Magnetic prospecting in the ground is based on the measurement of the Earth’s magnetic field and its local variations caused by the presence of natural (or manmade) objects. These variations depend on the magnetic susceptibility of the buried objects and the background Earth’s magnetic field.

The magnetic susceptibility is a material property that describes the change in magnetization of an object due to an external magnetic field, hence creating its own secondary magnetic perturbation field. Magnetometers detect all objects with high magnetic susceptibility. The discrimination between objects of different size is based on the amplitude and shape of the measured magnetic anomalies.

Magnetic exploration is typically used for buried waste location, metallic ore characterization or archaeological studies.