System and method using magnetic anomaly field magnitudes for detection, localization, classification and tracking of magnetic objects

A method of detecting, localizing and classifying magnetic objects, comprising the steps of

• providing at least four triaxial magnetometer (TM) sensors with each of said TM sensors having X,Y,Z magnetic sensing axes, said TM sensors arranged in a three-dimensional array with respective ones of said X,Y,Z magnetic sensing axes being mutually parallel to one another in said three-dimensional array, said three-dimensional array defining a geometry that forms at least one single-axis gradiometer along each of said X,Y,Z magnetic sensing axes;
• generating scalar magnitudes of a magnetic anomaly field measured at each of said TM sensors;
• comparing said scalar magnitudes to at least one threshold value;
• determining distance to a source of said magnetic anomaly field using said scalar magnitudes when said at least one threshold value is exceeded;
• and
• determining a magnetic dipole moment of said source using said distance.