Ground Penetrating Radar, or GPR sends radar waves (radio waves) into the ground using a series of antennas inside our GPR unit. These radio waves are sent into the ground through an antenna as we move our GPR along the ground surface. These waves are reflected off of an object underground, such as a underground storage tank, septic tank, or utility and travel back up through the earth and are received by another antenna. The speed and strength of this return signal is interpreted by our on-board computer which then transfers the collected data into an image on our computer screen. This is how we are able to “see” objects buried below the ground in real-time!
Through GPR technology we are able to locate non-conductive, non-metallic utilities and objects that standard electromagnetic locating can not find such as fiber optic, storm water, drainage, septic tanks, leach fields, and underground storage tanks. GPR can also be useful for determining depth to bedrock and the water table at your site. This technology is also suited for use indoors to search for the location and depth of sewer pipes, electrical conduits, rebar, mesh, post-tension cables, and more. This information is beneficial to contractors, plumbers, electricians, excavators, and builders.
GPR technology does have its limitations. Accessibility, weather, topography, and other site conditions may prohibit the feasibility of using GPR. Generally, wet clay soils can act as a barrier preventing our radar signal from penetrating deeper than the wet clay layer. Our standard GPR works well from depths down to about 10 – 12 feet. We often use GPR in addition to other locating methods when identifying utilities at your site. We will discuss with you the feasibility of GPR at your site and schedule around weather and other limiting factors to provide you with the subsurface information you need to proceed with your project.