Chương 3: Radar Mode-S pdf

Trường Đại học Bách Khoa Hà Nội Hanoi University of Science and Technology Hệ thông Thông tin Hàng Không Chương 3 Radar Mode-S © HUST 2012... Teminologies - Radar: Radio Detec

Trường Đại học Bách Khoa Hà Nội Hanoi University of Science and Technology

He thong Thong tin Hang Khong

TS Đỗ Trọng Tuan

Bộ môn Kỹ thuật thông tin

© HUST 2012

Trường Đại học Bách Khoa Hà Nội Hanoi University of Science and Technology

Hệ thông Thông tin Hàng Không

Chương 3

Radar Mode-S

© HUST 2012

Teminologies -

Radar: Radio Detection and Ranging

SSR: Secondary Surveillance Radar

Aeronautical Telecommunic

Managemen Data Displa Data Entry Managemen

ATN ROUTER

ee — - ee

VHF Subnetwork Satellite Subnetwork Mode S Subnetwork HF Subnetwork

ATN ROUTER

ATN ROUTER

Service Provider Ground Subnetwork Airline Ground CAA Ground

Aeronautical

Operations

Control

Aeronautical

Operations

Data Base

Weather Data Base

Weather Data Base

FIS ATC Data Base

Primary Radar Si -

Secondary Surveillance Radar _

“* Primary radar relies on passive reflection

“¢ Secondary radar co-located with primary

“* SSR beam interrogates transponders

“* Transponder reply depends on its mode

«* ATC computers use SSR to tag primary echoes

with identifier and height

Š

Radar

1090 MHz

Aircraft NX

Interrogator Return

1030 MHz

Surveillance ¬ Surveillance Radar -,———————== Synchronisation========= > Radar

(SSR) (PSR)

Beacon Video Radar Video

Principle of transponder operation.

«* A transponder is a receiver / transmitter device designed to

transmit a response signal when legitimately interrogated

[NATO definition]

«* An automatic device that transmits a predetermined

message in response to a predefined received signal

[Wikipedia]

ĐẠI HỌC

|

SSR Principle 8 us Identify 3/A —†>406 codes

21 ps Height ? C —0-2047

Amplitude Step=

P1-P3 spacing

eee es >

P{ P2 (Interrogation message) P3

Amplitude Code 7500 - to indicate unlawful interference (hijacking)

Code 7600 - to indicate a communication failure

ñnnnntnn nnnnnnl

Reponse mesasge {

Source: understanding radar systems

«* Mode A (simple system):

= Aircraft identification (Call-sign)

«* Mode C (more advanced):

"= Mode A + altitude

“* Mode S (more recently):

= Mode C + 24 bit address identifier (unambiguous)

= Provides limited air-air and air-ground communications

= Can also provides whereabouts of other aircraft in its vicinity

= Uses digital error-correcting codes for improved reliability

Allocation of 24-Bit Aircraft address to Vietnam:

1000 10 001 xxx XxX XXXXXXXXXX

sidelobe suppression ~

——+

⁄Z_N Azimuth

rotation

Pattern of

main SSR antenna

\

+—— Pattern of omnidirectional antenna

Radar mode S$ 7 -

21 ps Height ? C

Amplitude

A Mode A 8.0 ps

le eae g8 nh Lai

ACG

<x + — +

0.8yus 0.8 us ® usec

(Source: http://web.mit.edu/6.933/www/Fall2000/mode-s/signal.html)

sensor

Data-link processor

'

Interface-to-network communications Mode S transponder

(data-link capable)

Data-link control and display unit

Secondary Radar

Primary Radar Primary Radar

Airport Surveillance Radar (ASR) Air Route Surveillance Radar (ARSR)

IFF Primary Radar

Interrogator - 1.090Ghz ~ 3Ghz for AWACS

~ 10Ghz for

Transponder - 1.030 Ghz Airborne intercept

Co-boresighting of IFF interrogator with radar

AWACS: Airborne Early Warning and Control System

ĐẠI HỌC

Radar mode S

i

Tl a's Pan tard

! oe) f i L „ u HM t ed

a Fam OCR O) Me eee ttle A a en Ole ti mt fro mrims a oh =)

antenna (ASR-970)

Specifications

frequency: 1030 / 1090 megahertzes pulse repetition time (PRT): synchronuous to the primary radar

synchronuous to the primary radar

pulsewidth (P¥¥): depending on mode

receive time:

dead time:

peak power: up to 2 kilowatts

average power: up to 100 watts

displayed range: up to 250 nautical miles range resolution: 500 m

beamwidth: 10 degrees hits perscan:3 6

antenna rotation: synchronuous to the primary radar