The need for techniques that provide rapid area coverage and detailed subsurface imaging to evaluate historical sites without intrusive surveys naturally leads to harnessing the power of ground penetrating radar (GPR).

Field archaeology with drones or GPR cart

Ground penetrating radar or GPR is a system used in geophysics to scan, map and record information about the earth's subsurface. Archaeologists have used this technical procedure for many years, and it is also common in other scientific disciplines such as environmental studies, geology and even civil engineering.

Archaeological geophysics includes methods of collecting data that allow the field archaeologist to image and map underlying archaeological features that are otherwise impossible to detect by traditional field methods. Archaeologists can take advantage of physical and chemical changes in the soil in relation to the presence or absence of buried objects. Using highly sensitive instruments, the specialized technician can measure, map and interpret the data signals received by the GPR system into useful information for excavation planning.

Non-invasive examination

The main advantage of ground penetrating radar is that it provides a non-invasive and non-destructive way to gather information about the nearby subsurface. Large sites with hidden remains can be viewed and analyzed efficiently and accurately while preserving the site.

GPR maps provide useful primary survey data that can be used to establish excavation sites or even identify sensitive areas where cultural remains, such as cemeteries, may be found. These areas may require a special extraction process, and the information can guide archaeologists to avoid disturbance or destruction of these sites.

The sedimentary layers and buried artifacts have a specific physical and chemical composition. This affects the rate of propagation of electromagnetic waves (electrical conductivity and magnetic permeability). Differences or variations in the received waves indicate the presence of objects, cavities, changes in physical properties, etc. Patterns in subsurface imaging indicate underlying archaeological features such as architecture or artifacts.