Showing posts with label radar. Show all posts
Showing posts with label radar. Show all posts

8 Jul 2020

RADAR Engineering Basics

RADAR Block Diagram- Types of RADAR (Monostatic RADAR and Bistatic RADAR)- Duplexer in RADAR

This video lecture discusses the block diagram of RADAR. Here two Types of Radar are discussed- Bistatic Radar and Monostatic Radar. This Classification of Radar is based on the number of Radar antenna used. In Bistatic radar two separate Antennas are used for transmission and reception purpose while in case of monostatic Radar only one antenna works as a transmitter and receiver antenna. For this purpose the monostatic radar uses duplexer. This video lecture also discusses the functions of Radar duplexer.

RADAR- RADAR System- RADAR Advantages and Disadvantages- Uses of RADAR and Working- RADAR Full Form

In this video you will understand- what is Radar, the basic working principle of Radar, advantages and disadvantages of radar along with uses of Radar (applications of Radar). You will also know the full form of Radar. Radar is an acronym for radio detection and ranging. Radar uses electromagnetic waves (Radio waves) towards the target and analyses the reflected waves (echo signal) to gather some information about it. This video also compares Radar with Sonar (radar vs sonar). Applications of Radar have been categorized mainly in two parts- Civilian applications and military applications.

RADAR Range Equation - RADAR Equation - Derivation of RADAR Range Equation - Range of RADAR

In this video you will get the derivation of Radar range equation. Here you will understand the basics of Radar range equation. You will find here the radar range formula. Radar range equation relates the range of the radar to the transmitter and receiver of the radar, antenna of the radar and target. It is also related to the medium of the environment. This video explains the concept of power density, Gain and directivity of the antenna. The power received by radar and Radar cross section of target has also been covered. You will find here two forms of Radar range equation.

Desirable Qualities of RADAR System - General Requirements for RADAR System - RADAR Engineering

This video is about the qualities of a good Radar system. Following are the general requirements for a radar system. 1.The transmitter of Radar should be able to transmit high power signals so that it can counter the attenuation that is caused in the forward and backward paths. 2.The Radar transmitter should remain silent during the echo period. 3.The receiver of the radar should be very sensitive as it has to catch very weak echo signals. 4.The transmitted signal by the radar transmitter should be highly directive and it should have high gain since it needs to transmit strong signals to counter attenuation.

22 May 2019

RADAR Block Diagram and Working (Bistatic Radar and Monostatic Radar) - Types of RADAR

What is a RADAR?

RADAR stands for "Radio Detection and Ranging" as it uses radio waves (electromagnetic waves) to detect and find the range of an object (target).
The transmitting antenna of the radar transmits radio waves towards the object and analyzes the reflected waves from the target object. After analyzing the reflected waves (echo signal) it can calculate target's distance (range), angle and velocity (if it is moving).
Radars can be classified into two broad categories, based on the number of Antennas used-
Bistatic Radar and Monostatic Radar

Watch the Complete RADAR Video Here

Bistatic RADAR (Block Diagram)

Here you can see the block diagram of Bistatic radar.

Bistatic RADAR Block Diagram

You can observe in this diagram that, the bistatic  radar contains a radar display, a transmitter and a receiver. Transmitting antenna is attached to the transmitter and receiving antenna is attached to the receiver of the radar. 
The job of the transmitting antenna is to transmit radio waves (electromagnetic waves) towards the target that we want to detect. The target object intercepts some part of the transmitted signal and reflects it back towards the receiving antenna. This receiving signal is known as the echo signal. 
Now the Radar receiver analyses these received signals. The radar display shows the information in the raw form, that needs to be analysed by an skilled person. 
The receiver of the radar must be very sensitive to receive weak signals, as the signals get very weak because of the attenuation of the radio waves in the forward and reverse path.
Also the radar transmitter should have high directivity and gain. Directivity of antenna is it's ability to transmit radiations in a particular direction. It should also have high gain since it has to counter losses in the forward and reverse path (before and after reflection from the target).
Now we will understand why it is known as bistatic radar and how it is different from the monostatic radar.
Actually the bistatic radar uses two antennas for transmission and reception purpose separately, that's why it is known as bistatic radar. 

