1

Communication Systems

<< General >>

Datalink Network

Aeronautical Telecommunication Network

<< Air/Ground Communication >>

Air/Ground Datalink Application

VHF Digital Link

VDL Mode-2 transition

HF Data Link

AMSS

Gatelink

<< Ground/Ground Communication >>

AIDC

AMHS

<< Service >>

AIS

PDCS

D-FIS / D-ATIS / D-VOLMET

<< Other >>

CBB

SwiftBroadband

2

Communication Datalink Network

ACARS ATN Broadband IP

Widely used today In development 1992

Slow acceptance by aviation community

Dominant in grounds network

Implemented for cabin, but not for

cockpit

Approved by aviation industry Approved by aviation industry Under negotiation

Low bandwidth Moderate bandwidth Hi bandwidth

Dedicated to aeronautical

communications

Dedicated to aeronautical

communications

Common network using COTS device

makes cost reduced

IP Standards and requirements not

matured

VHF HF SATCOM Broadband Gatelink

Rate 2.4kbps (POA)

31.5kbps (VDL2)

1.8kbps 0.6kbps – 10.5kbps - 432kbps

10 - 40Mbps

384kbps – 50Mbps

Coverage Continental Continental

Oceanic

Polar

Continental

Oceanic

Continental

Oceanic

Airport

Datalink Network

Datalink Media

Broadband

Generally refers to a user access network connection with bandwidth approximately 1 Mbps or more. It is essential for graphic-

intensive websites, music services and video applications. Common forms of broadband include DSL (Digital Subscriber Line),

cable modem, WiFi (wireless access), and Metro Ethernet (Ethernet access over optical fiber).

Overview

3

Communication ATN (Aeronautical Telecommunication Network)

ATN is a global inter-network that will provide for

digital communications between ground users, and

aircraft.

ATN provides the data communication required to

support the distributed ATM automation system.

Compared to conventional voice communication

systems, the ATN and its ATM applications offer the

following benefits:

•better clarity of communications resulting in reduced

transmission and/or interpretation errors;

•more efficient use of communication channels

resulting in less air-ground radio channels and less

dedicated lines on the ground;

•possibility of connecting any two-end users

(airborne or ground-based) in a global data

communication network environment;

•reduced workload for pilots, controllers and other

personnel involved in ATM due to the availability of a

variety of pre-formatted and stored messages; and

•reduced requirements for multitude of

communication systems by accommodating ATSC,

AOC, AAC and APC.

•ATN Ground-to-ground applications include AMHS

(ATS Message Handling System) and AIDC (Air

Traffic Inter-facility Data Communications)

Air/Ground Subnetworks

•AMSS

•VHF Digital Link

•SSR Mode S Data Link

•HF Datalink

Airborne Subnetworks

•Avionics (AES)

Ground/Ground Subnetworks

•LANs (Ethernet, Token Ring, FDDI, etc.)

•WANs (X.25, Frame Relay, ATM, ISDN)

Overview

Sample Configurations

4

SARPs for the ATN were included in the ICAO Annex 10, Volume III,

Part 1, Chapter 3 (Aeronautical Telecommunication Network),

introduced as part of Amendment 73 to Annex 10, applicable with effect

from November 1998.

The initial ATS to be offered by the ATN, i.e. Controller Pilot Data Link

(CPDLC) and ADS relieve R/T congestion and provide accurate and

timely surveillance information in remote and oceanic regions. The

result of these services will reduce controller workload and

correspondingly increase capacity and safety levels

In 2002, ARINC installed and deployed thirteen VDL Mode 2 ground

stations to provide coverage for the US FAA’s CPDLC Build 1

programme in the Miami Air Route Traffic Control Center (ARTCC). The

associated infrastructure included redundant ATN air-ground and

ground-ground routers. Deployment of VDL Mode 2 (in an ATN

environment) by ARINC was planned in Europe for the operational use

of CPDLC at the Maastricht Upper Area Control Center (UACC) .

Further deployment was also foreseen in Japan.

Communication (A/G) Air/Ground Data Link Applications

Voice radio messages between pilots and air traffic controllers

are exchanged continuously. The Controller-Pilot Data Link

Communications (CPDLC) system reduces the number of

voice messages by using a special electronic link for routine

messages. These messages are digitally displayed on a

computer screen in the cockpit. Shifting routine transmissions

from voice to data link communications frees up voice

frequencies and reduces delays.

http://usrwww.mpx.com.au/~cjr/CPDLC.htm

DATA DATA

ATM CENTER GES

DATA

Overview International Activities

5

Communication (A/G) ARINC/ATN Standards on OSI Model

Overview

The following table shows OSI model vs ATN/ARINC standards.

☆　Character-oriented protocol ⇒ACARS　　　　　　 　　　　　　★　Bit-oriented protocol⇒ATN 　

PDU n

PH(SYN)

PDU m

8-bit ASCII character （character only） Arbitrary sized bit fields　（bit stream）

0100011101010-AHDYUOJ377KIHFL735- 01111110

6

Communication (A/G) ACARS Standards

Overview

The following table shows structure of ACARS systems.

AOC / ATS Application

(ARINC622,623)

AEEC 620 ACARS Protocol

Air/Ground Routing Protocol

VHF

(ARINC 618)

AMSS

(ARINC 618)

AEEC 620 ACARS Protocol

Label/SMI Conversion

Air/Ground Routing Protocol

AMSS

(ARINC 618)

VHF

(ARINC 618)

AEEC 620 ACARS Protocol

AEEC 620 TEI Processing

IATA Standard Message Text

(BATAP)

IATA SMT

(BATAP)

TEI Processing

SDU

(ARINC741) GES

(Inmarsat SDM)

VHF Radio

(ARINC716) VHF Radio Station Teletype

Router

AOC / ATS Application

(ARINC622,623)

Data network

Node (X.25)

Data network

Node (X.25)

AMSS Data2

VHF

ACARS Management Unit Datalink Service Processor User Ground System

Air to Ground formats Type-B formats

Airborne Systems Datalink Provider Airline Host Computer

7

Communication (A/G) VDL (VHF Digital Link)

Data communication system to overcome the capability limit of

ACARS; faster, more reliable and more flexible, can send

graphic data as well as characters. Carrier Sense Multiple

Access with 31.5kbps speed.

Data-only ＶＤＬ

Flight Information・・・

WX Information Graphics

Data･･･

Data

communication

VDL Mode 2

Voice

JA×××

MAINTAIN 120

・・・・・・

CPDLC

Flight Information

WX Information

Graphics Data

A B C D A B C D Voice Data Data Voice

VDL Mode 3

Security assurance by digital voice for ATC, efficient frequency

use by sharing channels among multiple users. Time Division

Multiple Access with 31.5 kbps.

Originally developed as air-ground link for ADS-B, but can serve for

point-to-point communication. Self-organizing Time Division Multiple

Access with 19.2 kbps.

