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

NOTE: We've guessed that you're not using a client that supports colored tables and have tried to compensate. Low graphics mode looks much better on clients that do... we recommend switching to Netscape 3.0 or Microsoft Internet Explorer.
.
Locating a Target
angles and distances used

The radar needs 3 pieces of information to determine the location of a target.

The first piece of information is the angle of the radar beam with respect to north; called the "azimuth angle".

The second is the angle of the beam with respect to the ground; called the "elevation angle".

The third piece of information needed is the distance (D) from radar to target.

Distance is determined by measuring the time it takes for the pulse to make a round trip from the radar to the target and back using the relation distance = (time) * (velocity). The velocity is the speed of light, the speed at which the pulse travels (c). Since the pulse has to travel to the target and back, the total distance is 2D. If t is the time it takes, then 2D = ct or D = ct/2. Using the calculated distance, azimuth angle and elevation angle, the exact location of the target can be determined.



clear air returns
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.

scanning modes