RADAR System
Anas Abu Siam
Introduction
• RADAR Is a device or system for detecting and locating a
target by radio waves .
• The term RADAR was coined in 1940 by the United States
Navy as an acronym for RAdio Detection And Ranging .
The Idea
• If you shout in the direction of a sound-reflecting object
( like a rocky canyon or cave ) , you will hear an echo .
• If you know the speed of sound in air , you can then
estimate the distance and general direction of the object .
• Radar uses electromagnetic power pulses in much the
same way .
Functions Of RADAR
1.
2.
3.
4.
Target Range ( Distance ) .
Target Angels ( Horizontal & Vertical ) .
Target Size .
Target Speed .
1. Target Range
• Radar measurement of range, or distance, is made possible
because of the properties of radiated electromagnetic
energy.
• This energy normally travels through space in a straight
8
line, at a constant speed : C = 3*10
Speed =
𝐃𝐢𝐬𝐭𝐚𝐧𝐜𝐞
𝐓𝐢𝐦𝐞
𝑫𝒊𝒔𝒕𝒂𝒏𝒄𝒆 = 𝒄 ∗ 𝒕𝒊𝒎𝒆
1. Target Range
• Duty Cycle = τ / T
• T : time repetition interval
τ : pulse width
1. Target Range
• Final equation to find the range :
Distance = C *TR/2
Functions Of RADAR
1.
2.
3.
4.
Target Range ( Distance ) .
Target Angels ( Horizontal & Vertical ) .
Target Size .
Target Speed .
2. Target Angels
Elevation
Azimuth
2. Target Angels
• There are two methods to estimate the
angels:
I. Mechanical ( Motor ) :
2. Target Angels
II. Array of Antenna :
Functions Of RADAR
1.
2.
3.
4.
Target Range ( Distance ) .
Target Angels ( Horizontal & Vertical ) .
Target Size .
Target Speed .
3. Target Size
I.
Magnitude of return .
II. Radar Cross Section (RCS) : is a virtual area representing
the intensity of the reflection.
4. Target Speed
• Doppler Effect : Frequency shift is caused by motion that
changes the number of wavelengths between the reflector
and the radar. That can degrade or enhance radar
performance depending upon how that affects the detection
process .
RADAR as a System
Antenna
Duplexer
Transmitter
Receiver
Display
Processing
Display
Radar Types
• By the number of antennas :
– MonoStatic : Single Antenna
– BiStatic : Two Antennas
– MultiStatic : More than 2 Antennas
• By Scan Strategy :
– Pulse RADAR
– Continuous Wave RADAR
• By Source of the power :
– Active Radar
– Passive Radar
The End