VDL Mode 4

1996: technical specifications relating to the RF characteristics for VDL;

1997: SARPs and guidance material for VHF digital link (VDL-Mode 2);

2001: integrated voice and data link system (VDL Mode 3); and data

link satisfying surveillance applications (VDL Mode 4);

Overview

International Activities

CSMANo time critical

31.5kbps

D8PSK

ACARS

Data com

Mode-2（ARINC/SITA）

STDMATime critical

TDMATime critical

Media access scheme

19.5kbps4.8kbps×4　(31.5kbps)

Bit rate

D8PSK/GFSKD8PCKAnalogModulation scheme

NoneRCAG/RAGVHF comRelation with existing system

ADS-B (Data com)

Voice/Dat（2V2D/4V ）

Voice comApplication

Mode-4（Euro/Russia）

Mode-3（Selected FAA）

8.33kHz Separation

VDL Type

CSMANo time critical

31.5kbps

D8PSK

ACARS

Data com

Mode-2（ARINC/SITA）

STDMATime critical

TDMATime critical

Media access scheme

19.5kbps4.8kbps×4　(31.5kbps)

Bit rate

D8PSK/GFSKD8PCKAnalogModulation scheme

NoneRCAG/RAGVHF comRelation with existing system

ADS-B (Data com)

Voice/Dat（2V2D/4V ）

Voice comApplication

Mode-4（Euro/Russia）

Mode-3（Selected FAA）

8.33kHz Separation

VDL Type

8

Communication (A/G) VDL Mode-2 transition

ACARS (POA)

VDL-Mode2 (AOA)

VDL-Mode2 (ATN)

Character-oriented data communication

between aircraft systems and ground systems

(Plain Old ACARS). ). The mode of transmitting

the analog signal to legacy ground stations is

Minimum Shift Keying (MSK), operating at

2.4KHz.

ARINC758 CMU ARINC750 Radio

ARINC 429

Signal (AOA)

To Digital VHF Network

Digital D8PSK

ARINC758 CMU ARINC716 Radio

Audio Signal

(POA)

To Analog VHF Network

Analog MSK Signal

ARINC758 CMU ARINC750 Radio

ARINC 429

Signal (AOA)

To ATN

Digital D8PSK

ACARS messages and routing over VDL Mode

2 air/ground data link (D8PSK). The

transmission mode is now Differential 8 Phase

Shift Keying, operating at 31.5 KHz. Higher

level message formats are identical to POA

without any changes to the airborne and ground

application.

BIT-oriented communications, OSI model,

dissimilar data links. End to end support of VDL

mode 2 in an ATN environment

There is step by step action to implement VDL-Mode2. The followings are reasons why interim action is required for ATN/VDL Mode-2:

・VHF ACARS network saturation in the high density airspace of Europe and the USA could be resolved by the use of VDL which

provides 10-20 times more capacity per channel.

・ATN implementation in aircraft will be facilitated by the prior installation of CMU/VDR architecture.

・An interim VDL implementation in avionics justifies the deployment of a network of VDL ground stations which are ready to support

ATN service.

・An Interim VDL implementation will provide experience of VDL use of the VHF band which is needed to plan for a system to support

ATC datalink.

Overview

9

Communication (A/G) VDL Mode-2 transition

Data Communication

Network

ATN AoA ACARS(POA)

ATN System ACARS Host ACARS DSP

VHF

Ground

Station

Remote

Ground

Station

AVLC link AVLC link

ATN User Traffic

ACARS User Traffic

POA:Plain

Old

ACARS

AoA:ACARS

over

AVLC

AVLC:Aviation

Link

Control

ACARS

Coverage

AoA:ATN

Coverage

ACARS/VDL Communication Connection

10

Communication (A/G) HFDL (HF Data Link)

Amendment 74 (1999) to the Annex 10 introduced the SARPs for HF

data link.

ARINC initiated service of its SARPs-compliant HFDL system in

January 1998. During 2003, 14 geographically diverse HFDL ground

stations, transmitting on 30 active frequencies, provided near global

(exception:Antarctica) A/G data link coverage. An adaptive frequency

management program changed the active frequencies at each site in

response to atmospheric conditions, such as day-night temperature

changes and ionospheric anomalies, to achieve optimum propagation

and to avoid interference with nearby HFDL ground stations or HF

voice stations. ARINC will expand site configurations as required by

equipage and usage growth.

HFDL coverage provides a uniquely cost-effective data link

capability for carriers on remote oceanic routes, as well as the

polar routes where SATCOM coverage does not reach. HFDL

avionics are much lower in cost than SATCOM, and many

carriers use HFDL instead of satellite services, or as a backup

system. HFDL is still the only data link technology that works

over the north pole area above 80deg, providing continuous,

uninterrupted data link coverage on the popular polar routes

between north America and eastern Europe and Asia.

Transmissions on HF are in USB on a sub carrier of 1440 Hz

with a symbol speed of 1800 baud. Modulation is 2-PSK, 4-PSK

or 8-PSK with effective bit rates of 300, 600, 1200 or 1800

bits/sec. The HFDL service is operated by ARINC as

GLOBALink service through a worldwide network of HF stations.

Overview International Activities

11

Voice and data link communication between aircraft and ATC

using satellites enables reliable and high quality

communication in oceanic airspace.

Satellite 1 Satellite 2

Center 1 Center

2 ATM

Center

Amendment 70 (applicable: 1995) for Annex 10 introduced SARPs

for the aeronautical mobile-satellite service (AMSS).

Then, Amendment 75 (2000) specified changes to the AMSS

SARPs introducing a new antenna type, a new voice channel type

and enhanced provisions for interoperability among AMSS systems

The AMSS function of Japan’s MTSAT system is fully compliant

with the AMSS SARPs and fully supported all types of aeronautical

communications defined by ICAO. JCAB had signed an operational

agreement with Inmarsat, which is providing AMSS services

worldwide, in order to assure full interoperability between MTSAT

and the Inmarsat system. The aircraft earth station (AES) currently

operating in the Inmarsat system would be able to use the MTSAT

system without any modification to aircraft systems by simply

adding MTSAT data to their satellite data unit (SDU).

AMSS ( Aeronautical Mobile Satellite Service ) Communication (A/G)

Overview International Activities

12

Communication (A/G) Gatelink

Wireless gatelink is a system that utilizes Wireless Local Area

Network (WLAN) technology to transmit data throughout an

airport environment, enabling instant sharing of data between

aircraft, passenger terminals, maintenance operations,

baggage handling, ground-support equipment and more. Such

instant sharing of data would help airlines to increase

operational efficiency and improve on-time performance.

Getelink can provide 384kbps – 50Mbps data to airplane

around airport. This can enable the systems that require hi

speed data network as like EFB.

