS-B and radar reports, tracks
� Several radar covers at least a part of the area covered by the ADS-B Ground Station and a multi-radar tracking system is applied� Multi-radar tracks can provide an accurate reference track
Air Systems Division7
Which data to analyse? (1)
Methodology of Data Analysis� Which data to be recorded for analysis depends on the intended
operations i.e. whether it is en-route overflights, en-route domestic, approach in large TMA, and/ or approach to small airports.
� Depending on the operations required, the performance assessmentmight differ.
An example of trial objectives can be:� Collection and analysis of the quantity and registration numbers of
ADS-B equipped aircraft received by ADS-B ground station, on a daily basis over a period of 6 months;
� Conclusion on the validity of the reports received to allow surveillance and/or separation of aircraft based on ADS-B
� Comparison of ADS-B targets to radar targets functionality and recommendations
Air Systems Division8
Which data to analyse? (2)
Analysis to be carried out on data collected may include the following:� For aircraft sorted by airline / type / …the analysis of the content of the
squitter (i.e. what are the fields provided, level of NUC, …)
� For the whole population of aircraft observed, establish a data base identifying the aircraft with “good” ADS-B equipment and those with “bad”ADS-B equipment; the “bad” characteristic may come from an already identified issue or be a new one
� For selected tracks with good NUC values assess:� position accuracy, including investigation on along tracks error (on-board latency)� update rate figures
� the ground station range and compare with theoretical model
� For selected tracks evaluate % of equipped aircraft ?
Air Systems Division9
Feedback on trials
Air Systems Division10
Thales involvement in trials
Thales contributed to a number of trials, including� Germany, Langen with DFS� Spain, Madrid with AENA� Island, Reykjavik � Senegal, Dakar, ASECNA� India, Delhi, AAI� South Korea, Seoul (Incheon)� CRISTAL MED : France (Marseille, Corsica), Greece &
Cyprus � Cristal Toulouse (France), as part of Eurocontrol Cascade � Hong Kong� Indonesia
Air Systems Division11
Eurocontrol Cascade – Cristal Toulouse - 2006
Air Systems Division12
Trial objectives
� Check conformity between ADS-B data sent by aircraft (flight test recorded data at sensors level) and data received by ground station (raw data).
� Verify that rate of transmission is compliant with ED-102/DO-260/DO-260A MOPS (airborne, ground)
� Evaluate the ADS-B ground station coverage (airborne, ground).
� Evaluate transmitted Flight ID and evaluate the percentage of aircraft sending a correct one (compliant with ICAO model).
� List airliners with ADS-B capability
� Evaluate integrity indicator (percentage per integrity indicator value)
� Make a comparison table of transponders ADS-B performance (transmission rate, data), according to the transponder type (3 types of equipment)
Air Systems Division13
Trial configuration
One Thales AS680 ADS-B Ground Station installed on the airport surface� Not optimum location, antenna set on the ground and therefore visibility is
limited
� Raw data collection on Local Maintenance & Control System
� ADS-B Asterix Cat21 reports sent through telecom line to French DGAC facility, a few km away, and recorded there
� 3 MSSR (Thales) + 1 MSSR Mode S (Thales)
Airbus test aircraft + Opportunity flights
Duration of data recording : 9 months (May 05-January 06)Amount of collected data : >40Go (including ADS-B +radar data)
Air Systems Division14
Some results – Call Sign
0%
20%
40%
60%
80%
100%
AFR IBE RYR EZY SWR TAP BAW HLF TRA DLH
correlated callsign containingneither the ICAO code not the IATAcode of the airline
correlated callsign containing theairline IATA code
correlated callsign containing theairline ICAO code
More than 90% of Air France, Ryan Air, EasyJet , Swiss Air and DLH callsigns could be correlated to an existing flight plan. Comment: amongst the other airlines flying in Toulouse, lot of erroneous call sign (or no call sign at all) have been observed.
Air Systems Division15
Some results – NUC versus airline
0%
20%
40%
60%
80%
100%
AFR IBE RYR EZY SWR TAP BAW HLF TRA DLH
a/c with PA sometimes <5 andsometimes >= 5
a/c with PA = 0 always
a/c with PA >= 5 always
� More than 80% of Hapag Llyod (HLF), Ryan Air and Eas yJet aircraft
always report NUC (PA )>= 5.
� Conversely, more than 80% of Air France, Iberia and DLH aircraft always report NUC = 0.
