Magnetic surveys can provide information useful for the following applications:

Magnetic surveys provide a cost-effective means for quickly providing whole-site or specific-area investigations.  Magnetometers are highly portable, therefore, surveys can be conducted over uneven terrain.

A magnetic survey accurately measures the earth's magnetic field.  Objects containing ferrous material create local perturbations in the earth's field. 

A magnetic gradiometer consists of a magnetometer equipped with two sensors.  The sensors are placed in a vertical orientation to measure the vertical gradient in the earth’s magnetic field, or they can be placed in a horizontal configuration to measure the horizontal gradient.  A gradiometer is ideally suited for detection of shallow ferromagnetic material because the gradiometer accentuates the signal from objects which are at shallow depth while ignoring distant features.  In a gradiometer survey, no corrections are needed for diurnal changes in the earth’s magnetic field because the diurnal changes affect both sensors equally.