The definition of an Electronic Flight Bag (EFB), according to

the FAA's Advisory Circular (AC No. 120-76A), is an electronic

display system intended primarily for cockpit / flightdeck or

cabin use. EFB devices can display a variety of aviation data

or perform basic calculations (e.g., weather, performance data,

fuel calculations,etc.). In the past, some of these functions

were traditionally accomplished using paper references or

were based on data provided to the flight crew by an airline's

"flight dispatch" function. In short, an EFB is an electronic

information management device that helps flight crews

perform flight management tasks more easily and efficiently, in

a less-paper environment.

A "wireless gate link" system was trialed by Boeing at Changi

airport. It is essentially a wireless digital link between an

airport terminal building and an aircraft on the tarmac which is

capable of transmitting airline operations data. Changi Airport

is among the world's first commercial airports to be equipped

with a working wireless gate link system. This will offer cutting-

edge services to airlines, significantly strengthening

Singapore's position as a global air hub.

Electronic Flight Bag

Overview International Activities

13

The AIDC(ATS Interfacility Data Communications) provides a means of exchanging operational air traffic control flight information

between ATS Units via ground/ground data link. The AIDC application automatically exchanges ATC information between ATSU in

support of the ATC functions relating to NOTIFICATION of flights approaching an FIR boundary, CO-ORDINATION of boundary

crossing conditions, and TRANSFER of control at the FIR boundary. AIDC services reduce the workload of air traffic controllers.

Reference - http://www.icao.int/icao/en/ro/apac/attf3/pres_atns3-2.pdf

Communication (G/G) AIDC (ATS Interfacility Data Communications)

In accordance with Decision of APANPIRG/13, the AIDC Task Force was reconvened to re-examine and update the ASIA/PAC ICD for AIDC

(based on AFTN) published in June 1995 in order to allow States implement their systems in a consistent manner. The Review Task Force

meeting, was held in Brisbane in March 2003, in which the following items were discussed,

• AIDC message set

• Message sequences

• Each elements of message set

The Asia/Pacific AIDC ICD version 2 was published on 28 March 2003.

Notify Phase Coordinate Phase Transfer Phase

Overview

International Activities

14

AMHS (ATS Message Handling System )

ATS Message Handling System (AMHS) is designed to process

ATS messages including Flight Plan, NOTAM, etc, based on ISO

MHS Standard over the ATN Internet.

AMHS will only process messages to it end user of its domain.

AMHS also perform as a gateway for AFTN/CIDIN as required

ATS Message Handling System (AMHS) is the Message

Handling System (MHS) for Air Traffic Control, which is running

X.400 protocol with ATS Message Server, ATS Message User

Agent, and AFTN/AMHS Gateway or CIDIN/AMHS.

The ATS Message Service, which is a store-and-forward

messaging service over the ATN Internet

The ATN Pass-Through Service, which is a transmission

facility over the ATN Internet for AFTN (Aeronautical Fixed

Telecommunication Network) messages.

Basic ATS Message Service

Meets the Basic requirements of the first version of the Message

Handling Systems (MHS) Profiles published by ISO, and additional

features to support the AFTN service

Extended ATS Message Service

Provides several functionalities in addition to those of the Basic

ATS Message Service

The ATN Pass-Through Service encapsulates and

decapsulates AFTN messages at an AFTN/ATN type A

Gateway.

ATN/AMHS service

Communication (G/G)

Overview

US

FJ

AU

JP

HK

CN

TH

TW

KR

VN

PH

BN MY

IN

LA

KH

MM

ATN Backbone Site

ATN Site

ID

LK

BD

MN

SG

Ground/Ground network configuration in Asia

15

AIS Enhancement

Concept

Communication (service)

Overview

Sample Configurations

The Air Traffic Management (ATM) environment has evolved

over the last forty years from a mainly procedural based

system in which aircraft is navigated by the specific radio

navigation facilities to an RNAV based system with radar

coverage.

The process of evolution has been enabled by the introduction

of automated air and ground systems and their associated

databases. Progressively, the systems have depended

on the availability and reliability of digital navigation

databases which are assembled by data derived from

appropriate paper-based aeronautical information

publications (AIP) and associated documentation.

The role and function of aeronautical information has been

changing significantly.

With advancement of these changes, the amendments of

ANNEX4, ANNEX15 regarding to the following issues

have been commenced.

・Introduce Quality Systems for AIS

・establish Static Data base and exchange data world wide.

・Digital terrain data, obstacle data and airport mapping data.

・e-AIP

・introduce GIS technology for AIS

It is planned, between North American and European

Regions, to commence the exchange of aeronautical static data

from 2006.

Asia/Pacific Region should correspond to such developments.

Non-fixed

FormRAW DATA

SOURCE

RAW DATA

SOURCE

Fixed form

AIS CENTER

Receive

Format

Check

Register and Issue

Static Data

AIS

Data Base

RAW DATA

Edit Static Data

STATIC

DATA e-Chart WORK FILE

Edit and Issue e-Chart

ARIN424

Users

Edit and Issue e-AIP

e-Chart

e-AIP

e-AIP・e-Chart

Retriev

e

Retrieve

OBSTACLE DATA

MAP/TERRAIN

Static Data management functionStatic Data management function

ee--Chart management functionChart management function

ee--AIP managementAIP management

functionfunction

Product management functionProduct management function

AIXM

Retrieve

Other Countries

STATIC DATA

WORK FILE

Quality system

Provide

Provide Exchange

Electronic AIP

• Truly Electronic version of AIP

• Based upon XML technology

• Web/CD-ROM/Paper/.. distribution

• Fully ICAO compliant

• Independent of local systems(DB, Word Processors)

• Uniformity in structure, content & presentation

Obstruction

Database

Airport

Database

Terrain

Database

Aircraft

Reference

ELECTRONIC TERRAIN

AND OBSTACLE DATA

(ICAO ANNEX15 CHAPTER10)

16

Communication (service) D-FIS (D-ATIS・D-VOLMET)

From flight, runway and taxiway instructions, to information on

avionics equipment, frequency outages, NOTAM and local

weather conditions including VOLMET, pilots can obtain

FIS/AIS/NOTAM/VOLMET messages worldwide with high

reliability, at any time, using Datalink Information Service that

include D-FIS, D-ATIS and D-VOLMET.

Here's benefits aviation stakeholders can receive:

•Aircrew—With reliable, accurate delivery of messages via

digital data link, the aircrew no longer needs to find an open

voice channel and manually transcribe routine information.

Pilots can download and save D-FIS / D-ATIS / D-VOLMET

messages at any time during the flight, opening up the critical

approach phase for more important tasks.

•Airlines—Early departure messages mean fewer delays and

improved airline efficiency.

•Passengers—Reduced aircrew workloads and fewer delays

mean more traveler convenience.

•Air Traffic Service Providers—Compatible format means

ATSPs can have their D-FIS / D-ATIS / D-VOLMET messages

received by aircraft around the world, regardless of the

installed avionics.

