Patent ID: 7683822

Claim:
A method for remotely detecting potentially threatening metal items that comprises the following: scanning a space under surveillance with electromagnetic radiation; detecting metal items contained in this space based on an output signal of a receiver of reflected signals; employing a continuous frequency-modulated ultra high or super high frequency signal as electromagnetic radiation; storing, in a processor, codes of amplitudes of output signals of said receiver of reflected signals for all radiation directions during the initial scanning period when no potentially threatening metal items are allowed in a scanning sector; recording, in the processor, an event of detection of potentially threatening metal items during subsequent scanning periods if one of the following two comparison conditions holds for some radiation direction: A i >A 0 +Δ or A i <A 0 −Δ, where A i is a code of an amplitude of the signal at the output of receiver of reflected signals during any scanning period after the initial one for any radiation direction; A 0 is a code of an amplitude of the signal at the output of said receiver of reflected signals during the initial scanning period for the same radiation direction for which the code A i was obtained; Δ>0 is a tolerance of the deviation of the code A 0 .