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. Target Range ( Distance ) .2. Target Angels ( Horizontal &

Vertical ) .3. Target Size .4. 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 line, at a constant speed : C = 3*10Speed=

𝐃𝐢𝐬𝐭𝐚𝐧𝐜𝐞𝐓𝐢𝐦𝐞

8

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. Target Range ( Distance ) .2. Target Angels ( Horizontal &

Vertical ) .3. Target Size .4. 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. Target Range ( Distance ) .2. Target Angels ( Horizontal &

Vertical ) .3. Target Size .4. 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

Duplexer

Transmitter

Receiver

Processing

Display

Antenna

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