Structural Radar Imaging explains how
ground penetrating radar works

Ground penetrating radar is a non-destructive geophysical method that produces a continuous cross-sectional profile or record of subsurface features, without drilling, probing, or digging. Ground penetrating radar (GPR) profiles are used for evaluating the location and depth of buried objects and to investigate the presence and continuity of natural subsurface conditions and features.

The ground penetrating radar unit has a sending antenna which sends out pulses of electromagnetic energy, and a receiving antenna, which picks up those pulses when they reflect off objects underground. The returned pulses can be used to construct an image of what is underground, because they will vary depending on the depth and composition of buried objects. This real-time image allows for a real-time on-site interpretation and the potential of a detailed, spatially specific
GPR investigation.

The depth range of GPR is limited by the electrical conductivity of the ground, the transmitted center frequency and the radiated power. As conductivity increases, the penetration depth also decreases. This is because the electromagnetic energy is more quickly dissipated into heat, causing a loss in signal strength at depth. Higher frequencies do not penetrate as far as lower frequencies, but give better resolution. Optimal depth penetration is achieved in ice where the depth of penetration can achieve several hundred feet. Although, the GPR equipment that SRImaging actively uses can penetrate the ground up to 10' deep

Ground penetrating radar antennas are generally in contact with the ground for the strongest signal strength; however, GPR air launched antennas can be used above
the ground.

SRI conducts ground penetrating radar surveys

SRI conducts ground penetrating radar surveys using antennas with various frequencies. Depths of ground penetrating radar (GPR) can be as deep as 30 to 40 feet (10 to 15 meters) in sandy or silty soils, using a low frequency ground penetrating radar antenna. A higher frequency ground radar antenna can examine the near surface, from 0 to 10 feet (0 to 3 meters)
GPR is a noninvasive geophysical tool that helps to detect large changes in physical characteristics of the soil. It responds to abrupt boundaries. GPR is used for determining depths to soil layers, water table, cobble, and bedrock., in great detail.

SRI, Inc. can conduct ground penetrating radar (GPR) scanning of concrete to locate rebar, pipes, tension bars, and conduits in concrete structures. Our scanning can also detect voids within concrete slabs and under concrete slabs.

Our ground penetrating radar scanning can inspect concrete walls, concrete floors, slabs, airport runways, tunnels, abutments, dams, and garages. Asphalt roads and surfaces can also be scanned.

Whether you need ground penetrating radar scanning, consulting, or on-site training, SRI, Inc. provides the total solution to all your ground penetrating radar needs.

In addition to evaluating the condition of concrete, GPR can quickly locate and document the position of post tension cables, conduit, pipes, and rebar buried inside a concrete slab.  The portability and ease of operation of modern GPR systems allows the operator to move easily about the job site and to record a large amount of data in a short period of time.

The beauty of GPR is that it is non-invasive, relatively inexpensive, and can be used in a variety of ways -- there are hand-held units, down hole units, units that can be dragged behind vehicles, and even used from aircraft and satellite. It has the highest resolution of any subsurface imaging method (sometimes with resolutions of one centimeter), and is far safer than x-ray technology.