Data collection in Toulouse, France : May 05 – Januar y 06
Air Systems Division16
Possible reasons for transmission of NUC = 0
Aircraft transmitting NUC always equal to 0 are not equipped with an appropriate architecture to receive GPS data (no GPS in the aircraft, no connection with a GPS engine or any other source for GPS data…)
The position data are coming from FMS or IRS, without integrity indicator (i.e. no GPS HPL)
Transmission of NUC = 0 is not an indication that the position is incorrect, but only an integrity indicator: “can I rely on the position of this aircraft?”
When aircraft airborne, the ground station is configured to automatically translate NUC < 5 to a PA=0 (I.e. discard the report)
When aircraft on ground, the ground station is configured to automatically translate NUC ≤ 6 to a PA=0 (I.e. discard the report)
Air Systems Division17
Opportunity Flights- Evaluation of integrity indicat or
46% of aircraft always report NUC =042% of aircraft always report NUC >512% of aircraft report both NUC >=5 and NUC < 5
What is the architecture of these aircraft?
A/C equipped with GPS
A/C whose transponder does not receive GPS data
ac with all NUC >= 5
42,0%
other12,0%
ac with all NUC = 046,0%
Note: a lot of aircraft reporting a NUC = 0 have, nevertheless, a very accurate navigation behaviour
Air Systems Division18
Observed Latency
On-board plus ground latency may reach 1.6s, in some instances.
Air Systems Division19
Theoretical max position Latency
GS reception
GS time stamping
ADS-B GS
Time
Position calculation
GPS sends position 1Hz
Around500 ms
IRS receives GPS position
IRS transmitsGPS position
500 ms
XPDR receives GPS position
XPDR extrapolatesposition
200 ms 10 msneg neg neg
GPS EngineMMR
Inertial Reference
System: IRS
ADS-B 1090 MHz Transponder
Air Systems Division20
Conclusions
This project:
� Allowed to collect large amount of air and ground data
� Was an opportunity to study avionics performance
� Provided data analysis to support airborne certification� It has been an input for European AMC-20-24
� Allowed to identify and analyse a number of issues such as onboard latency
Air Systems Division21
Hong-Kong - 2007
Air Systems Division22
Thales AS680 ADS-B Ground Station was mounted at th e Tai Mo Shan, which is the highest mountain in Hong Kong (a bout 1000 metres above mean sea level)
SSR Antenna
ADS-B Antenna
Trial set-up
Opportunity flights
Slide courtesy of Civil Aviation Department, Hong Kong, China
Air Systems Division23
Evaluation & Analysis
� Data was subsequently analyzed to determine� coverage achieved� aircraft detected
� flights detected� percentage of aircraft fitted with ADS-B
� percentage of good position data transmitted (average NUC > 5)
� Visual comparison of ADS-B tracks vs SSR’s� Displayed positions of ADS-B tracks and SSR’s� velocity vectors derived from ADS-B and SSR
Slide courtesy of Civil Aviation Department, Hong Kong, China
Air Systems Division24
Longest ADS-B track detected 290NM from Tai Mo Shan
The outer
range ring
is 250NM
Ground Station coverage (1)
Slide courtesy of Civil Aviation Department, Hong Kong, China
Air Systems Division25
108
110
112
114
116
118
120
122
15 17 19 21 23 25 27 29
100nm
200nm
250nm
Flight of oppurtunity coverage
Smoothed Oppurtunity Coverage
Note - Only targets of opportunity were used
Coverage Summary – 20000 Feet and Above
Coverage assessment
Slide courtesy of Civil Aviation Department, Hong Kong, China
Air Systems Division26
Note - Total not sum of days, as some aircraft detected on multiple days
Date
Number ofADS-B
EquippedAircraft
Number ofADS-B
Aircraft withNUC > 5
Percentage ofADS-B Aircraftwith NUC > 5
Number ofADS-B Aircraftwith NUC <= 5
Percentage ofADS-B Aircraftwith NUC <=5
Numberof ADS-BAircraft
withNUC = 0
Percentage ofADS-B Aircraftwith NUC = 0
5th April 475 321 67.58% 154 32.42% 72 15.16%6th April 449 302 67.26% 147 32.74% 64 14.25%7th April 517 322 62.28% 195 37.72% 88 17.02%8th April 522 318 60.92% 204 39.08% 91 17.43%9th April 518 335 64.67% 183 35.33% 85 16.41%10th April 513 311 60.62% 202 39.38% 91 17.74%11th April 521 382 73.32% 139 26.68% 85 16.31%TOTAL 1028 670 65.18% 358 34.82% 182 17.70%
ADS-B Detection Summary By Aircraft
Slide courtesy of Civil Aviation Department, Hong Kong, China
Air Systems Division27
Occasionally it was observed that an aircraft would broadcast multiple slightly different callsigns over the course of its flight.
