GPR ( Ground Penetrating Radar )

ClearView Geophysics Inc., carries out GPR (Ground Penetrating Radar) surveys for a wide variety of applications:
tank locates - where Geonics EM61 survey is not feasible (surface clutter, multiple        targets, etc.)
depth to water table
depth to bedrock
pipe locates
stratigraphic mapping
contaminant mapping (in special cases)
reinforced concrete testing
road-bed studies

Note that GPR works best in low conductivity areas. Conductive materials (e.g., clay) attenuate the GPR signal to the point that very little depth penetration is achieved. Penetration is greatest in unsaturated sands and fine gravels.

GPR can also be used to detect contaminants, if the conditions are right. The reflection delay time is controlled by the dielectric properties of the material. The signal velocity (m/ns) is approximately equal to one third the value of the dielectric constant. Some contaminants have different dielectric properties compared to the host geology. For example, GPR signals travel at 0.01 m/ns through sea water compared to 0.06 m/ns through clean, saturated sand.

The penetration depth of the instrument is also dependent on the chosen base frequency. The higherthe frequency, the less the penetration. The trade-off is that the lower frequencies lose target resolution. Typically, 100 MHz and 50 MHz are used for bedrock detection, 500 MHz and 250 MHz antennae are used for tank locates, and 1000 MHz is used for rebar checking.

Call ClearView Geophysics Inc. to discuss whether this method is ideal for your site specific case.