Live Weather Radars

The Doppler radar uses what is typically referred to as the Doppler Effect or Doppler shift to successfully measure the velocity of specified targets radially by the use of a particular beam generated from its antenna. The received frequency is either shifted up or down by the Doppler Effect based on the current velocity of the specific target within the beam range allowing the radar to record an accurate measurement of the particle velocity of the target.

Velocity measurements is one of the results produced by Doppler radars as they can be either Continuous Wave, in which the Doppler wave will produce only velocity outputs. They can be Coherent Pulsed as seen with the introduction of digital technology. Such radars were seen as a combination Doppler technology to specific pulse radars to achieve accurate information respective to particle velocity.

Doppler radars can also be observed as Frequency Modulated which was developed based on the previous technology used by the earlier Continuous Wave radars which allows the radar to sweep transmitter frequencies to encode the information received to accurately determine the particle range. These radars however are only able to process and monitor one target at a time which limits their use.

This Doppler Effect used by the Doppler radar was named after Christian Doppler an Austrian physicist who in the year 1842 stated that the Doppler effect is that effect produced by a moving source of waves during which there can be an apparent increase or decrease in the known frequency of those waves by an observer towards whom the source is either approaching resulting in a upshift in the wave frequency or downshift in the event that that source is receding.

Such notable changes in frequency change are however not actual in respect to the frequency of the existing wave, but rather are merely interpreted as such by the observer as the actual frequency of the waves generated by the source does not change. This analogy can be easily observed in the instance of an approaching, and passing fire truck or similar emergency vehicle with a siren.

As the vehicle nears the observer’s position the wavelength are seen as smaller and will indicate a higher frequency as opposed to the observer as a further distance with the source moving away which will indicate a longer wavelength and lower frequency.

This Doppler Effect was successfully used in weather forecasting radars to closely monitor and predict specific weather patterns by closely observing climatic changes within the atmospheric conditions relative to the areas targeted and is also seen in providing information in areas of astronomy respective to electromagnetic waves produced within the Solar Galaxy by moving stats and planets.