Handheld radar frequency scanner for concealed object detection

• US 7,518,542 B1
• Filed: 09/27/2005
• Issued: 04/14/2009
• Est. Priority Date: 12/03/2001
• Status: Expired due to Term

• Current Assignee: L3harris Fuzing and Ordnance Systems Incorporated
• Original Assignee: CyTerra Corp. (L3Harris Technologies, Inc.)
• Inventors: Duvoisin, Herbert III, Fine, David H., Konduri, Ravi K., Steinway, William, Stilwell, Gregory
• Primary Examiner(s): ALSOMIRI, ISAM A
• Application Number:
  US11/235,533
• Time in Patent Office: 1,295 Days
• Field of Search: 342 21- 22, 342 27- 28, 342/90, 342/173, 342/199
• US Class Current: 342/22
• CPC Class Codes: G01S 13/0209 Systems with very large relative bandwidth, i.e. larger than 10 %, e.g. baseband, pulse, carrier-free, ultrawideband
• CPC Class Codes: G01S 13/04 Systems determining presence of a target based on relative movement of target G01S13/56
• CPC Class Codes: G01S 13/24 using frequency agility of carrier wave
• CPC Class Codes: G01S 7/412 based on a comparison between measured values and known or stored values
• CPC Class Codes: H01Q 1/22 by structural association with other equipment or articles
• CPC Class Codes: H01Q 1/242 specially adapted for hand-held use
• CPC Class Codes: H01Q 9/27 Spiral antennas

Abstract

A handheld radar frequency scanner system for detecting objects concealed on a person, the system includes a radar transmitter coupled to a transmit antenna that is configured and positioned to direct a radar signal at a person, a radar receiver coupled to a receive antenna that is configured to detect a portion of the radar signal reflected by the person, and a processor connected to the radar receiver and operable to process the portions of the radar signals detected by the radar receiver to determine whether the person is carrying a concealed object. The system may produce a real-time alert, such as an audible alert, when a concealed object is detected.

Claims

1. A handheld radar frequency scanner system for detecting objects concealed on a person, the system comprising:

a radar transmitter coupled to a transmit antenna that is configured and positioned to direct a radar signal at a person;

a radar receiver coupled to a receive antenna that is configured to detect a portion of the radar signal reflected by the person;

a signal processor assembly including a processor, the signal processing assembly being connected to the radar receiver and operable to process the portion of the radar signal detected by the radar receiver to determine whether the person is carrying a concealed object on a body of the person by conducting a test in which a first characteristic of a first dielectric constant associated with the person is determined, and a second characteristic of a second dielectric constant associated with the concealed object is determined; and

a display coupled to the signal processor assembly that is operable to produce an alert when a concealed object is detected.

2. The system of claim 1 wherein the display is configured to produce a real-time alert when a concealed object is detected.

3. The system of claim 2 wherein the display is configured to produce an audible alert.

4. The system of claim 2 wherein the display is configured to produce a visual alert.

5. The system of claim 2 wherein the display is configured to produce both a visual alert and an audible alert.

6. The system of claim 1 wherein the radar signal comprises a frequency between approximately 1.5 gigahertz and 12 gigahertz.

7. The system of claim 6 wherein the radar signal comprises an output power of less than one milliwatt.

8. The system of claim 6 wherein the radar signal comprises a frequency stepped signal.

9. The system of claim 8 wherein the processor is operable to conduct the test using a frequency-stepped scheme.

10. The system of claim 8 wherein the frequency stepped signal comprises frequencies at defined intervals throughout a defined frequency range.

11. The system of claim 1 wherein the handheld radar frequency scanner system comprises a monostatic radar system.

12. The system of claim 1 wherein the handheld radar frequency scanner system comprises a bistatic radar system.

13. The system of claim 1 wherein the first dielectric constant is determined during the test.

14. The system of claim 13 wherein the first dielectric constant is associated with skin of the person.

15. The system of claim 13 wherein the second dielectric constant is determined during the test.

16. The system of claim 1 wherein the processor is operable to conduct the test based upon a difference between the first dielectric constant and the second dielectric constant, wherein the difference is determined during the test.

17. The system of claim 1 wherein the processor is operable to determine whether the person is carrying a concealed object using a principal component analysis technique.

18. A method for detecting objects concealed on a person using a handheld radar frequency scanner system, the method comprising:

directing a radar signal at a person;

detecting a portion of the radar signal reflected by the person;

processing the portion of the radar signal detected by the radar receiver determine whether the person is carrying a concealed object on a body of the person by conducting a test in which a first characteristic of a first dielectric constant associated with the person is determined, and a second characteristic of a second dielectric constant associated with the concealed object is determined; and

producing a visual alert when a concealed object is detected.

19. The method of claim 18 further comprising wherein producing a visual alert comprises producing a real-time alert when a concealed object is detected.