Despite our increasing ability to detect and monitor objects that exist on land, sea, around buildings or in space, our ability to detect objects beneath the ground has not improved significantly. When it comes to attempting to locate a buried and forgotten pipe, telling the extent of a sink hole or assessing the quality of infrastructure we still often resort to digging or drilling holes. This presents a huge economic and societal cost as road networks are dug up, oil wells are dry or brown-field land is left undeveloped. Existing techniques are all fundamentally limited in either their sensitivity (classical microgravity), their penetration (Ground Penetrating Radar) or their cost (seismic).