adsb_futureairport_2010

8/6/2019 adsb_futureairport_2010

1/4

DELHI

MOSCOWMUMBAI

KOLKATA

HYDERABAD

KIEV

ALMATY

SHANGHAI

TASHKENT

NEW YORK

LOS ANGELES

LONDON

AMSTERDAM

PARIS

FRANKFURT

ZURICH

ISTANBUL

TEHERAN

DUBAI

RIYADHBAHRAIN

KUWAIT

ABU DHABI

MAURITIUS

BRUSSELS

HELSINKI

TOKYO

OSAKA

SEOUL

SINGAPORE

HONG KONG

TAIPEI

GUANGZHOU

BEIJING

KUALA LUMPUR

KATHMANDU

COLOMBO

BANGKOKCHENNAI

India opens upHow Delhi airport is expanding Indias horizons

futureairportAir Traffic Control | Future Routes | Ground Operations | IT & CommunicationsBaggage & Cargo Handling | Commercial Strategy | Passenger Handling

www.futureairport.com

www.airport-technology.com

Special Show Edition

I n v e s t i n g i n t h e f u t u r e o f a i r p o r t s ISSUE 1 2010 5.95 8.00 $8.95


2/4

Company insight > Future ATC

Future Airport| www.futureairport.com66

German ATC supplier COMSOFT has

developed its surveillance products to

provide an end-to-end solution. Having

established itself as a competent and reliable supplier

of equipment for processing, tracking, analysing and

displaying airspace information it has turned its

attention to the collection of surveillance information.

The result is Quadrant.

Quadrant was developed from a single automatic

dependent surveillance-broadcast (ADS-B) sensor

into a comprehensive and flexible surveillance

solution. It now incorporates multiple ADS-B sensors

with a central processor to enable multilateration;

provides local transmitters for site monitoring,

reference transponders and ground-based vehicle

transponders; and includes a distributed interrogation

capability to extract information from Mode A, Mode

C and Mode S aircraft.

Quadrant was produced to meet the changing requirements of

established and emerging air navigation service providers (ANSPs). The

flexibility of the system makes it attractive for many users whether they

are looking at a token ADS-B capability, a method of enhancing andaugmenting an existing capability or a complete operational

surveillance system. The development path has adapted to meet the

changing needs and emerging markets.

ADS-B

Quadrant emerged from an existing multilateration system and

began with the creation of a robust and flexible ADS-B sensor.

Initially ADS-B was seen as the key market because it provided an

expandable surveillance solution with the addition of more sensors.

The Quadrant ADS-B sensor is specifically designed for deployment

in remote areas where regular access for maintenance is not

convenient. It is also small enough to be carried as hand-baggage

and consumes less than 10W. It can obtain its

power from an existing supply, via solar panels or

over the Ethernet feed that provides its

connectivity. The sensor is intended to be installed

once and does not require any routine on-site

maintenance as there are no moving parts and no

fans (see Figure 1, left).

Standards change, improvements need to be

made and occasional defects have to be fixed, so

all software and firmware on a Quadrant ADS-B

sensor can be installed, updated, monitored and

controlled remotely via the Ethernet connection.

The Quadrant Control and Monitoring System

(QCMS) provides a comprehensive monitoring

capability and enables loading, coverage and

numerous performance statistics to be reported.

The compiled ADS-B information is provided via

ASTERIX CAT021 messages. All recent versions are supported andindividual clients may select the version they wish to receive, while

new versions are easily incorporated through the remote upgrade

process. Up to 20 clients can connect to each sensor to receive an

independent stream each with a specific version and a bespoke

user application profile (UAP). However, most users prefer to use

the often limited bandwidth between remote sites to transfer data

to a single point from where it can be integrated and distributed in

a highly flexible way using the Quadrant Integrator.

Figure 1: Quadrant ADS-B Sensor

Developed to meet the requirements o air navigation service providers, Quadrants fexibility makes itattractive or users looking at a token ADS-B capability, a method o enhancing and augmenting anexisting capability or a complete operational surveillance system, writesCOMSOFTs Michael Leeson.

Quadrant: from Mode S

to multilateration

Quadrant was produced to meetthe changing requirements oestablished and emerging airnavigation service providers.

Figure 2: Principle of multilateration


3/4


Future Airport| www.futureairport.com 67

Multilateration

A geographically distributed network of Quadrant ADS-B sensors

provides the basis of a multilateration system, which is an integral part

of the ADS-B sensor and no modification or upgrade is necessary.Quadrant began as a multilateration system and this is where its

strengths still lie. The ADS-B sensor and Quadrant Central Processor

share the processing necessary to perform multilateration and this

minimises the bandwidth demands, while the detection of a

transmitted signal, its decoding into recognisable formats and the

timing of its arrival are all performed within the sensor. There is no

need to transfer huge amounts of sampled data because the

intelligence to recognise the message resides in the sensor. New RF

messages and improved detection algorithms can all be uploaded to

the sensor remotely too.

Detection and timing of signals is only part of the multilateration

solution; the remaining intelligence lies within the Quadrant Central

Processor. Synchronisation of clocks in each sensor is a major issuewith any multilateration system and the Quadrant approach makes

use of the distributed intelligence of the system. The clock within

each sensor is aligned with those in other sensors by processing

timing events from reference transponders and GPS. The Central

Processor uses the available information to maintain an accurate and

consistent time. This provides Quadrant with positional accuracy to

support ground movement, local and wide area surveillance (see

Figure 2, bottom left).

