As a result of magnetization by the Earth’s magnetic field, a metallic
material can create distortions in the local geomagnetic field along
each of its three orthogonal directions. Magnetic anomaly detection
(MAD) is the use of such phenomenon by magnetic sensors because of the
passage of a metallic material nearby a stationary sensor or when a
sensor is mounted on a moving platform to sense a stationary target. The
MAD method has been proven to work aboard in traffic surveillance,
vehicle parking , sea mine hunting, security checking, unexploded
ordnance discrimination, subsea cable and underwater vehicle detection .