Should coupling on callsigns be used, this changing callsign would cause problems to the ATC system
Mode S ID Callsign SSR Code- 3123
5146KLM888 5146
KLM888 0 5146
KLM888 7 5146
KLM888 E 5146
KLM888 F 5146
KLM888 H 5146
KLM888 J 5146
KLM888 N 5146
KLM888 S 5146
KLM888 U 5146
KLM888 W 5146
KLM888KL 5146
KLM8LM88 31235146
484058
Points of Interest – Changing Callsign
Slide courtesy of Civil Aviation Department, Hong Kong, China
Air Systems Division28
ADS-B velocity vector versus SSR
113.7264
113.7266
113.7268
113.727
113.7272
113.7274
113.7276
113.7278
113.728
22.2 22.205 22.21 22.215 22.22 22.225
ADS-B DetectionRadar Detection
ADS-B velocity vector appears much more accurate th an radar’s
Slide courtesy of Civil Aviation Department, Hong Kong, China
Air Systems Division29
Summary of results
� About 39% of aircraft were equipped with ADS-B capability
� Around 65% of these equipped aircraft were transmitting position data (NUC > 5)
� 18% of equipped aircraft were permanently transmitting NUC of “0”� Changing call signs transmitted by aircraft may potentially cause problems to
ATC system coupling
� In general, the ADS-B signal coverage at Tai Mo Shan can be up to 290NM at a certain altitude. Relocation of the ADS-B receiver to other site(s) will be considered to collect another set of data/observations
� Velocity vectors of ADS-B tracks are more accurate than Radar’s� Improved rate of ADS-B detections creates a more smooth track on sharp turns.
Slide courtesy of Civil Aviation Department, Hong Kong, China
Air Systems Division30
ADS-B trial in Natuna, Indonesia – 2007(DGAC Indonesia)
Air Systems Division31
Trial objectives
Trial objectives
� Coverage analysis� Equipage analysis� Navigational Uncertainty Category (NUC) analysis
� Probability of detection analysis� Call signs reported by ADS-B � Data sharing testing
Data Collection� 48 hr period from 12 March 2007 � A total of 472,598 ADS-B messages were received from 394 aircrafts.
Slide courtesy of CAA Singapore (in the scope of datasharing with Indonesia)
Air Systems Division32
Location of Natuna
L625
B58
4
M767
M72
2
G334
R22
3N
646
N89
1
P501
M759
G460
B219
N502
M751
Y331
L642
G464
M75
5
A334
R45
5
G580
N884
M761
M75
4
Y445
G21
9
L64 4
A585
A576
B338
B469
N563
L629
M768
B33
5/N
646
M77
1
B335
R325
P570
M77
2
G584 N892
N875
Y33
2A
224
L635
R20
8 W533
A457
A464
R461
B592
Y336
G46
6R
579
B470
B466
M76
3
L637
B348
M758
R469
R467
M753
G582
M765
W401
G579
M644
B583
B463
L644
L644
G46
6
N875
M751
B592
M759
M768
N884
L625
L644
B348
G579
N89
2
A464
A464
M753
L644
G580
N892
M761
N89
2 M758
R20
8
B466
M77
2
G460
R45
5
G580
G580
N892
M77
1
G334
M753
R20
8
N891
M77
2
N875
L644
N89
1
A464
G460
B348
M768
M765
M77
2
B33
5
L642
G334
L644
M767
G580
A576
A457
N891
M75
4
A457 M761
M767
N875
N875
B592
R325
B470
L629
M758
M765
G334
R22
3
B338
B592
N875
G580
B348
L642
M77
1
M77
1
R20
8
G579
M644
A585
A464
G582
A576
M72
2
L644
L625
G334
N884
M768
A464
N891
W53
3
G334
A457 R325
B592
A464
A464
R22
3
N892N875
M758
B469
A585
B348
L635
M758
N884
G580
B348
B348
R469
N875
B463
M767
G580
M758
A576 M761
L629
B58
4
B469
G460
M768
L644
M77
2
A457
R469
M644
M758
R20
8
B470
N884
B348
B348
L642
M751
M768
N891
M77
2
R325
B592
M761
A464
50 Nm
100 Nm
150 Nm
200 Nm
250 Nm
natuna250buffer.mxd 13 April 2007
Slide courtesy of CAA Singapore (in the scope of datasharing with Indonesia)
Air Systems Division33
L625
B58
4
M767
M72
2
G334
R2 2
3
N646
N89
1
P501
M759
G460
B219
N502
M751
Y331
L642
G464
M75
5
A334
R45
5
G580
N884
M761
M75
4
