Charles Machine Works Inc The 2150GR250 ユーザーズマニュアル

2150GR Ground Penetrating Radar 

054-139 - Rev. 1

 
 

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The main targets when performing  utilities investigations with the 2150GR consist of either 
extended structures (such as an interface between layers, pipes parallel to the investigation 
direction etc.) or quite small structures (such as pipes perpendicular to the investigation 
direction, cavities and rocks etc.). 

Fig. 7-1 shows how a flat interface gives rise to a flat trace while a small structure such as a 
pipe produces a hyperbolic trace. This is because the echoes form the flat plane at different 
values of x take the same time to reach the 2150GR. For the pipe, however, the echoes from 
its sides take a longer time to reach the 2150GR than the echoes from its top surface. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 The aperture of a hyperbola depends on various factors: 

o

  As the propagation speed in the medium increases (v

), the ratio between the flight 

time of the outwards and return signal twt relative to echoes originating from lateral 
points and the twt relating to the top surface of the target decreases. Therefore the 
hyperbola widens with higher propagation speed, v

. 

o

  With increasing depth of the target, the ratio between the twt relating to the echoes 

from the side points and the twt relating to the top surface of the target decreases. 
Again, the hyperbola widens with increasing target depth. 

2150GR 

2150GR 

2150GR 

2150GR 

Pipe 

Interface