Patent ID: 8102260

Claim:
A method for determining a presence of a threatening object, the method comprising: acquiring raw magnetic data associated with a magnetic response of a ferrous object within a detection range; performing at least two different analysis methods independent from each other to extract a plurality of features from the raw magnetic data, wherein each individual feature of the plurality is a different repeatable characteristic that is characteristic to a same class of detectable ferrous objects, wherein at least one feature of the plurality is a symmetry coefficient representing symmetry of the ferrous object; comparing the plurality of features with previously stored features from a database, the database having been populated with the previously stored features that are related to a variety of different known objects, wherein at least one of the variety of different known objects is classified as a non-threatening object and at least another of the variety of different known objects is classified as a threatening object; determining that the ferrous object is a threatening object when the plurality of features extracted from the raw magnetic data are determined to at least substantially match the previously stored features of the threatening object; and determining that the ferrous object is a non-threatening object when the plurality of features extracted from the raw magnetic data are determined to at least substantially match the previously stored features of the non-threatening object.