How It Works?

Development

ATC RADAR Types

Benefits and Disadvantages

An Accident

RAdio Detection And Ranging

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

Huelsmeyer’s Telemobiloscope

“Freya” was the first RADAR produced for the German Navy (1937)

Land-based aircraft detection RADAR Max range of 100 nm Over 1000 built throughout the war Installed along Germany’s northern coast

CHAIN HOME was a network of RADARs positioned along the coast of England (1939)

Primary Surveillance RADAR Secondary Surveillance RADAR

En Route RADAR

Airport Surveillance RADAR

ASDE

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.

Band Frequency Wave Length Description

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

S 2–4 GHz 7.5–15 cmterminal 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 for airport RADAR. Named X band because the frequency was a secret during WW2.

Airport Surveillance RADAR (ASR) is an approach control RADAR used to detect and display an aircraft's position in the terminal area. These RADARsets 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

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 use an extremely short pulse-width to provide an acceptable range-resolution.

Airport Surface Detection Equipment

Surface Movement RADAR

Ground RADAR

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

Date 12 November 1996

Type Mid-air collision

SiteCharkhi Dadri, Haryana, India

Total fatalities

349

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

How It Works?

Development

ATC RADAR Types

Benefits and Disadvantages

An Accident

Question?