•Airline Operations Centers—AOCs can compile regularly

delivered messages used in dispatching flight operations, as

well as in prioritizing and planning ahead.

•Air Traffic Controllers—Advanced D-FIS / D-ATIS / D-

VOLMET workstations allow controllers to quickly generate

and update messages on airports and routes status and

weather conditions.

Already available at many world's busiest airports and in use by

hundreds of the airlines, D-FIS / D-ATIS / D-VOLMET allows pilots

to receive and read text messages using the aircraft's existing

display format via data link service.

D-ATIS

D-FIS

D-VOLMET D-FIS

D-VOLMET

RCAG

Airport

Overview International Activities

17

Communication (Service) PDCs (Pre-departure clearances)

PDC delivery over data link was available at 57 airports in the U.S. in

April 2001 according to ARINC.

In Australia, pre-departure clearances are automatically formatted by

TAAATS and sent over the data communications networks to airline

flight operations computers or duty controllers in the flight operations

centre.

China started operations at Hong Kong International Airport on the pre-

departure clearance (PDC) delivery to aircraft via data link. Aircraft

equipped with the appropriate aircraft communications addressing and

reporting system (ACARS) and the required software can access and

receive the full script of PDC messages. China is considering to extend

PDC delivery services via data link to other major airports in China.

Getting an IFR route clearance has often been difficult during

busy times at major airports, with pilots competing on a

congested clearance delivery frequency, and controllers

having to read involved, often lengthy instructions. The Pre-

Departure Clearance System transmits to flight crews, via

data link, Air Traffic Control information on pre-departure

clearance. The system eliminates the need for voice contact

between the flight crew and the tower and can relieve the

congestion on the ATC tower clearance delivery frequency

that causes much of the delay at busy airports.

datalink

Overview International Activities

18

Communication(Other) CBB (Connexion by Boeing)

Connexion by Boeing gives you high-speed Internet access while you're traveling. Our network speeds are comparable to a modern home

or office environment. Connexion by Boeing provides the following service.

・Send and receive E-mail

・Browse the Internet

・Access your Company Intranet

・4ch Television

http://www.connexionbyboeing.com/index.cfm?p=cbb.aboutservice&l=en.US&ec=&cfaq=cs&e=#e4

CBB is the service mainly focus on AAC and APC, and

not focus on ATC so far. However, Connexion by

Boeing provides hi speed connection service, so pilot

can be possible to acquire the large size of information

as like Weather Map that is impossible to send by

ACARS . In the future, it might be possible to use hi

speed data service on ATS through CBB.

Connexion by Boeing is already available by some

airline including Singapore Airline, JAL, ANA, etc…

ConneXion by Boeing

Overview

19

SwiftBroadband (BGAN) by INMARSAT-4

The first of three new generation Inmarsat-4 satellites is successfully launched on May 28, 2005. Inmarsat-4 will provides BGAN which is

an IP and circuit-switched service that will offer voice telephony and a sophisticated range of high-bandwidth services, including internet

access, videoconferencing, LAN and other services, at speeds of up to 432kbit/s. Compared with an Inmarsat-3 satellite, the Inmarsat-4

boasts 60 times more power, 25 times the receiver sensitivity, 16 times the capacity and 12 times greater efficiency in its use of radio

spectrum.

In terms of passenger connectivity, BGAN is expected to deliver cost improvements for existing offerings such as laptop e-mail and

SMS/seat-back e-mail, while enabling new services such as VPN and access to corporate intranets, web browsing and GSM services.

BGAN will also deliver further enhancements for operational applications, enabling airlines to continue integrating aircraft systems into the

overall IT environment. It might include not only AOC, APC, ACC, but also ATC.

Inmarsat currently intends to launch a second I-4 satellite in the third quarter of 2005, which will be located over the Atlantic Ocean at

53ºW and provide service for the Americas. The two I-4 satellites will then cover 85 percent of the world's land mass. If two Inmarsat-4

satellites is successfully launched, another Inmarsat-4 satellite may cover pacific ocean area.

When the two satellites are fully operational, currently

expected in the fourth quarter of 2005, Inmarsat intends

to launch its new Broadband Global Area Network

(BGAN) service.

Communication(Other)

Overview

20

Navigation Navigation System

Overview of GNSS

Airborne Based Augmentation System (ABAS)

Satellite Based Augmentation System (SBAS)

Ground Based Augmentation System (GBAS)

RNP RNAV

RNAV Approach

WGS-84

RAIM

21

Navigation Overview of GNSS

(The Global Navigation Satellite System)

GNSS is the navigation system described in ICAO SARPs. It

consists of the following:

(1) Core Satellite positioning systems that combine trigonometric

measurement data obtained by receiving synchronized signals

broadcast from multiple orbiters and

(2) Augmentation systems in three types.

The United States' GPS and Russian GLONASS are the two core

satellite constellations that are currently operating. Maintenance and

technical development, such as provision of new civil frequency and

deployment of lighter/new generation satellites are under way.

Three types of

Augmentation systems:

(a) Aircraft-Based Augmentation System (ABAS)

(b) Satellite-Based Augmentation System (SBAS)

(c) Ground-Based Augmentation System (GBAS)

RAIM is a typical example of ABAS. As SBAS's, the United

States' WAAS is operating, and the European EGNOS, the

Japanese MSAS, and the Indian GAGAN are being

implemented. GBAS is being tested in two states: the US LAAS

and the Australian GRAS.

Overview of GNSS

22

Airborne Based Augmentation System (ABAS)

•Aircraft-based augmentation system (ABAS) augments and/or integrates the information obtained from GNSS elements with other information available on board the aircraft. One type of ABAS is called receiver autonomous integrity monitoring (RAIM), which can be used if there are five or more satellites with suitable geometry in view. Other aircraft-based augmentations can also be implemented and are usually termed aircraft autonomous integrity monitoring (AAIM). Some other augmentation techniques, which are particularly useful for improving availability of the navigation function, employ inertial and altimetry-aiding, more accurate time sources or some combination of sensor inputs. .

•Functions

–Integrity monitoring

•Fault detection and exclusion

•Receiver Autonomous Integrity Monitoring (RAIM)

–Uses GNSS information exclusively

•Aircraft Autonomous Integrity Monitoring (AAIM)

–Uses information such as INS and barometric altimeters

–Availability aiding for the position solution

–Accuracy aiding through estimation of remaining errors in determined ranges

ICAO validated the GNSS SARPs, including ABAS, in June 2000,

which then became official with an Applicability Date of 1 November

2001.

