How Accurate Are the Results of Ground Penetrating Radar?
Ground-penetrating radar is highly accurate. Under typical cemetery conditions, Sentry Mapping’s GPR pinpoints a burial center within about ±6 inches and estimates depth within ±10 percent. Results depend on soil, moisture and grave materials, but high-frequency antennas and precision GPS let us document virtually every grave without disturbing the ground.
Ground penetrating radar (GPR) is one of the most accurate, non-invasive tools for cemetery mapping. In controlled field tests and hundreds of Sentry Mapping projects, our 400–900 MHz antennas routinely locate the center of a casket, vault or soil disturbance to within ±6 in horizontally and predict depth within ±10 percent.
Accuracy ultimately depends on site conditions. Dry, sandy or loamy soils transmit signals best, while heavy clay, high moisture or dense roots can attenuate them. Even when wood coffins have collapsed, the back-filled trench and any metal hardware still produce a distinctive hyperbola pattern. Our technicians adjust antenna frequency, line spacing and survey speed to suit each cemetery’s soil, topography and burial construction, extracting the clearest data possible.
After scanning, every subsurface hit is tied to centimeter-level GPS and imported into our cemetery GIS mapping workflow. You receive a printed master map and an interactive, searchable web map on Chronicle cemetery management software, so staff and visitors can locate graves instantly with a phone.