Air Craft Surveillance
byBikas Chandra Sadashiv
ECE – IGNIT
3rd Year
Air Craft SurveillanceThrough RADAR
• Introduction• RADAR Frequencies• RADAR Applications• Types of RADAR
Topics To Be Covered
Introduction
• RADAR is stand for Radio Detection And Ranging and was developed prior to World War II.
• Today RADAR is extremely important in civil aviation.
• It is used by ATC to monitor and control numbers of aircrafts in airspace as well as by pilot for weather warning and navigation.
Radar Frequencies
• Radar operates on UHF and SHF - Super High Frequency (1 GHz - 30 GHz).
• RADAR systems are in SHF bands because:a) These frequencies are free from disturbance.b) Higher frequency, shorter wavelength,
RADAR more effective.(shorter wavelengths are reflected more efficiently.)
RADAR Applications
RADAR has a wide range applications including1. Ground RADAR : extensively used by Air
Traffic Control to separate aircrafts.2. Airborne Weather RADAR: used by pilots. It
provide pilots with information regarding weather ahead.
Types of RADAR
(RSR) En-Route
Surveillance
RadarTAR-
Terminal Approach
Radar (PSR &
SSR)
SMR (Surface
Movement Radar)
Classifications of RADAR
1) En-Route Surveillance Radar (RSR)
• En-Route Surveillance Radars (RSR) are long range radars which the signal goes to 300 NM.
• It operates with frequency between 1 to 2 GHZ.
• It used for airway surveillance to provide range and bearing of aircraft.
**Surveillance: close observation, especially of a suspected spy or criminal.
2) Terminal Approach Radar (TAR)• TAR is a high definition radio detection
device which provides information on identification, air speed, direction and altitude of aircraft to assist air traffic controllers to track the position of aircraft in the air within the vicinity of the airport.
• This radar gives the air traffic controller a better or true picture of all aircraft flying in his control zone.
2) Terminal Approach Radar (TAR)
PSR
SSR
Working of PSR : • Primary Surveillance Radar (PSR) transmits a high
power signal. • When a signal strikes an object or target, some
signal energy is reflected back and is received by the radar receiver.
• RADAR receiver will plot the direction and the distance of the target (aircraft) from the radar station.
• Thus, the ATC could know the position of aircraft. through the RADAR display.
Primary Surveillance Radar (PSR)
Primary Surveillance Radar (PSR)
Antenna
TransmittedPulse
TargetCross
Section
Propagation
ReflectedPulse
(“echo”)
Radar observable:• Target range• Target angles (azimuth & elevation)• Target size (radar cross section)• Target speed (Doppler)
Secondary Surveillance Radar (SSR)
Working of SSR :• Secondary Surveillance Radar (SSR)
transmits an interrogation signal which is received by the target aircraft.
• The aircraft transponder sends back a coded reply to the ground radar equipment.
• From the coded signal, information of the aircraft’s call sign, altitude, speed and destination.
• SSR requires an aircraft to be fitted with transmitter/receiver called as transponder.
How SSR Works?
• The ground secondary radar transmits 1030MHz signal.• The aircraft radar receives on 1030MHz and transmits back
0n 1090MHz.• The transponder reply is more powerful than the reflected
radar signal allowing for far greater range. (250nm).
3) Surface Movement Radar (SMR)
• SMR installed at airport (at top of ATC tower building) to provide a very accurate radar display in all weathers and conditions of visibility. (operate with frequency 18-40Ghz)
• SMR radar display can show all of airfield infrastructure including aircraft movements on runway, taxiway and apron.
• It is designed to provide clear display of all aircraft on runway or taxiway so that ATC can ensure runway are clear for take-off/landing and also guide aircraft to apron in order.
3) Surface Movement Radar (SMR)
RADARS USED IN ATC
• Airport Surveillance Radar (ASR)• Air Route Surveillance Radar (ARSR)• Airport Surface movement Detection
Equipment (ASDE)/Advanced Surface Movement Guidance & Control System (ASMGCS)
• Precision Approach Radar (PAR)• Mono-pulse Secondary Surveillance Radar
(MSSR)
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