How does doppler radar work?

Question

I would like to know how the doppler effect is used in weather.

Answer 1

This link will give you a complete tutorial on it. Good luck.
http://apollo.lcs.vcs.edu/classes/remote/lecture_notes/radar/doppler/

Answer 2

Doppler radar uses sound waves that contain energy, and bounces back to the antenna. It depends on the frequency of the target up or down motion through velocity measurement. It the faster an object falls (such as thick raindrops or hail) will reflect higher because they have more energy motion when coming down.

How does the Doppler exactly work? For example: There is a train approaching in the distance, you don’t see it, but you hear it blowing its horn. As the train approaches closer the horn gets louder and louder. This is called the Doppler Effect. The Doppler Effect measures radial velocity in the direction line of sight. The oscillation of the Doppler Effect determines the wind velocity, and this is how Doppler radars detect tornadoes. It uses the different motion direction of winds. Winds are negative when moving toward the radar and positive when moving away.

These combinations put into effect makes is identify tornadoes by rotation. If you have a small area of positive radial velocity adjacent to negative radial velocity, then a tornado is possible. Echo tops can be detected on radar. Echo tops are the measurement of how tall a storm is, but it measure how high the precipitation is falling from the storm. This is a very good way to assess a storm’s updraft strength. This can tell you the hail potential and the possible size. A rapid drop in echo tops might indicate a strong downburst maybe occurring (winds 75 mph or more).

Answer 3

Weather radar works by sending out rf (radio frequency) energy and records the reflection back from weather. NOAA weather radar works in two modes, clear air and rain mode. The modes are different because clear air does not reflect as much as rain does, so clear air modes uses a different scan rate and resolution. The Doppler effect of the reflection indicates in what direction the weather is moving. Reflections moving towards the radar are higher in frequency and reflections moving away from the radar are lower in frequency. Computers take all this information and can paint a complete picture of the weather surrounding the radar.

Answer 4

Doppler radar uses a specified frequency of sound. They take this frequency and send it out in a direction. When it hits something the sound will bounce back. Since distance affects how high or low a sound is percieved to be, you can then tell the distance and dimensions of an object.

Answer 5

Doppler radar can tell if something is moving toward it or moving away from it by radiation shifts.

Answer 6

Here is a complete discription with diagrams of how Doppler works and how it is used by the NWS
http://www.srh.noaa.gov/srh/jetstream/remote/doppler.htm