Geophysical survey can be used to detect foreign objects in the ground, for example in infrastuctural and archaeological projects or landfill investigations. Foreign objects in the subsurface can usually be detected because they have different properties than the surrounding material. Possible applications of geophysical techniques in the research of foreign objects in the subsurface are:
detection of cables and pipes,
detection of foundation piles,
detection of metal objects such as oil barrels and tanks,