what is a doppler rader and what it does?

Question

just for science, just for my dumb friend, help his stupid *** please.

Answer 1

A radar is nothing more than a large radio transmitter and receiver.

The radar sends out a single radio frequency (RF) pulse, and then switches to receive. Any power near the same frequency that it transmits at reflected back to the receiver from a target will then be received. The time lag between transmit and receive determines the distance to what ever caused the RF power to be reflected back. The direction is usually determined by a directional antenna and the direction the antenna is pointing is used as the direction to the target. The amount of power returned from the target is also measured by the radar set.

A Doppler radar. not only measures the distance, direction, and power returned but also the slight shift in frequency that is caused by a moving target (in the case of weather radar this is rain drops) which is called the Doppler affect. This can be is analyzed to determine two things whether the target is moving toward or away from the radar and what speed it is moving toward or way from the radar. Only the portion of the movement that is toward or away from the radar can be measured. Any target that is moving at right angles to the radar beam shows no velocity no matter how fast it is going!

The amazing fact is all of this happens a lot fast than I can explain it. Most modern Doppler radars send out and analyze over a thousand pulses per second.

This explanation is a much simplified version, the modern Doppler weather radar is very complex and the information is a quantum leap over earlier weather radars.

Answer 2

Doppler radar is more correctly called pulse doppler radar. It sends out two quick pulses and measures the time it takes the signals to return. The difference will tell the operator how far away the targets are, what direction they're moving and how fast. This difference will show up as different colors on the screen. Since the frequency is high enough to detect things as small as raindrops it is an excellent tool for studying meteorological phenomena like storms and weather fronts.

Answer 3

The main difference between a Doppler radar and other radars is the additional information we get about the speed of the target.Only the speed of targets which approach the radar or goes away from the radar can be estimated.You may be knowing that the continuous whistling sound of a train varies(due to frquency change) when it is fastly approaching us.This is due to Doppler effect and this principle is used in Doppler radars.The frequency changes due to the movement of the target is analysed by the radar and the speed is calculated.This will be very useful in finding out the speed of a storm(hurricanes and cyclones) when they approach the radar.Cloud movements to and away from the radar can also be studied.Vertical movement of air currents inside a thunder cloud can also be analysed.