ADS-B Technical Issue

The CASCADE Programme

General Aviation ADS-B Workshop

ADS-B Technical Issues

C. TamvaclisEUROCONTROL Experimental Centre

European Organisation for the Safety of Air Navigation

Content

ADS-B system requirements

ADS-B infrastructure

Equipment availability and certification

Safety and Performance issues

Interoperability issues

Equipment developments

Final remarks

ADS-B System Requirements

[ADS-B OUT] Aircraft must broadcast at least 2-D position, barometric altitude, and flight identification

with prescribed characteristics specified in aviation standards integrity, latency, accuracy, continuity, availability …

and including position integrity indication

[ADS-B IN] Ground and airborne ADS-B receivers must report targets within prescribed coverage volumes and with adequate update periods

suitable surveillance data processing and display systems are also neededcoverage and update rates are application dependent

Air to ground and air to air broadcast datalinkfor global interoperability 1090 MHz Extended Squitter (1090ES)

locally VDL-4 and/or UAT may also be used

minimum aircraft equipageADS-B OUT

1090ES capable Mode S transponderGNSS receiver and baro altimeter

ADS-B IN1090ES receiverCockpit Display of Traffic Information (CDTI)

minimum ground equipageOne or more 1090ES ground receivers [stations][surveillance data processing system]

for tracking and fusion with other surveillance data

situation display

ADS-B Infrastructure

1090ES ADS-B OUT System

Mode STransponderGPS

PositionHFOM

(VFOM)HPL

(VPL)Time

Extended Squitter

IdentityPosition

NUCVelocity

BarometricAltimeter

FL

24-bit address

TransponderControl Panel

Callsign SPI-EI

1090ES ADS-B IN System

Mode SReceiverGPS

Own PositionHFOM

(VFOM)HPL

(VPL)Time

BarometricAltimeter

FL

24-bit address

CDTI

Ext. Squitter

IdentityPosition

NUC(Velocity)

ADS-B Validation Testbed

ATCC simulator

CWPFPPS

Radars

ADS-B GS

Flight plans

Cockpit

ADSP

ADS-B Network

ADS-B reports

AST cat 21

A/C Sim

Trackertracks

AST cat 62

plots

ADS-B reports AST cat 21

TIS-B

Server

Aircraft Traffic Generator

+recording replays

Airborne Tracker

ADS-B Server

TIS-B GS

Link Error Emulator

RMCDE

ACAS

All ADS-B system components are commercially availableEquipment and installation need to be certified for ops useAircraft equipment:

Mode S Transponder: 1090ES potentially a software upgrade on newer transponder models, certified to

RTCA MOPS 260/A and FAA TSO C166EUROCAE ED73B/102 and EASA ETSO 2C112b

1090ES Receiver: Few products in the market, standalone or combined with TCAS

RTCA MOPS 260/A and FAA TSO C166

GNSS Receiver: Pre 2003 GPS receivers may not provide integrity signalling. Required certification:

FAA TSO C129a (RAIM), C145/146 (SBAS), C161 (GBAS)

CDTI: Some products in the market but no certification available

Equipment availability and certification

Safety and Performance Issues

Requirements under development by the Requirements Focus Group (RFG)

ED-126 will address ADS-B surveillance in non radar airspaces

The current 1090ES system has been designed to meet requirements in the RTCA MASPS [DO-242/A]

therefore current MOPS may need to be updated in the future

Quality of ADS-B installation onboard the aircraft is critical need for reliable indication of position integrity and low latency

CDTI is critical for airborne surveillance applications [ADS-B IN]requirements are not agreed as yet

Need for airborne tracking function?HMI factors and placement in cockpit

Interoperability Issues

Multiplicity of 1090ES standards FAA standardizing on DO-260A while existing equipage is mostly DO-260

DO-260A is backwards compatible with DO-260RTCA recently published DO -260/A Change 1

need for features added in RTCA DO-260A has to be clarified [RFG work]

1090 MHz Band availabilityADS-B over 1090ES operates in the same RF Band as SSR, Mode S, and TCAS/ACASinterference could become a problem in Core Europe

ADS-B IN will be affected firstThere are mitigations

SSR upgrade to Mode S, replacement by ADS-B and more sophisticated ADS-B receivers.

Equipment Developments

The CASCADE Programme is sponsoring development of airborne and ground equipment needed for its ADS-B validation activities

ADS-B and TIS-B ground station [Thales ATM]ADS-B system Oct 06

TIS-B system April 07Airborne 1090ES ADS-B/TIS-B Receiver [ Selex Communications]

delivery May 07CDTI [Selex Communications/EUROTELEMATIC]

delivery Dec 06Usable for air traffic situation awareness applications

for general and business aviation aircraft

Final remarks

ADS-B OUT over 1090ES can be implemented today existing GPS and Mode S aircraft installations may be upgradeable to ADS-B, need for ADS-B equipment and installation airworthiness approval

ADS-B IN lacks CDTI standards and airworthiness certificationAir Traffic Situation Awareness standards in development [RFG]

There are many ADS-B equipment developments targeting General Aviation, for example:

low power and light weight 1090ES systems a “light” transponder standard is in development

integrated systems:1090ES transponder and receiverGPS and CDTI