Ground-Penetrating Radar (GPR)
Underground Services Detection Survey will perform suitable electromagnetic tests, for detecting underground, the GPR technique exploits the reflection of high – frequency electromagnetic pulses generated and transferred into the ground. This way, it enables one to detect dielectric discontinuity existing in the material through which the pulse travels. It is the contrast in the dielectric permittivity at the layer boundaries between the bulk medium and the buried targets that causes reflection: the greater the difference in dielectric permittivity, the greater of coefficient of reflectivity. These differences are often associated with change in textural lithology, porosity and density of material, but especially with water content. Water content mainly controls the signal energy, causing a loss in the wave energy, and changes in water content may produce abrupt jumps in relative dielectric permittivity. The transmitting antenna broadcasts over the ground electro-magnetic pulses at a certain frequency, the pulse spread into the ground at a velocity typical of that terrain. When the transmitted wave encounters a discontinuity in the dielectric properties , a certain amount of energy is reflected and picked- up by a receiving antenna, the remaining part of the wave continues to travel towards deeper areas
The GPR survey will carry out to detect , metallic and non-metallic interferences at Work Site covering the extent of soil below the natural ground level of the survey area, as a minimum, the survey shall determine location of underground piping, conduit, electrical wiring, concrete or a contaminated substance located below ground that could cause loss or injury.