The parallel development of multilateration and an ADS-B

capability has meant that the obvious method for identifying a target

is via its 24-bit ICAO address (more commonly known as the Mode S

address). The availability of this address in both long and short

squitter messages, as well as many other downlink formats, makes it

easy to associate multiple messages and multilateration plots with

the same aircraft. Quadrant is able to create target tracks, based

upon this address, and collect a rich data set used to produce both

ADS-B and multilateration outputs.

Multilateration surveillance data is provided as ASTERIX CAT020

format messages. In common with the ADS-B output, all recent

versions are available and each client may select the preferred

version. New versions are incorporated by updating the software in

the Central Processor.

Other aircraft transmissions can also be used to generate

multilateration plots including Mode A and Mode C replies.

Quadrant can optionally include other plot association algorithms,

based upon timing and geographical proximity, to enable additional

plots to contribute to a target track. Making use of the content of

these messages is harder to achieve; indeed, it is not possible to

differentiate between Mode A or Mode C without knowledge of the

related interrogation. However, there is much useful information

that can be obtained from interrogation and hence Quadrant

provides a complete interrogation capability.

Interrogation

In keeping with the Quadrant philosophy, the interrogation system is

provided by multiple remote transmitters, which contain some of the

required intelligence, and a Quadrant Interrogation Controller. Multiple

transmitters enable a wide airspace to be covered with low-power

transmissions, which are targeted at a small area. This reduces the

impact of Quadrant on other surveillance systems by reducing theamount of False Replies Uncorrelated In Time (FRUIT).

The Quadrant Interrogation Controller was developed to integrate

completely with the Central Processor in order to meet the demand for

multilateration of aircraft without ADS-B capability. It determines the

information required from each aircraft, identifies the most suitable

transmitter and schedules the necessary uplink formats. The

transmitter network operates to the same time frame as the Central

Processor and this enables interrogations and replies to be correlated.

Transmitters have the ability to vary transmission power and

can use omnidirectional and sectorised antennas to restrict the

transmission to the necessary area. The choice of antenna pattern, the

optimal power and indeed the location of transmitters is crucial to

achieving good performance at an acceptable price. The location of

There is no need to transfer hugeamounts of sampled data becausethe intelligence to recognise themessage resides in the sensor.

Figure 3: Quadrant Interrogator

Figure 4: Coverage tool


4/4


Future Airport| www.futureairport.com68

multilateration sensors is also crucial to the achievable accuracy of the

system. As the sensors and transmitters are designed to be installed

once and left, and as the installation geography is the most costly

component to change, Quadrant uses numerous modelling and

analysis tools to determine a suitable configuration (see Figure 3,previous page).

Monitoring, analysis and expandability

The Quadrant coverage tool provides a model of system performance

based upon terrain data, antenna patterns and the performance of

sensors and transmitters. The ADS-B sensor is able to detect aircraft

beyond 250NM if there is line-of-site. In general, it is terrain which

determines coverage and multilateration accuracy that drives the

selection of sites. Location of transmitters and sensors, and the

expected performance can be visualised (see Figure 4, previous page).

A model is only as good as its data and no chances are taken with

the Quadrant coverage tool. Real sensors can be deployed on a

temporary basis to any potential site and the actual coveragemeasured using available ADS-B reports. Coverage, loading and

distribution of downlink formats are just some of the numerous sensor

statistics available

ADS-B and multilateration are new concepts for many customers

and are considered a risky alternative to radar. The advantages over

radar are attractive: higher accuracy, lower cost, greater redundancy,

but radar is a well-known technology and potential users must be

convinced and assured that Quadrant is a reliable and viable

alternative. A phased introduction is the

recommended approach and is beneficial

in many ways. For example, a single

sensor provides ADS-B coverage but also

enables a huge amount of data to becollected and analysed; additional sensors

increase the coverage area incrementally

but also enable multilateration to be

demonstrated. ADS-B and multilateration

is completely passive and can work

alongside existing secondary surveillance

radars (SSRs) and will make use of the

responses to their interrogations. When

the amount of parasitic interrogations is

insufficient, or when an SSR is replaced,

the active components of Quadrant can

fill in the gaps.

Every Quadrant installation is different

and brings new challenges. The robust

technology, the intelligent design and

the reassuring analysis provided ensure

that each challenge is met fully, safely

and reliably.

COMSOFT GmbH is a leading software

specialist of the ATC domain, delivering

technical expertise and services to civil

and military aviation authorities and

ANSPs. Operating for more than 30 years

in over 60 countries around the world, it

specialises in ATM solutions, aeronauticalmessage handling and information

management, surveillance

communication, recording and, of course,

in ADS-B and multilateration.

Further informationCOMSOFT GmbH

www.comsoft.aero

is making the link

COMSOFTCOMSOFT GmbH Wachhausstr. 5a 76227 Karlsruhe Germany

T +49 721 9497 0 www.comsoft.aero [email protected]

aftn/cidin/amhs systems

aeronautical information systems

surveillance communication

surveillance display & processing

integrated radar/voice recording

atm systems & safety netsasterix tools & systems

artas installations & services

ads-b & multilateration sensors

Visit us:

9 - 11 March 2010

Amsterdam RAI

Stand H216

_ _ _ . . .

adsb_futureairport_2010

Documents

Transcript of adsb_futureairport_2010