Ground-penetrating radar (GPR) is a geophysical method that uses radar
pulses to image the subsurface. It is a non-intrusive method of surveying the
sub-surface to investigate underground utilities such as concrete, asphalt,
metals, pipes, cables or masonry. This nondestructive method uses
electromagnetic radiation in the microwave band (UHF/VHF frequencies) of the
radio spectrum, and detects the reflected signals from subsurface structures.
GPR can have applications in a variety of media, including rock, soil, ice,
fresh water, pavements and structures. In the right conditions, practitioners
can use GPR to detect subsurface objects, changes in material properties, and
voids and cracks.