Monostatic RADAR (Block Diagram)

Monostatic radar is the most commonly used form of the radar. Here you can see the block diagram of monostatic Radar-

Monostatic RADAR Block Diagram

As you can see in this block diagram that monostatic radar uses only one antenna for transmission and reception purpose, that's why it is known as monostatic radar (Mono means single and bi means double).
In this block diagram of monostatic radar you can see that it has an indicator, a transmitter and receiver, a duplexer and a single antenna. Observer that here we have not used two separate antennas as the transmitting antenna and receiving antenna. Only one antenna can function as the transmitting and receiving antenna.
Actually the basic working principle of both types of radars (Bistatic and monostatic) is same with some differences.
The radar transmitter transmits electromagnetic waves (radio waves). At the time of transmission the antenna of the monostatic radar works as the transmitting antenna and when these signals are reflected back (echo signal) from the target, the same antenna works as the receiving antenna. This received signal is analysed by the receiver circuitry and the data is shown on the indicator of the radar. 
Now we will understand the role of the duplexer in the monostatic radar-

Functions of the Radar Duplexer

  • The Radar duplexer makes it possible to use single antenna for transmission and reception purpose.

  • The duplexer helps in protecting the sensitive receiver from the high power transmitter.

  • The radar duplexer keeps the transmitter and receiver separate (isolated) at the time of transmission and reception.

Desirable Qualities of RADAR System (General Requirements of RADAR)

A RADAR (Radio Detection and Ranging) system should have the following qualities (General Requirements of RADAR)

  • The transmitted pulse by the radar transmitter should be powerful enough to counter the attenuation (losses) during forward or return Journeys.

  • The radar transmitter should remain silent during the echo period.

  • The receiver should be extremely sensitive and also immune to noise signals since signals are very weak.

  • Directivity of the antenna of the radar should be high. Directivity of antenna is a basic parameter, that is the measure of degree to which the radiation emitted by the antenna is the focused in a particular direction.

  • The gain of antenna should also be high as it is required to transmit strong signals.

21 May 2019

RADAR Basics, Working Principle, Advantages (Benefits), Limitations and Applications (Radio Detection and Ranging)

Basics of RADAR 

  • RADAR Full Form- RADAR is the acronym for Radio Detection and Ranging
  • RADAR was used for the first time in 1942 (during World War II) by US Navy

Principle of working of RADAR

  • Radar sends electromagnetic waves to distant objects and analyses the reflected wave (echo signal) to gather information about that object.
  • Radar is able to detect static or moving targets.
  • With the help of Radar we can easily find the range, angle and velocity of the target.

Advantages of RADAR

  • Radar provides superior penetration capability through any type of weather condition like rain, fog and snow.
  • Radar can be used in day or night.
  • It can detect static or moving targets.
  • Radar can calculate the range and angle of the target accurately.
  • There is no need of any medium for the radar to function, as it uses electromagnetic waves (radio waves) unlike SONAR (Sound Navigation Ranging) that uses water as the medium.
  • As radio waves (electromagnetic waves) are used by the radar, it can be used in space or air.
  • Functioning of Radar is very fast in comparison to Sonar. since Radar uses electromagnetic waves that travel at the speed of light, while the Sonar uses sound waves; and we know that speed of sound is nothing in comparison to speed of light.
  • Radar does not need target Corporation to emit any signals or emission.
  • Radar can be used for quite long Ranges.
  • Radar signals can target several objects at the same time.

Limitations of RADAR

  • Radars cannot identify the color of the target.
  • Radars cannot resolve in the details like human - eye, mainly at short distances.
  • Radar is not able to penetrate the sea (deep sea) to collect data about the target.
  • Radio signals can be interrupted by other signals as they travel through air and space.
  • Radar cannot be used beyond the ionosphere as these signals are deflected back to the earth.
  • Analysis of data that is obtained from the radar needs specialized training.
  • The data obtained from the radar is not complete as the reflected signals cannot report the complete details of the object (target).

Applications of RADAR

Applications of Radar can be broadly classified into two categories-
  • Civilian applications of Radar
  • Military applications of Radar

Civilian applications of Radar

  • Airborne Radar for satellite surveillance
  • Police Radar for directing and detecting speeding vehicles.
  • Radar blind Lander, that helps aircraft to land under bad weather conditions or at night
  • Radar altimeter to calculate height of planes
  • Radar can also be used for help in navigation on ground or sea even under poor visibility or night time it is not affected
  • Radars can be used to find the speed of moving targets like automobiles, guided missiles and shells etc.

Military applications of Radar

  • Radars are used in military to direct guided missiles
  • They are also used for searching submarines and land masses.
  • Radars can be used to detect and warn for approaching enemy ships or aircrafts.
  • For detecting and ranging enemy targets even at night.
  • To drop bombs on aircrafts, ships or cities at night or under poor visibility conditions.