A Comprehensive Guide to Ground Penetrating Radar (GPR)

In the pavement industry, GPR is widely used for locating utility lines, monitoring pavement and runways, locating reinforcement bars, changes in layer thicknesses and voids, as well as moisture determination.

Ground Penetrating Radar (GPR) is a radar system that is used to image the subsurface. The huge advantage of GPR is that it allows crews to safely conduct investigations in a non-intrusive way. It is quick to deploy and easy to operate. But have you ever wondered GPR works?

Ground Penetrating Radar involves passing a transducer (transmitter/receiver) over the ground surface. The transmitter emits low powered radio energy and reflections from material boundaries and embedded features like metal or voids are recorded by the receiver. The results can be viewed on-screen and recorded to disk.

The sampling occurs so rapidly that the collected data that it essentially forms a continuous cross section, enabling speedy examination of thickness and condition over large areas. GPR works effectively on rough surfaces and through multi-layered media. However, penetration and resolution are impeded when ‘seeing’ through highly conductive materials such as wet clays and soils.

Figure 1: Ground penetrating radar (GPR)

We explain the GPR in a full length guide that can be downloaded for free via https://www.pavement.com.au/ground-penetrating-radar