The distance is determined from the
running time of the high-frequency transmitted signal and the
propagation speed C0. The actual range of a
target from the radar is known as slant range. Slant range is the
line of sight distance between the radar and the object illuminated
while ground range is the horizontal distance between the emitter
and its target and its calculation requires knowledge of the
target's elevation. At this this one, however, to and way back must
taken into account. Therefore the following formula arises for the
slant range:
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C0 = speed of light = 3�108 m/s
t = measured time [s]
R = slant range [m] |
The Distances are expressed in
kilometers or nautical miles.
Derivation of the equation
Range is the distance from the
radar site to the target measured along the line of sight.
|
v = speed
s = range
t = time |
Figure 1: principle of radar |
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The factor of two in the formula comes from the
observation that the radar pulse must travel to the target
and back before detection, or twice the range. |
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Where C0= 3 x 108 m/s, is the
speed of light at which all electromagnetic waves propagate. |
If the respective running time t is known then can be calculated the distance R with help of
this equation between a target and the radar set.
