GPR uses the principle of scattering of electromagnetic waves
The basic operating principle for GPR is the radiation of electromagnetic wave into the subsurface
Radiation of electromagnetic waves from a transmitting antenna, the wave spread out and travel downward at a velocity until it hits an object & the scattering from the object is detected by a receiving antenna
The specific travel velocity of electromagnetic waves is determined primarily by the permittivity of the material
Different velocity for different between materials with different electrical properties
A signal passed through two materials with different electrical properties over the same distance arrive at different times
metallic and non-metallic utilities ( Conductive & Non Conductive)
Buried Elements For example Cables-Power, Fiber- Pipes- structures
Voids in Concrete
Voids in Roads
Different frequencies antenna are used for different depths.
Uses short impulse of high frequency radio waves. Energy radiated into the ground is reflected back to the antenna by features having different electrical properties. Low frequencies give better penetration.
Depth of penetration may be limited to only a few feet in wet, clayey soils.
