Can ground‑penetrating radar still detect graves that are over 100 years old?
Yes. High-frequency ground-penetrating radar can still pick up century-old graves in most soils because disturbed soil layers, vault remnants, or voids remain detectable. While resolution fades as coffins decay, Sentry Mapping’s specialized GPR and GIS workflow regularly finds 19th-century burials and older, as long as site conditions (soil, depth, moisture) are reasonable.
Ground-penetrating radar cemetery mapping by Sentry Mapping routinely detects graves that are 100, 150 or even 200 years old. The radar does not “see” bones; instead it registers contrasts caused by disturbed back-fill, collapsed voids, stone or metal vault fragments, and any remaining coffin hardware. Those contrasts persist long after organic material has vanished, so a knowledgeable technician can still interpret the hyperbolas in the scan.
Several factors affect clarity:
- Soil type – dry, sandy or loamy soils transmit radar waves best, while heavy clay or saturated ground can attenuate the signal.
- Burial construction – concrete vaults, metal coffins or brick crypts create stronger reflections than simple wooden boxes, but even vault-less graves leave a trench signature.
- Depth and surface change – graves buried within the typical 3–6 ft range remain within effective reach of Sentry’s 400–900 MHz antennas; heavy grading or tree roots may mask shallower features.
In a recent project our team mapped a 150-plus-year-old rural cemetery with no surviving records. GPR located dozens of 1800s burials that had lost their markers, allowing staff to mark them permanently and avoid reselling occupied plots. The results were delivered as a printed master map and an interactive GIS web map with searchable plots on Chronicle cemetery management software—all at no annual subscription cost.
If you need to confirm historic burials, request a free cemetery mapping estimate here.