RADAR fundemental




The basic idea behind Radar (Radio Detection And Ranging) is very simple: a signal is transmitted, it bounces off an object and it is later received by some type of receiver. Echo (to determine how far away) and Doppler Shift (to determine how fast is moving) technologies used. However radars don’t use sound as a signal. Instead they use certain kinds of electromagnetic waves called radio waves and microwaves which can travel far, are invisible to humans and are easy to detect even when they are faint. A basic radar system is split up into a transmitter, switch, antenna, receiver, data recorder, processor and some sort of output display. Everything starts with the transmitter as it transmits a high power pulse to a switch which then directs the pulse to be transmitted out an antenna. Just after the antenna is finished transmitting the pulse, the switch switches control to the receiver which allows the antenna to receive echoed signals. Once the signals are received the switch then transfers control back to the transmitter to transmit another signal. The switch may toggle control between the transmitter and the receiver as much as 1000 times per second. Any received signals from the receiver are then sent to a data recorder for storage on a disk or tape. Later the data must be processed to be interpreted into something useful which would go on a display.
Radar is an acronym for “radio detection andranging” that is an electronic system for transmitting electromagnetic signals and receiving echoes from objects of interest (targets).
A radar system usually operates in the ultra-high-frequency (UHF) ormicrowave partof the radio-frequency (RF) spectrum, and is used to detect theposition and/ormovement of objects.