Y445
G21
9
L 64 4
A585
A576
B338
B469
N563
L629
M768
B33
5/N
646
M77
1
B335
R325
P570
M77
2
G584 N892
N875
Y33
2A
224
L635
R20
8 W533
A457
A464
R461
B592
Y336
G46
6R
579
B470
B466
M76
3
L637
B348
M758
R469
R467
M753
G582
M765
W401
G579
M644
B583
B463
L644
L644
G46
6
N875
M751
B592
M759
M768
N884
L625
L644
B348
G579
N89
2A464
A464
M753
L644
G580
N892
M761N
892 M758
R20
8
B466
M77
2
G460
R45
5
G580
G580
N892
M77
1
G334
M753
R20
8
N891
M77
2
N875
L644
N89
1
A464
G460
B348
M768
M765
M77
2
B33
5
L642
G334
L644
M767
G580
A576
A457
N891
M75
4
A457 M761
M767
N875
N875
B592
R325
B470
L629
M758
M765
G334
R2 2
3
B338
B592
N875G580
B348
L642
M77
1
M77
1
R20
8
G579
M644
A585
A464
G582
A576
M72
2
L644
L625
G334
N884
M768
A464
N891
W53
3
G334
A457 R325
B592
A464
A464
R22
3
N892N875
M758
B469
A585
B348
L635
M758
N884
G580
B348
B348
R469
N875
B463
M767
G580
M758
A576 M761
L629
B58
4
B469
G460
M768
L644
M77
2
A457
R469
M644
M758
R20
8
B470
N884
B348
B348L6
42
M751
M768N891
M77
2
R325
B592
M761
A464
50 Nm
100 Nm
150 Nm
200 Nm
250 Nm
natuna250buffer.mxd 13 April 2007
200 Nm
250 Nm
9
2410
5
9
11
3
2 8
Slide courtesy of CAA Singapore (in the scope of datasharing with Indonesia)
Air Systems Division34
Location of ADS-B antenna
Slide courtesy of CAA Singapore (in the scope of datasharing with Indonesia)
Air Systems Division35
Equipage analysis
Total flights over the area: 911
Total flights recorded by ADS-B: 394
Percentage equipage: 43%
Slide courtesy of CAA Singapore (in the scope of datasharing with Indonesia)
Air Systems Division36
Probability of detection analysis
0.57
0.70.74 0.72
0.67
0.78 0.79
0.46
0.23
0.79 0.78
0.43
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
L642 M771 N892 L625 N884 M767 M758 M761 M772 L644 B348 G580
Air routes
Pro
babi
lity
of D
etec
tion
Slide courtesy of CAA Singapore (in the scope of datasharing with Indonesia)
Air Systems Division37
L625
B58
4
M767
M72
2
G334
R2 2
3
N646
N89
1
P501
M759
G460
B219
N502
M751
Y331
L642
G464
M75
5
A334
R45
5
G580
N884
M761
M75
4
Y445
G21
9
L644
A585
A576
B338
B469
N563
L629
M768
B33
5/N
646
M77
1
B335
R325
P570
M77
2
G584 N892
N875
Y33
2A
224
L635
R20
8 W533
A457
A464
R461
B592
Y336
G46
6R
579
B470
B466
M76
3
L637
B348
M758
R469
R467
M753
G582
M765
W401
G579
M644
B583
B463
L644
L644
G46
6
N875
M751
B592
M759
M768
N884
L625
L644
B348
G579
N89
2A464
A464
M753
L644
G580
N892
M761N
892 M758
R20
8
B466
M77
2
G460
R45
5
G580
G580
N892
M77
1
G334
M753
R20
8
N891
M77
2
N875
L644
N89
1
A464
G460
B348
M768
M765
M77
2
B33
5
L642
G334
L644
M767
G580
A576
A457
N891
M75
4
A457 M761
M767
N875
N875
B592
R325
B470
L629
M758
M765
G334
R2 2
3
B338
B592
N875G580
B348
L642
M77
1
M77
1
R20
8
G579
M644
A585
A464
G582
A576
M72
2
L644
L625
G334
N884
M768
A464
N891
W53
3
G334
A457 R325
B592
A464
A464
R22
3
N892N875
M758
B469
A585
B348
L635
M758
N884
G580
B348
B348
R469
N875
B463
M767
G580
M758
A576 M761
L629
B58
4
B469
G460
M768
L644
M77
2
A457
R469
M644
M758
R20
8
B470
N884
B348
B348L6
42
M751
M768N891
M77
2
R325
B592
M761
A464
50 Nm
100 Nm
150 Nm
200 Nm
250 Nm
natuna250buffer.mxd 13 April 2007
0.57L642
0.79L644
0.74N892
0.72L625
0.67N884
0.78M767
0.79M758
0.78B348
0.43G580
0.23M772
0.46M761
44
0.7M771
Slide courtesy of CAA Singapore (in the scope of datasharing with Indonesia)
Air Systems Division38
ADS-B reported call sign
47 out of 394 flights reported wrong call-signPossible reasons:
� Pilots/crew forgot to enter callsign;
� Pilots/crew made mistakes when keying callsign;
� Confusion over IATA and ICAO callsigns.