Aeronautical Information Circular (AIC) H20/98, dated 16 July 1998,

provides details of the Australian GPS Receiver Autonomous

Integrity Monitoring (RAIM) Prediction Service. This service is an

enhancement to the pre-flight briefing services provided for those

aerodromes with a GPS non-precision approach. New Zealand,

Tonga, Canada and East Timor now also use the Australian RAIM

Prediction Service.

http://www.gmat.unsw.edu.au/

snap/publications/

hewitson_2003a.pdf

Navigation

Overview International Activities

23

Satellite Based Augmentation System (SBAS)

•SBAS is the ICAO term for what is also commonly known as the Wide Area Augmentation System or WAAS. With this system the correction information is collected from a network of GPS reference stations which are located throughout the country. Since their positions are exactly known, the reference stations correct any measurement errors from the satellites for their area. Correction information from each reference station is gathered and linked to a master station where it is analysed together with local tropospheric as well as ionospheric information. This is then sent via a geo-stationary satellite communications link, currently provided by Inmarsat satellites, to an SBAS receiver on board the aircraft. This correction information is then used to amend the position derived from the signals received directly from the GNSS constellation resulting in increased positional accuracy of the aircraft up to better than 10 meters or up to Cat I precision

•Functions

–Ranging

•Provide an additional pseudo-range signal from a SBAS satellite

–Satellite status

•Determine and transmit the GNSS satellite health status

–Basic differential correction

•Provide GNSS satellite ephemeris and clock corrections (fast and long-term)

–Precise differential correction

•Determine the ionospheric error and transmit ionospheric corrections

WAAS was commissioned in July 2003 for use in all phases of air

navigation in the US including instrument approach with both lateral

and vertical guidance (lateral navigation (LNAV)/vertical navigation

(VNAV)).

EGNOS’s technical validation is to be completed in 2004, to enable

operational use of the EGNOS signal for safety-of-life applications in

2005. Possible evolution scenarios of EGNOS after 2004 were

being assessed.

MSAS is launched and expected to be operational in 2006.

GAGAN project is also being planned to cater to the satellite

navigation augmentation requirements for aircraft operators and

ATS providers in the Indian and neighboring airspace.

User

Core

satellites SBAS satellite

STEP1

Receive GNSS/SBAS signal

STEP2

Create SBAS message

STEP3

Create SBAS signal

STEP4

Uplink to

SBAS

satellite

STEP5

Downlink to

Users

STEP6

Using SBAS

message

Core

satellites

Navigation

Overview International Activities

24

GPS

GBAS

receiver

Monitoring

station

Reference

station

Master

station

Correction

data

Airport Pseudolite

Positioning

information

Positioning informationGPS

GBAS

receiver

Monitoring

station

Reference

station

Master

station

Correction

data

Airport Pseudolite

Positioning

information

Positioning information

Ground Based Augmentation System (GBAS)

•GBAS is the ICAO term for what is also commonly known as Local Area Augmentation System or LAAS. This provides increased position accuracy by sending GNSS differential corrections to aircraft to enhance the aircraft's position accuracy.

This is achieved by having a GPS reference at an accurately surveyed position. The GPS position determination is compared against the known reference position and the difference taken into consideration. In practice for GBAS , several such GPS reference receivers may be utilised to provide the difference information with the corrections compared so that they do not fall outside a preset tolerance. The additional reference receivers are to ensure integrity is maintained.

The correction information is sent to aircraft via a VHF datalink where the GBAS receiver takes into account the correction to improve its own position location. Position accuracies of 1 meter or better can be achieved to attain precision approach landing capability from CAT I to CAT III.

•Functions

–Provide locally relevant pseudo-range corrections

–Provide GBAS-related data

–Provide final approach segment data

–Provide predicted ranging source availability data

–Provides integrity monitoring for GNSS ranging sources

LAAS ground facilities, from its first deployment, will support both CAT

I instrument approaches and the GBAS positioning service at selected

airports. The US’s FAA awarded a contract in April 2003 for the design,

development and production of the LAAS ground facility. After

validating the system design, the FAA plans to install a limited number

of ground systems throughout the US. LAAS

GRAS, for which the validation of draft SARPs is being progressed

with the aim of presenting the completed validation to the Navigation

Systems Panel of ICAO in May 2004. Australia had built a GRAS test

bed to facilitate the validation of the GRAS SARPs.

Navigation

Overview International Activities

25

RAIM

Receiver Autonomous Integrity Monitoring(RAIM) is an algorithm

which gives an indication if the GPS can be used for an intended

flight.

The RAIM availability (or ability of a GPS receiver to provide a

RAIM warning) is dependent on the number of satellites available

or in view by the GPS receiver. If there are less than certain

number at any point in time at some location then this is

identified as a 'RAIM hole' (or RAIM unavailability). In this

condition, the accuracy of the position indicated by the GPS

receiver can not be guaranteed, and requirement defined by

ICAO can not be met.

It is basically a function of the geometry of the GPS satellites

overhead of the receiver. Additionally, some satellites may have

been taken out for 'maintenance' by the owners of the GPS

constellation—the U.S. Department of Defence (DoD). GPS

NOTAMS or Notice Advisories to Navstar Users (NANUs as they

are called) are disseminated by the DoD prior to any planned

GPS satellite outage. (See US Coast Guard Website)

RAIM prediction tools are provided by some authorities as like auger

by Eurocontrol (http://augur.ecacnav.com/), RAIM prediction service by

Airserviceaustralia (http://www.airservicesaustralia.com), etc..

RAIM outage data is distributed by AFTN or specific route on request

base.

Navigation

Overview International Activities

26

RNP RNAV

RNP (Required Navigation Performance) is a statement of navigation

performance accuracy necessary for operation within a defined airspace.

RNP can include both performance and functional requirements, and is

indicated by the RNP type.

RNP type is used to specify navigation requirements for the airspace.

ICAO has standardized the following RNP Types, RNP-1, RNP-2, RNP-

12.6 and RNP-20.

RNP

RNAV

RNP RNAV

Desired Path

True Position 4NM

95% probability

4NM 4NM

RNAV (Area Navigation) is a way of calculating your own position, using the flight safety satellite equipment and installed navigation

devices to navigate the desired course. The airways until now have made mutual use of the flight safety satellite equipment, which has often

led to broken line routes.

It is important to distinguish between RNP and RNP RNAV

operation. In ―RNP-x RNAV‖ airspace, performance requirements

include containment. Containment is a set of interrelated parameters

used to define the performance of an RNP RNAV navigation system.

These parameters are containment integrity, containment continuity,

and containment region. The accuracy requirement is the 95% of TSE.

Integrity and continuity are specified relative to a containment region,

whose limit is equal to twice the RNP value.

Multip

le tra

ck

RNP value x 2 =

Containment Limit RNP value

Desired Path

The containment region quantifies the navigation performance where the

probability of an unanunciated deviation greater than 2 x RNP is less than 1x10-5.

Navigation

In the case of the RNAV routes, however, it has been

possible to connect with an almost straight line to any

desired point within the area covered by the satellite

equipment. Setting the RNAV routes has made it possible to

ease congestion on main routes and make double tracks.

27

RNAV Approach

RNAV approach is the method to use RNAV concept for approach.

