Metal Detector Image Scanner Separation of Metals

If the image scanner is in the category of metal detectors or metal detectors or Ground Handy Radar or GPR or Ground Penetrating Radar or underground image detectors during testing and searching it must be capable of distinguishing and discriminating different types of metals in depth And especially  it should capture gold in depth and separate and discriminate because the image scanner  which is in the category of metal detectors uses the principles of Low Frequency Radar circuits for Separation and Discrimination