METHOD AND DEVICE FOR IMAGING TEST OBJECTS BY MEANS OF ELECTROMAGNETIC WAVES, IN PARTICULAR FOR INSPECTING INDIVIDUALS FOR SUSPICIOUS ITEMS

• US 20080211713A1
• Filed: 03/07/2008
• Published: 09/04/2008
• Est. Priority Date: 09/07/2005
• Status: Active Grant

• Current Assignee: Friedrich-Alexander-Universitat Erlangen-Nurnberg, Smiths Heimann GmbH
• Original Assignee: Friedrich-Alexander-Universitat Erlangen-Nurnberg, Smiths Heimann GmbH
• Inventors: JECK, Michael
• Granted Patent: US 7,609,196 B2
• Time in Patent Office: Days
• US Class Current: 342/25A
• CPC Class Codes: G01S 13/02 Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
• CPC Class Codes: G01S 13/887 for detection of concealed objects, e.g. contraband or weapons
• CPC Class Codes: G01S 13/90 using synthetic aperture techniques , e.g. synthetic aperture radar [SAR] techniques
• CPC Class Codes: G01S 13/9082 Rotating SAR [ROSAR]
• CPC Class Codes: G01S 13/9088 Circular SAR [CSAR, C-SAR]
• CPC Class Codes: H01Q 3/08 for varying two co-ordinates of the orientation

Abstract

A method for imaging test objects by means of electromagnetic waves, in particular for the purpose of checking individuals for suspicious articles, in which method the test object is illuminated by electromagnetic waves, the scattered waves are received and evaluated for an imaginal representation of the test object on the basis of the synthetic aperture principle (SAR). A synthetic aperture is produced by the waves output by an antenna being concentrated initially in spatial terms, the point of high concentration being moved on a reflector along a circle.

Claims

1. A method for imaging test objects or inspecting individuals for suspicious items by electromagnetic waves,

illuminating the test object or individual with electromagnetic waves;

receiving and analyzing scattered waves using a synthetic aperture principle to display an image of the test object; and

providing a synthetic aperture by first spatially concentrating the scattered waves emitted by an antenna,

wherein a location of high concentration is manipulated such that it serves as a moving virtual antenna for the SAR analysis.

2. The method according to claim 1, wherein millimeter waves having a frequency between 1 GHz and 10 THz or between 30 GHz and 300 GHz, are used.

3. The method according to claim 1, wherein parallel diverging cones of rays are sequentially produced by a quasi-optical element through rotation of the antenna.

4. The method according to claim 1, wherein parallel diverging cones of rays with a changing angle of inclination are sequentially produced by a quasi-optical element through rotation of the antenna so that the cones of rays remain aimed at a substantially same point in space in the manner of a spotlight SAR.

5. A device for imaging test objects or inspecting individuals for suspicious items by electromagnetic waves, the device comprising:

an antenna for emitting the electromagnetic waves;

an apparatus for spatially concentrating the emitted waves, and

an apparatus for manipulation of the waves at a location of high concentration in such a manner that this location serves as a moving virtual antenna for an SAR analysis.

6. The device according to claim 5, wherein the antenna emits and receives electromagnetic waves and/or millimeter waves, and wherein the apparatus for spatially concentrating the emitted also spatially concentrates the received electromagnetic waves.

7. The device according to claim 5, further comprising a rotating component from which the waves are reflected and concentrated onto a reflector, wherein the reflector emits a moving, diverging cone of rays.

8. The device according to claim 5, wherein a rotatable antenna and a subsequent focusing element, from which the waves are concentrated onto a quasi-optical element, and wherein the quasi-optical element emits a diverging cone of rays that are displaced in parallel during a rotational motion of the antenna.

9. The device according to claim 5, wherein a virtual source is produced by a Nipkow disk, which covers a strip upon which the waves emitted by an antenna are focused.

10. The device according to claim 5, wherein the antenna is connected to a transmitting and receiving device through a suitable component, in particular through couplers, circulators, and/or an arrangement of reflector grids.

11. The device according to claim 5, wherein the antenna is composed of at least one transmitting antenna and at least one spatially separated receiving antenna.