RNAV approach may have the following merit.

・Create new shortcut approach route

→ Save Fuel

→ Reduce Offset ( Straight in )

・Improve MDA (Minimum Descent Altitude )

→ Improve on-time arrival rate

→ Improve service available rate

RNAV approach can be proceeded on the following condition.

・The airplane is equipped with certain category’s GPS receiver.

・RNAV approach procedure at relevant airport is authorized

・RAIM outage condition is not existed or predicted.

RNAV approach

RUNWAY

VOR/DME approach

RUNWAY

RNAV approach have been implemented at some airports.

Navigation

Overview

International Activities

28

Navigation WGS-84

The WGS-84 was developed to provide for more precision and

continuing updating of geodetic gravitational data also to offer

means for interrelating positions based on various geodetic

systems or datum through a system of coordinates that consider a

single earth center as its fixed system. The WGS-84 represents

the model of geocentric, geodetic and gravitational earth that uses

data and technology available as of 1984. Such system allows the

user to relate geographic data, such as coordinates obtained from

a source based on a local datum, with another source. The WGS-

84 is an ideal system for global navigation applications such as

international air operations. In a static survey modality, the

precision of geodetic latitude and longitude and geodic height of

WGS-84 is within ± one meter.

In March 1989 the Council of the International Civil Aviation

Organisation (ICAO) accepted a recommendation from its Special

Committee on Future Air Navigation Systems (FANS/4) which

stated:

"Recommendation 3.2/1 - Adoption of WGS 84

That ICAO adopts, as a standard, the geodetic reference WGS 84

and develops appropriate ICAO material, particularly in respect to

Annexes 4 and 15, in order to ensure a rapid and comprehensive

implementation of the WGS 84 system.―

In February 1994 the ICAO Council adopted Amendment 35 to

Annex 11 (Air Traffic Services) and Amendment 28 to Annex 15

(Aeronautical Information Services) to the Convention on

International Civil Aviation which mandated the use of WGS 84 as

the common geodetic reference system for civil aviation with an

applicability from 1 January 1998.

The applicability date for the implementation of WGS 84 was in line

with the ECAC Ministers・decision in relation to RNAV

implementation in 1998, for which WGS 84 implementation was a

pre-requisite.

In March 1997 the ICAO Council adopted Amendment 29 to Annex

15 (Aeronautical Information Services) to the convention on

International Civil Aviation, which mandated the use of the vertical

component of WGS 84 with selective applicability from 5 November

1998.

Overview International Activities

29

Surveillance Surveillance Systems

Overview of Surveillance Systems

SSR Mode S

ADS System

Multilateration System

30

Overview of Surveillance Systems

Oceanic SSR

Mode S

ADS-B

ADS-C

En-Route

TMA

SSR Mode S

Airport Surface

Data fusion of ADS-B,

ASDE, Multilateration,

etc.

ATS Provider

ATS Provider

Multilateration

ADS-B

Communication Satellite

(e.g. MTSAT)

GPS/GLONASS/

GALILEO

ADS-B

ADS-B

ADS-B

Oceanic En-route TMA Major

Airport

ADS-B（State Vector and Intent data）

ADS-C SSR

Mode S SSR

Mode S ASDE /

Multilateration

PSR （Major TMA） Surveillance systems for each airspace

Surveillance Systems Architecture

Surveillance

Overview

31

Overview of Surveillance Systems

Improved radar (SSR Mode S)

Automatic Dependent Surveillance

-Contract (ADS-C)

New Surveillance Systems to resolve the problems Problems in Current Surveillance

Multilateration

System

Blind area exists because of mountains, etc. Constraints to route configuration

Small capacity Low accuracy Only processing ground based data is insufficient to realize future ATM.

Small capacity High workload

Expensive radar system Implementation/maintenance cost (many ground stations are needed)

High implementation/ maintenance cost

Automatic Dependent Surveillance

-Broadcast (ADS-B)

Current Radar Coverage

Procedural ATC for non-radar airspace

non-radar

separation

Current Radar Performance

Surveillance

32

SSR Mode S

Europe

• One country has already implemented SSR Mode S

• Euroconrol and several states in ECAC plans to implement SSR

mode S with data link capability (DAPs) in high density traffic area.

•Elementary Surveillance (From 2003-2005)

•Enhanced Surveillance (From 2005-2007)

• SSR mode S have already deployed in the United States.

• Some data link capabilities are implemented and planned.

•Traffic Information Service for GA (Uplink Service)

•Aircraft Derived Data Extraction (ADDE) (similar to DAPs in

Europe) is planned.

United States

Mikuni-

Yama

Kaseda

0km

200k

m

400k

m

Single Coverage

Double Coverage

≧Triple Coverage

Hachinohe

Johon-zan

Iwaki

Yamada

Japan’s SSR Mode S Coverage in 2005

Surveillance

Question

Answer

Question

Question

Question

Answer

Answer

Answer

Question

Answer

Question

Question

Question

Answer

Answer

Answer

Secondary surveillance radar (SSR), an essential part of air

traffic control, provides aircraft identification and altitude

information. Recent years, however, have brought increased air

traffic congestion, which has magnified the limitations inherent in

the present SSR system. To resolve this problem, an improved

SSR, that is, SSR Mode S, is being standardized by ICAO

(International Civil Aviation Organization). The followings are the

benifits of SSR Mode-S.

• To ensure the interoperability between the current surveillance

system (i.e. SSR) and the next generation surveillance system

(i.e. SSR mode S) during the transition period

• To improve the overall ATM System performance using SSR

mode S data link

• To reduce interference due to traffic growth (e.g. Garbling,

Ghost, Coast, and FLUIT)

• To solve the problem

of mode A code shortage

• To avoid saturating of

transponder reply

• To improve accuracy

of surveillance

Overview

International Activities

33

SSR Mode S (DAPs)

EUROCONTROL and several states in ECAC plans to

implement SSR mode S with data link capability in high density

traffic area. They are evaluating mode S test bed sensors, which

are installed in UK, France, and Germany, respectively. After

that, France is going to introduce 10 SSR mode S stations, and

Germany is going to introduce 12 stations.

To increase accuracy and integrity of surveillance data in high

density traffic area, they plan to downlink aircraft parameters

using GICB. This is what they call ―DAPs‖.

A mode S transponder has 255 registers in it. Airborne FMS

writes specified data into these registers.

Ground mode S sensor reads the data stored in specified

register to derive aircraft parameters, such as aircraft ID, speed,

etc.

Downlink Parameters

24 bits aircraft address

SSR mode 3/A

Aircraft ID (Callsign used in flight)

Transponder capability report

Altitude reporting in 25-foot increments

Flight Status (airborne/ground)

Main objective of the Elementary Surveillance is to solve the

problem of mode A code shortage

Network ATM

System

DAPs (Downlink Aircraft Parameters)

1st Step:

Mode S Elementary Surveillance

2nd Step:

Mode S Enhanced Surveillance

- Aircraft State & Selected Altitude

Future Step

Other intent information

- Weather data, etc.

