WW2010
University of Illinois

WW2010
 
  welcome
 
> online guides
 
  archives
 
  educational cd-rom
 
  current weather
 
  about ww2010
 
  index

Online Guides
 
  introduction
 
  meteorology
 
> remote sensing
 
  reading maps
 
  projects, activities

Remote Sensing
 
  introduction
 
> radars
 
  satellites

Radars
 
  introduction
 
> radar basics
 
  imagery
 
  velocity patterns
 
  applications

Radar Basics
 
  radar signals
 
  wave properties
 
  signal scattering
 
  wavelength effects
 
  ray paths
 
  clear air returns
 
  target location
 
  scanning modes
 
> radial velocity

User Interface
 
  graphics
> text

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Radial Velocity
measured by Doppler radars

Doppler radars can measure the component of the velocity of targets toward or away from the radar. This component is called the "radial velocity".

For example, at time T1 a pulse is sent towards a target and it returns a target distance "D".

2) At time T2, another pulse is sent towards the same target and returns a target distance "D+A"

The distance to target has changed from times T1 to T2, resulting in a phase shift between the two return signals, which Doppler radars are capable of measuring. By knowing the phase shift, the wavelength and the time interval from T1 to T2, the velocity the target has moved toward or away from the radar can be computed. If the target is moving sideways so that its distance relative to the radar does not change, the radar will record zero radial velocity for that target.



scanning modes
Terms for using data resources. CD-ROM available.
Credits and Acknowledgments for WW2010.
Department of Atmospheric Sciences (DAS) at
the University of Illinois at Urbana-Champaign.

Imagery