Ground radar survey is an advanced geophysical technique that uses electromagnetic radiation within the MF, HF and VHF radio spectrum to map below-ground lithology and locate buried objects. It is non-intrusive and can be used to detect pipe, rebar, rock and other construction materials as well as voids and anomalies. It is also a useful tool in archaeology for locating artifacts without digging.

GPR systems utilize an antenna system with a digital control unit to transmit radar pulses into the subsurface for measurement and analysis of the return signals. The signal amplitude variations, wave velocity-dependent travel time, and geometry of reflectors are mapped to produce radar traces that can be interpreted for estimating depth to buried targets.

Exploring the Uses and Benefits of Ground Radar Surveys

The choice of antenna frequency for a GPR survey impacts both the resolution and penetration depth. The higher the frequency, the more detail is available in the data; however, it will have less penetration depth.

The most effective GPR survey is one that is performed under ideal conditions. Achieving good results is dependent on the electrical conductivity and permeability of the soil as these factors can greatly affect the penetration depth and interpretation of the radar data. For instance, the water content of a site can significantly raise the dielectrical properties of the material and therefore reduce the penetration depth of the radar waves. This can also make interpreting the radar data more difficult, especially in heterogeneous rocky or clay soils. This is why careful selection and calibration of the GPR equipment is essential.