SSR Mode S

Ground information based on

• FPL

• Radar

• MET

+ Aircraft

Parameters

Overview of European DAPs

Elementary Surveillance

Enhanced Surveillance

Downlink Parameters

Aircraft state Magnetic heading

Speed (IAS/Mach/TAS)

Roll angle

Rate of turn (track angle rate)

Benefit of Enhanced Surveillance

Improve tracking performance in ATM ground systems

Implement controller monitoring tools (e.g. Conformance Monitoring)

Enhance Safety Net Systems (e.g. STCA, MTCD, MSAW)

Pave the way for future applications (e.g. position, next waypoints)

Vertical rate

True track angle

Ground Speed

Short term intent

Selected altitude

Surveillance

34

SSR Mode S (TIS)

The Traffic Information Service (TIS) is a Mode S Data Link

service that delivers automatic traffic advisories to pilots.

The goal of TIS is to provide an affordable means to assist

the general aviation (GA) pilot in visual acquisition of

surrounding air traffic. The service is automated and

functions without increasing the workload of air traffic

controllers. The system does not require any changes in the

equipage of intruder aircraft.

139 SSR mode S stations have already deployed all over

the United States (En Route: 15 sites, Airport: 124 sites)

TIS Applications are installed into 92 airport SSR mode S

sites. TIS operational evaluations are now being carried out

at these airports.

Airborne surveillance range

Horizontal: 7NM radius

Vertical: +3,500ft, -3,000ft

TIS in the United States

Target

Relative Altitude

Altitude Rate

(Climbing or Descending)

Traffic Alert

Architecture

An Example of TIS Display

Surveillance

SSR

Mode S

TIS

Processor

Data Link Control and Display Unit

Mode S Transponder

3500ft

3000ftRadius 7NM

Uplinked Traffic

Traffic which is not uplinked

Service Volume

Overview of TIS

35

ADS System

ADS is an ATS application that provides surveillance information

automatically via data link from aircraft to ground based ATS systems

or other aircraft.

ADS provides the following three major benefits

•Increasing Safety

•Increasing Capacity

•Increasing Efficiency

ADS-C

ADS-C equipped aircraft automatically provide, via a point to point

data link, data derived from on-board navigation and position-fixing

systems, including identification, four-dimensional position, and

additional data as appropriate. The data are transmitted to one or

more ground systems with which the aircraft has previously

established a contract.

ADS-B

ADS-B equipped aircraft periodically broadcast their position,

track, speed, etc. via a broadcast mode data link for use by any air

and/or ground users requiring it. The data are provided by the

onboard navigation system. Any user, either airborne or ground-

based, within range of this broadcast may choose to receive and

process this information. The station originating the broadcast needs

to have no knowledge of what system is receiving its broadcast. As

the result, ADS-B equipped stations can transmit their position more

frequently than ADS-C equipped aircraft. ADS-B is expected to be an

enabler of the next generation ATM.

GPS

ATS Provider

GPS

ATS Provider

Communication

Satellite (e.g. MTSAT)

ADS-C

ADS-B

•Point to point

•Air-to-Ground only

•Contracts are required from

ground

•Acknowledgements are required

•Compatible with ATN, existing

communication infrastructures

(INMARSAT, MTSAT, SITA,

ARINC, ...)

•Broadcast

•Air-to-air & Air-to-ground

•Acknowledgements are not

required

•Frequent position report

•Incompatible with ATN and

ACARS systems

Note: There are three candidate ADS-B link technologies, which are ―Mode S

extended squitter (also called 1090MHz extended squitter)‖, ―VDL Mode 4‖ and

―UAT (Universal Access Transceiver)‖

Surveillance

Overview of ADS Difference between ADS-C and ADS-B

36

ADS System

Available Information Using ADS-C

ADS-C message includes Basic ADS information data and

Optional ADS information data. (shown below)

Basic ADS Information

3-D Aircraft Position

Time

Figure of Merit (FOM)

Optional ADS Information

Aircraft ID

Ground Vector

Air Vector

Projected Profile

Meteorological Information

Short Term Intent

Intermediate intent

Extended Projected Profile

Datalink Datalink Aircraft Aircraft

ADS-C data processing capability is implemented into ODP located in

Tokyo ACC.

The symbol in green is the ADS-capable

aircraft. The symbol in yellow is non-

ADS aircraft, which means HF voice

aircraft.

Based on the ADS report, ODP-3

extrapolates the aircraft position at 1

minute interval and shows it to the

controller continuously.

Japan

Australia

North Atlantic

ADS-C has already implemented for oceanic airspace and continental non-

radar airspace in Australia. ADS-C data is processed by ATC automation

system, and the processed data, air traffic picture, is provided to controller

working positions. ADS-C targets are superimposed with other targets such

as radar targets, flight plan based targets on ATC displays.

RADAR Target ADS-C Target Note: Figure of Merit (FOM) indicates the figure of merit of the

current ADS-C data. The information consists of the Position

accuracy and indications

1) whether or not multiple navigational units are operating, and

2) whether or not ACAS is available. FANS 1/A Automatic Dependent Surveillance WayPoint Report (ADS WPR)

trials are underway in the following NAT oceanic Control Areas (CTAs):.

Gander Oceanic CTA

Shanwick Oceanic CTA Reykjavik Oceanic CTA

Santa Maria Oceanic CTA

Surveillance

International Activities

37

ADS System

Three link solutions are being proposed as the physical layer for relaying the ADS-B position reports: 1090 MHz Mode S Extended

Squitter (ES), Universal Access Transceiver (UAT) and VHF Data Link (VDL) Mode 4. The FAA has announced its selection of the 1090

MHz ES and UAT as the mediums for the ADS-B system in the United States. 1090 MHz ES will be the primary medium for air carrier

and high-performance commercial aircraft while UAT will be the primary medium for general aviation aircraft. Europe has also chosen

1090 MHz as the primary physical layer for ADS-B. However, the second medium has not yet been selected between UAT and VDL

Mode 4.

The existing Mode S transponder (or a stand alone 1090 MHz transmitter) supports a message type known as the ES message. It is a

periodic message that provides position, velocity, heading, time, and, in the future, intent. The basic ES does not offer intent since

current flight management systems do not provide such data – called trajectory change points. To enable an aircraft to send an extended

squitter message, the transponder is modified and aircraft position and other status information is routed to the transponder. ATC ground

stations and TCAS-equipped aircraft already have the necessary 1090 MHz receivers to receive these signals, and would only require

enhancements to accept and process the additional information. 1090 ES will not support FIS-B, due to regulatory requirements.

