Abstract: An improved non-obtrusive weapon detection system and method used in discriminating between a concealed weapon made of a ferromagnetic material. The system provides a high probability of detection of hand guns and other types of weapons with a low false alarm rate. The detection of the weapon is accomplished by measuring a total electromagnetic field. The total field being the sum of an incident electromagnetic field and an electromaetic field scattered from the object. The system uses a magnetic field transmitter, which transmits a low intensity electromagnetic signal. The electromagnetic signal illuminates a volume wherein the weapon, called a target, may or may not be carried by a person. The electromagnetic signal is in a form of a sudden steplike change in a constant magnetic field, called a “time-domain” excitation. The waveform or step pulse of the time-domain excitation is called a Heaviside step pulse.