Method and system for remotely detecting metal items, for example, weapons

• US 20080106454A1
• Filed: 12/31/2007
• Published: 05/08/2008
• Est. Priority Date: 04/28/2006
• Status: Active Grant

• Current Assignee: Nikolay Danilov, Vladimir Kropotov
• Original Assignee: Nikolay Danilov, Vladimir Kropotov
• Inventors: Kropotov, Vladimir, Danilov, Nikolay
• Granted Patent: US 7,683,822 B2
• Time in Patent Office: Days
• US Class Current: 342/22
• CPC Class Codes: G01S 13/04 Systems determining presence of a target based on relative movement of target G01S13/56
• CPC Class Codes: G01S 13/88 Radar or analogous systems specially adapted for specific applications electromagnetic prospecting or detecting of objects, e.g. near-field detection, G01V3/00
• CPC Class Codes: G01S 13/887 for detection of concealed objects, e.g. contraband or weapons
• CPC Class Codes: G01S 13/89 for mapping or imaging

Abstract

The invention relates to the methods and systems for remotely detecting metal items, for example, weapons, concealed in cloths or belongings and may be used in security complexes. The proposed system contains a phased antenna array 1 radiating a continuous frequency-modulated ultra high or super high frequency signal and scanning a controlled space, a receiver 2 of reflected signals, a processor 3, a display 4, and a video camera 5. The processor 3 detects a potentially threatening metal item during any scanning period other than the initial period if one of the two comparison conditions holds for some radiation direction: A_i>A₀+Δ or A_i<A₀−Δ where A_i is the code of the signal amplitude at the output of the receiver 2 of the reflected signal during any scanning period following the initial period for some radiation direction; A₀ is the code of the signal amplitude at the same output for the same direction of radiation during the initial scanning period when no potentially threatening metal items are allowed in the scanning sector, and Δ>0 is the tolerance of the deviation of the code A₀ taking into account permissible changes in the reflected signal. Advantages of the invention: extension of the range of permissible distances to detected metal items, increased noise immunity, simplified operator activities, and increased scanning rate and reliability.

Claims

1. Method for remotely detecting metal items, for example, weapons, that comprises the following:

scanning the controlled space that may contain potentially threatening metal items with electromagnetic radiation;

detecting the presence of those items based on the output signal of the receiver of the reflected signal;

employing the continuous frequency-modulated ultra high or super high frequency signal as electromagnetic radiation;

storing, in the processor, the codes of the output signals of the receiver of the reflected signal for all radiation directions during the initial period of scanning when no potentially threatening metal items are allowed in the scanning sector;

recording, in the processor, the event of detection of potentially threatening metal items during subsequent scanning periods if one of the two comparison conditions holds for some radiation direction;

A_i>

A₀+Δ

or A_i<

A₀−

Δ

,

where

A_i is the code of the amplitude of the signal at the output of the receiver of the reflected signal during any scanning period after the initial one for any of the radiation directions;

A₀ is the code of the amplitude of the signal at the output of the receiver of the reflected signal during the initial scanning period for the same radiation direction for which the code A_i was obtained;

Δ

>

0 is the tolerance of the deviation of the code A₀ accounting for permissible changes in the reflected signal.

2. System for remotely detecting metal items, for example, weapons, containing:

a unit for scanning the controlled space, in which potentially threatening metal items may be located, with electromagnetic radiation;

a receiver of the reflected signal connected to this unit;

a processor connected to this receiver;

a display and video camera connected to the processor;

wherein the scanning unit is designed as a phased antenna array radiating a continuous frequency-modulated super high or ultra high frequency signal and the control inputs of the array are connected to the processor outputs;

wherein the processor records to its memory the codes of the amplitudes of the output signals of the receiver of the reflected signal for all radiation directions at the initial scanning period when the no potentially threatening metal items are allowed in the scanning sector and records detection of potentially threatening metal items during subsequent scanning periods if for some radiation direction one of the two comparison conditions holds;

A_i>

A₀+Δ

or A_i<

A₀−

Δ

,

where

A_i is the code of the amplitude of the signal at the output of the receiver of the reflected signal during any scanning period after the initial one for any of the radiation directions;

A₀ is the code of the amplitude of the signal at the output of the receiver of the reflected signal during the initial scanning period for the same radiation direction for which the code A_i was obtained;

Δ

>

0 is the tolerance of the deviation of the code A₀ accounting for permissible changes in the reflected signal.