Question

Explain the principle and working of RADAR with a neat block diagram.

Answer 1

Hint : A radar system uses high-speed electromagnetic waves to determine location, velocity, direction, and the elevation of objects. It transmits electromagnetic energy and analyses the energy reflected back to it.

Complete step by step answer

Let us look at the block diagram of the working of RADAR system. It consists of an antenna, duplex switch, receiver, cathode ray indicator, modulator, master clock, transmitter, scanner.
Working of each component:
-The radar signal is generated by the transmitter and radiated into space by the antenna.
-The master clock is used to coordinate the actions of transmitter, receiver, and indicator, to make sure they are synchronised.
-The modulator is used to amplify the pulses to sufficient amplitude to operate the transmitter.
-The RF pulse generator is used to convert the modulator pulse into RF pulse.
-The antenna is used to transmit the pulses and receive them back from the target.
-The scanner is an electro-mechanical system, used to scan the space for targets by sending signals and moving the antenna in the required directions.
-The receiver is used to amplify and demodulate the received signal.
Cathode ray indicators are used to indicate the echo signals and the coordinates of the target.
Basic principles of RADAR:
-Reflection of electromagnetic rays: The electromagnetic rays are reflected back, if they meet an electrically leading surface. This implies that there is an obstacle in its way.
-Electromagnetic energy travels through air at a constant speed, at approximately the speed of light. This constant speed allows the determination of the distance between the reflecting objects and the radar site by measuring the running time of the transmitted pulses.
-Using the RADAR antenna, the energy can be transmitted to the desired direction, implies that the direction of the target can also be determined.

Note
RADAR is used in many fields. It includes:
-Air traffic control: It is used to locate the traffic and ensure safety near airports.
-It is used in target detection management in air defence.
-It is used in remote sensing to locate sea ice for smooth travel through sea, locate objects in space, also for observing weather conditions.
-It is also used to monitor meteors, detect satellites etc.