Ground penetrating radar (GPR) uses electromagnetic waves to image subsurface conditions, without drilling or probing. It can be used to identify buried pipes, voids and other structures in concrete and soils. It is a non-invasive and cost-effective method, suitable for a variety of applications such as archaeology, geology, environmental studies and civil engineering.
In general, gpr survey are done before a construction project starts and can help prevent costly mistakes such as hitting utility lines that can cause fires or electrocuting people. It can also alert you to any unexpected obstacles like abandoned or unauthorized lines that may get in the way of your building project.
Introduction to GPR Survey: Exploring Ground Penetrating Radar
During a GPR survey, an electronic antenna sends radio waves into the ground and measures the time it takes for them to return to the surface. This information is then processed to produce 2D or 3D images of underground objects. The GPR system can be mounted on a cart, vehicle or hand-held, depending on the type of survey and environment.
GPR data can be displayed graphically as plan-view maps or cross-sections, with or without interpretation. For example, a single line of GPR data might be “sliced” into 6 or more depth segments to display different parts of the crypt in a historic cemetery (figure below). Often, GPR surveys are conducted along with a standard topographical survey. This provides context and helps to relate the utilities data back to the topographical survey results. It’s important to understand the limitations of gpr survey so that you can decide if it’s the best option for your job.