Ground-Penetrating Radar (GPR)

Ground-penetrating radar (GPR) is a geophysical technique that transmits short pulses of high-frequency electromagnetic energy (typically 10 MHz to 2.6 GHz) into the ground and records the reflections from subsurface interfaces where the electrical properties of materials change. The resulting radargrams reveal the location, depth, and geometry of buried objects, layers, and voids without physical excavation. How GPR worksa GPR system consists of a transmitting antenna that sends radar pulses into the ground, a receiving antenna that detects reflected signals, and a control unit that records and displays the data. Higher frequency antennas provide finer resolution but limited depth penetration, while lower frequencies penetrate deeper but with coarser resolution. Depth penetration ranges from less than one meter in conductive materials like wet clay to over 30 meters in dry sand or ice. ApplicationsGPR is used for utility detection (locating buried pipes, cables, and conduits), concrete inspection (finding rebar, voids, and delamination), archaeological investigation (mapping buried structures and artifacts), road and pavement assessment, environmental site characterization, and glaciology. It is a standard tool in construction, engineering, and forensic investigation. GPR provides a unique non-invasive window into the subsurface, enabling rapid, non-destructive surveys that reduce excavation costs and protect buried infrastructure. Its versatility across engineering, archaeology, and environmental applications makes it an essential field survey tool.