Device for detecting objects borne by an individual

• US 10,641,889 B2
• Filed: 02/21/2017
• Issued: 05/05/2020
• Est. Priority Date: 02/24/2016
• Status: Active Grant

• Current Assignee: SAS SWS, SWS Incorporated
• Original Assignee: SWS Incorporated
• Inventors: Chekroun, Claude, Chekroun, Gilles
• Primary Examiner(s): Barker, Matthew M
• Application Number:
  US15/438,568
• Publication Number:
  US 20170242119A1
• Time in Patent Office: 1,169 Days
• CPC Class Codes: G01S 13/003 Bistatic radar systems; Multistatic radar systems
• CPC Class Codes: G01S 13/867 Combination of radar systems with cameras
• CPC Class Codes: G01S 13/887 for detection of concealed objects, e.g. contraband or weapons
• CPC Class Codes: G01S 13/904 SAR modes
• CPC Class Codes: G01S 7/03 Details of HF subsystems specially adapted therefor, e.g. common to transmitter and receiver
• CPC Class Codes: H01Q 1/42 Housings not intimately mechanically associated with radiating elements, e.g. radome

Abstract

A device comprises at least: one rotary antenna including at least two parallel rectilinear waveguides; a radar emitting a continuous-wave microwave signal towards the emission guide of the antenna and receiving the signals from the guides of the antenna, which signals are captured by the movable beam, the received signals are the direct component I and the quadrature component; a stereoscopic video camera oriented in the same direction as the movable beam of the rotary antenna and able to record the clothing envelope of the individual, the envelope serving as a reference surface for the measurement of distances to the device; a processor that computes an SAR image of that portion of the body of the individual targeted by the radar and the video camera and who is possibly equipped with one or more objects, from signals received from the radar and the distances measured by the video camera.

Claims

1. A device for detecting objects borne by immobile or moving individuals, comprising:

first and second rotary antennas, each including at least two parallel rectilinear waveguides, one of the two waveguides being an emission guide that is configured to transmit an emission wave and the other of the two being a reception guide that is configured to transmit a reception wave, and a movable cylinder provided with a helicoidal slot rotatably movable about said waveguides, the waveguides being open facing an interior face of said movable cylinder, said interior face forming a microwave short-circuit in order to close said waveguides, a movable radiating source being located facing said waveguides subsequent to the rotational movement of said moveable cylinder inducing a movable emission and reception beam able to be oriented in a direction towards an individual;

one radar configured to emit the emission wave, which is a continuous wave microwave signal, towards the emission guide of said first antenna and to receive signals captured by said movable beam from the waveguides of said second antenna, said received signals including a direct component I and a quadrature component;

one stereoscopic video camera that is configured to be oriented in the direction towards the individual and able to record a clothing envelope of said individual, said clothing envelope being a reference surface defined by measurements of distances between an item of clothing of said individual and said device; and

one processor configured to compute a synthetic aperture radar image of a portion of the body of said individual which is targeted by said radar and said video camera and who is possibly equipped with one or more objects, from signals received from said radar and from the clothing envelope recorded by said video camera,

wherein said radar is configured to operate in a bi-static mode, said first rotary antenna realizing emission and said second rotary antenna being dedicated to reception.

2. The device according to claim 1, wherein the two waveguides are etched into an interior cylinder that is disposed in an interior of the movable cylinder, the two cylinders having a same axis, a space between the two cylinders is equal to 0.1 mm±

0.05 mm.

3. The device according to claim 1, wherein said rotary antennas include a system for minimizing microwave leaks, said system being composed of three cavities, said cavities being arranged pairwise on each side of said waveguides, parallel thereto, over all their length.

4. The device according to claim 1, wherein said waveguides are etched into an interior cylinder that is disposed in an interior of the movable cylinder, said movable cylinder is rotatably movable by way of a ball bearing device, a base of said movable cylinder and a base of said interior cylinder being mechanically secured to a movable portion and a stationary portion of said ball bearing device, respectively.

5. The device according to claim 1, wherein said radar is configured to operate in a millimetre-wave frequency band.

6. The device according to claim 1, wherein the antennae are connected together by two additional waveguides including a first waveguide that connects the emission guides of said antennae and a second waveguide that connects the reception guides, the first waveguide being connected via a magic T to the radar and the second waveguide being connected via another magic T to the radar.

7. The device according to claim 1, wherein

said radar emits at a number N of frequencies, and

said processor being configured to perform objects classification by:

performing a first level of analysis of the image for signals received at a first of said frequencies; and

performing other analyses for signals received at other frequencies of said frequencies.

8. The device according to claim 1, wherein the processor is an integral part of said radar.

9. The device according to claim 1, comprising a viewer for viewing the obtained images, said viewer being glasses worn by a user and onto which said images are projected.

10. The device according to claim 1, wherein the first and second antennas and the radar are provided in an interior of a portable cylindrical radome, and said radome supports said video camera.