RADAR

MSA 606  AVIATION AND AEROSPACE COMMUNICATION AND CONTROL SYSTEMS

Presented by Yi-Fan (Tom) Chen

Contents

How It Works?

Development

ATC Radar Types

Benefits and Disadvantages

An Accident Example

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How It Works?

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RAdio Detection And Ranging

Microwave (1GHz to 110Ghz)

Higher frequency get higher resolution, but shorter range.

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Microwave Band

Band

Frequency

Wave Length

Description

L 1–2 GHz 15–30 cm long range air traffic control and surveillance; 'L' for 'long'

S 2–4 GHz 7.5–15 cm

terminal air traffic control, long-range weather, marine radar; 'S' for 'short'

X 8–12  GHz

2.5–3.75 cm

missile guidance, marine radar, weather, medium-resolution mapping and ground surveillance; in the USA the narrow range 10.525 GHz ±25 MHz is used for airport radar. Named X band because the frequency was a secret during WW2.

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Development

The first “practical” application of radio waves for RADAR was invented by Christian Huelsmeyer in 1904, German for ship detection (Range = 3km)

Huelsmeyer’s Telemobiloscope

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Development cont.

“Freya” was the first radar produced in quantity for the German Navy

Land-based aircraft detection radar Operated at 120 to 130 MHz Peak Power output of 15 to 20 kW Max range of 100 nm Over 1000 built throughout the war Installed along Germany’s northern coast

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Development cont.

CHAIN HOME was a network of “floodlight” radars positioned along the coast of England

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Categories

Primary Surveillance Radar Secondary Surveillance Radar

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Transponder

Developed from the military IFF (identification, friend or foe) since WWII

Mode A — provides a 4-digit octal identification code for the aircraft, known as a squawk code, assigned by the air traffic controller

Mode C — provides a 10-bit binary Gray code for the aircraft's pressure altitude

Mode S — each aircraft can be assigned a fixed, unique ICAO 24-bit, including position and velocity

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Radars for ATC

En Route Radar

Air Surveillance Radar

Weather Radar

ASDE

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En Route Radar

En-route radar systems operates in L-Band usually. These radar sets initially detect and determine the position, course, and speed of air targets in a relatively large area up to 250 nm.

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Air Surveillance Radar

Airport Surveillance Radar (ASR) is an approach control radar used to detect and display an aircraft's position in the terminal area. These radar sets operate usually in S-Band, and are capable of reliably detecting and tracking aircraft at altitudes below 25,000 feet (7,620 meters) and within 40 to 60 nautical miles (75 to 110 km) of their airport.

Terminal Radar

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Weather Radar

Microburst Radar (MBR)

Doppler WeatherRadar

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ASDE

The Surface Movement Radar (SMR) scans the airport surface to locate the positions of aircraft and ground vehicles and displays them for air traffic controllers in bad weather. Surface movement radars operate in X- Band and uses an extremely short pulse-width to provide an acceptable range-resolution.

Airport Surface Detection Equipment

Surface Movement Radar

Ground Radar

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Benefits and Disadvantages

Provide a controller a global picture about what is going on in the air

Prevent midair collision and runway incursion by using TCAS and ASDE

Can be affected by the weather and terrain

Has limited range and can not cover all the airspace

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An Accident Example

Date 12 November 1996

Type Mid-air collision

Site Charkhi Dadri, Haryana, India

Total fatalitie

s349

Charkhi Dadri mid-air collision

Saudi Arabian Airlines Flight 763, 747-100

Air Kazakhstan Flight 1907, IL-76

•Flight 1907 did not follow the ATC instruction to maintain 15,000 ft

•Also not equipped TCAS

•ATC only have primary surveillance radar

•The same route for arrival and departure

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The Future

ADS-B

Satellite Based Surveillance

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Review

How It Works?

Development

ATC Radar Types

Benefits and Disadvantages

An Accident Example

The future

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References

http://www.radartutorial.eu/index.en.html

http://math.la.asu.edu/~kuang/LM/030902-Radar_History10.pdf

http://en.wikipedia.org/wiki/Radar

http://en.wikipedia.org/wiki/1996_Charkhi_Dadri_mid-air_collision

The End

Question?