Section 7 - Gpr Concepts; Theory; Hyperbolas - SPX Radiodetection RD1100 Operation Manual

GPR Concepts

Section 7 - GPR Concepts

7.1 Theory

Ground Penetrating Radar (GPR) technology uses radio waves to image objects in the
subsurface. GPR systems emit high frequency radio wave pulses and detect the echoes that
return from objects within the subsurface. Echoes are produced when the target material is
different from the host material (eg. PVC pipe in gravel)

7.2 Hyperbolas

The GPR display shows signal amplitude versus depth (time) and sensor position along a line.
This is called a "Line Scan". Since radar energy radiates in a 3D cone shape rather than a thin
beam, a hyperbola (or inverted U) is the GPR response from a small point target like a pipe,
rock, or a tree root. The radar wave hits the object before and after going over it and forms a
hyperbolic reflection that can appear on the record even though the object is not directly below
the radar:
RD1100 Operation Manual 28 © Radiodetection 2016