Slide courtesy of CAA Singapore (in the scope of datasharing with Indonesia)
Air Systems Division39
ADS-B reported call sign
Actual CallsignFLRoute24-bit codeCallsign
SLK924340M77176CD89MI924
MAS390360 - 380M77175005DMH390
PAL503360M767758064PR503
AXM5255280M758750129AK5255
CCA958360M771780291CA958
AXM5254270M758750129AK5254
GIA896400M7718A0037GA896
CEB804360N88475805F5J804
CEB548380N88475804B5J548
KAL367360N89271BE00KAL0367
KAL353360N89271BC99KAL0353
CEB803360M76775805F5J803
CEB547360M76775804B5J547
CXA852360M7717BB136852
AXM5108370M758750106AK5108
AXM5156370M758750105AK5156
EVA6207390N89289904F-
Slide courtesy of CAA Singapore (in the scope of datasharing with Indonesia)
Air Systems Division40
Summary of results
Results could support the use of ADS-B for ATC operation on the 6 parallel RNP-10 routes of the South China Sea
Coverage can be further improved by adding or relocating ADS-B sensors.
Pilots/crew should be instructed to key in ICAO call signs.
Slide courtesy of CAA Singapore (in the scope of datasharing with Indonesia)
Air Systems Division41
Conclusion
Air Systems Division42
Trials set-up in various plaes of the world allowed to assess the overall performances of ADS-B:
� Percentage of aircraft equipped
� Percentage of aircraft broadcasting correct ADS-B d ata
� Measurement of update rate, NUC distribution
� Analysis of Call Sign correctness
In addition ADS-B trials represent an opportunity f or testing across FIR data sharing, which definitely can enhan ce safety and efficiency.
As already achieved in Europe and Asia, Thales is r eady to support CAAs of Latin America for the preparation o f ADS-B trials.
Air Systems Division
Thank You
Ludmilla GonzalesBusiness Development Manager
[email protected] : +33 (0)1 79 61 42 57
Mob : +33 (0)6 75 79 90 09
Air Systems Division44
Horizontal Protection Level
GPS
Calculate HPL
ADS-BTRANSPONDER
POSITION
HPLPOSITION
NUC (derived from HPL)
ADS-B GROUND STATION
ATC SYSTEMPOSITION
PA
GPS receiver calculates Horizontal Protection Level (HPL) which is the radius of
the circle within which it is almost sure (1 - 10-7) to have the true position
The transponder encodes HPL into
NUC (less bits)
ATC System checks the NUC
(PA) value before using the position
data
When included in Asterix Cat 21 report, the NUC is called PA (position accuracy)
Air Systems Division45
Figure Of Merit
Figure Of Merit (FOM) represents the accuracy of the position measurement by the GPS receiver
This term is sometimes incorrectly used to designate NUC or PA (=> bringsconfusion)
In the updated version of tranpsonder standard (i.e. DO260A), NUC has been replaced by 3 parameters:� NIC (Navigation Integrity category) <-> HPL
� NAC (Navigation Accuracy Category) <-> FOM� SIL (System Integrity Level) : related to airborne configuration, indicates the
level of Integrity (i.e. 10-7, 10-5 or 10-3)
Air Systems Division46
Definition Of NUC