The UAT system is specifically designed for ADS-B operation. A 1 MHz channel in the 900 MHz frequency range is dedicated for

transmission of airborne ADS-B reports and for broadcast of ground-based aeronautical information. UAT users would have access to

the additional ground-based aeronautical data and would receive reports from proximate traffic (FIS-B and TIS-B).

The VDL Mode 4 system could utilize one or more the existing aeronautical VHF frequencies as the frequency physical layer for ADS-B

transmissions. Mode 4 uses a protocol (STDMA) that allows it to self-organizing, meaning no master ground station required. This

medium is best used for short message transmissions from a large number of users. VDL systems are capable of increased range in

comparison to L Band Mode S (1090 MHz) or UAT systems.

Surveillance

UAT

VDL-MODE 4

MODE-S ES

Solution for ADS-B

38

ADS System

Available Information Using ADS-B

ADS-B message includes the minimum set of information and the additional

message elements. (shown below)

Minimum set of information

Emitter category

Emitter identifier

3-D Aircraft Position

Aircraft ID

FOM

ADS-B Applications

Air-to-Ground Enhanced Surveillance

ADS-B improves air-to-ground surveillance in both radar areas and non-

radar areas, where many kind of parameters are used.

ACAS(Airborne Collision Avoidance System)

ACAS will be enhanced using ADS-B because of its high azimuth accuracy.

ASAS(Airborne Separation Assistance System)

ASAS is one of the ADS-B applications and it will be realized using ADS-B.

A-SMGCS (Advanced Surface Movement Ground Control Systems)

Aircraft broadcast their own position using ADS-B, and this data acquisition

system receive it. Then those position data are transferred to the A-SMGCS,

and A-SMGCS calculate most appropriate guidance course for aircraft.

Additional message elements

Ground vector

Air vector

Short term intent

Rate of turn

Aircraft Type

ATS Provider

ASAS

enhanced surveillance

enhanced surveillance

ACAS

Runway

ASAS ASAS

ASAS Example of using ASAS in final approach

TIS-B / FIS-B

A-SMGCS

Surveillance

Traffic Information Services-Broadcast (TIS-B)

A ground-based uplink report of proximate traffic that is under surveillance by ATC but is not

ADS-B-equipped. This service would be available even with limited ADS-B implementation.

Flight Information Services-Broadcast (FIS-B)

A ground-based uplink of flight information services and weather data.

39

ADS System

Using VDL mode 4 equipment, demonstration and experimental flights

were executed in Russia. They plans to implement VDL mode 4 ground

infrastructures in 2002 - 2004

Russia

Australia

APANPIRG/14

Australia has just started the operational

trial in 2003 (Burnett Basin Trial). They

plan to implement ―ADS-B out‖ to

enhance ATC Surveillance for non-

radar area. they plan to apply 5NM

radar like separation standards.

Link Decision in July, 2002

Mode S extended squitter for aircraft that fly in high altitude

airspace

UAT (Universal Access Transceiver) for GA

Interoperability between 2 links will be provided by multi-link

gateway service via TIS-B

Safe Flight 21 Project: Feasibility assessment of technologies for Free Flight

Evaluations in Ohio River Valley

Evaluated 3 links (VDL-4, 1090MHz ES, UAT)

Evaluate effectiveness of ADS-B Application

Evaluations in Capstone Program (Alaska)

Evaluated 3 links (VDL-4, 1090MHz ES, UAT)

Started to operate Radar-like services using ADS-B

target in a part of non-radar airspace of Alaska region

from January 1, 2001.

United States

ADS-B Projects in Europe NUP II (NEAN Update Programme II )

MEDUP (ADS Mediterranean Update Programme )

MFF (Mediterranean Free Flight Programme )

MA-AFAS (More Autonomous - Aircraft in the Future ATM System)

SEAP (South European ADS pre-implementation Programme )

First Step: Package 1 (Developed by CARE/ASAS)

Ground Surveillance Applications

ATC surveillance for en-route airspace, TMA, non-radar

area, airport surface surveillance

Aircraft derived data for ATC tools.

Airborne Surveillance Applications

Enhanced traffic situational awareness

Enhanced visual acquisition for see & avoid, etc.....

Europe

Red: radar coverage

Blue: ADS-B coverage (Plan)

Mongolia

Japan

Conclusions 14/20 - Near term ADS-B Data link selection

Mode S Extended Squitter (1090 ES) be used as the data link for ADS-B

radar like services in the ASIA/PAC Region in the near term.

Conclusions 14/21 - Target date of ADS-B Implementation

States, where necessary to do so, be encouraged to implement

―ADS-B out‖ for ground-based surveillance services in ASIA/PAC Region

on a sub-region by sub-region basis with a target date of January 2006.

Mongolia plans to implement ADS-B for both domestic and international

airspace, using VDL mode 4 for domestic flights, and mode S extended

squitter for international flights.

ADS-B implementation Plannning WG

has been organized in 2000, in which

operational case studies (OCSs) and etc.

are executed.

Dep

C-Runway

A-Runway

Runway crossing

OCS for HND

Surveillance

International Activities toward Implementing ADS-B

40

Multilateration System

Multilateration relies on signals from an aircraft’s

transponder being detected at a number of receiving stations

to locate the aircraft. It uses a technique known as Time

Difference of Arrival (TDOA) to establish surfaces which

represent constant differences in distance between the target

and pairs of receiving stations, and determines the position of

the aircraft by the intersection of these surfaces.

The accuracy of a multilateration system is dependent on

the geometry of the target in relation to the receiving stations,

and the accuracy to which the relative time of receipt of the

signal at each station can be determined.

Multilateration is mainly used for airport surface and

terminal area surveillance, although with careful design and

deployment it may be used in enroute surveillance

applications.

The advantages of multilateration

• It uses established SSR transponder technology.

• It is suitable for surface surveillance. This however relies on

aircraft being equipped with Mode S transponders since Mode

A/C transponders are normally prevented from replying to

interrogations while the aircraft is on the ground.

The disadvantages of multilateration

• It relies on a transponder signal being correctly detected at

four or more receiving stations. This poses problems finding

suitable sites for receivers, especially in enroute surveillance

applications.

Principle of Multilateration System

Europe

Multilateration units have already implemented to London-Heathrow,

Frankfurt, and other large airports in Europe.

United States

MultilaterationProcessing

Station

AB 123Alt 010

ATC Display System

1

Transponder Reply or Mode S squitter

Transponder Reply may bereply to interrogation from

multil ateration system, or

reply to SSR interrogation

(Mode A, C, or S)

Ground

communications

network

4

3

2

MultilaterationStation

Calculated surfaces of

constant time difference

Aircraft

ReportsSurveillance

Data Processor

Japan

The United States are .evaluating the multilateration system as a

sensor for the airport surface and terminal surveillance within OpEval

3 of Safe Flight 21 program. It has already become operational in

several airports.

ENRI (Electronic Navigation Research Institute) is executing

technical evaluations of multilateration system at Sendai Airport.

Surveillance

Overview International Activities