DETECTION OF CONCEALED OBJECT ON A BODY USING RADIO FREQUENCY SIGNATURES ON FREQUENCIES AND POLARIZATIONS

• US 20150276920A1
• Filed: 10/09/2013
• Published: 10/01/2015
• Est. Priority Date: 10/10/2012
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Kim, Jacob, Tomich, John L., Samaniego, Raymond, Choe, Howard C.
• Granted Patent: US 9,857,462 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01S 13/887 for detection of concealed objects, e.g. contraband or weapons
• CPC Class Codes: G01S 7/025 involving the transmission of linearly polarised waves
• CPC Class Codes: G01S 7/354 Extracting wanted echo-signals Doppler systems G01S13/50
• CPC Class Codes: G01S 7/411 Identification of targets based on measurements of radar reflectivity G01S7/415 takes precedence
• CPC Class Codes: G01S 7/412 based on a comparison between measured values and known or stored values

Abstract

A method for detecting a concealed object in a target comprising a body and the concealed object, the method including emitting, by an emitter, radio frequency (RF) energy toward a direction of the target, receiving, by a receiver, a scattered RF energy reflected from the target, generating, by the receiver, a signal corresponding to the received scattered RF energy, comparing, by a processor, the signal with a plurality of stored RF scattering signatures, each of the RF scattering signatures being associated with an object of interest, and detecting, by the processor, the concealed object when the signal matches one of plurality of RF scattering signatures.

Claims

1. A method for detecting a concealed object in a target comprising a body and the concealed object, the method comprising:

emitting, by an emitter, radio frequency (RF) energy toward a direction of the target;

receiving, by a receiver, a scattered RF energy reflected from the target;

generating, by the receiver, a signal corresponding to the received scattered RF energy;

comparing, by a processor, the signal with a plurality of stored RF scattering signatures, each of the RF scattering signatures being associated with an object of interest; and

detecting, by the processor, the concealed object when the signal matches one of plurality of stored RF scattering signatures.

2. The method of claim 1, further comprising:

retrieving the plurality of stored RF scattering signatures from a stored data record.

3. The method of claim 1, further comprising:

identifying the concealed object based on the matching one of the plurality of RF scattering signatures.

4. The method of claim 1, wherein the emitting RF energy further comprises emitting RF energy of one or more of a horizontal polarization and a vertical polarization, and wherein the received scattered RF energy reflected from the target has a horizontal polarization or a vertical polarization.

5. The method of claim 1, wherein each of the plurality of stored RF scattering signatures is further associated with a transmit-receive polarization combination and a frequency band.

6. The method of claim 5, wherein the transmit-receive polarization combination comprises:

a horizontal polarization for the emitted RF energy, and a horizontal polarization for the received scattered RF energy;

a horizontal polarization for the emitted RF energy, and a vertical polarization for the received scattered RF energy;

a vertical polarization for the emitted RF energy, and a horizontal polarization for the received scattered RF energy;

or

a vertical polarization for the emitted RF energy, and a vertical polarization for the received scattered RF energy.

7. The method of claim 5, wherein the frequency band is a frequency range in which a RF scattering response of an associated object of interest is distinguishable from RF scattering responses of other objects of non-interest comprising clutter and the body.

8. The method of claim 1, wherein one or more of the stored RF scattering signatures represent one or more simulation results, or data collected from one or more real-world experiments.

9. The method of claim 1, wherein the body is a biological life form and the concealed object is a concealed weapon.

10. The method of claim 1, wherein the signal matches one of plurality of the RF scattering signatures when a standard deviation of a difference between the signal and the one of the plurality of RF scattering signatures is below a threshold.

11. The method of claim 1, wherein the signal matches one of plurality of the RF scattering signatures when a mean of a difference between the signal and the one of the plurality of RF scattering signatures is below a threshold.

12. A method for detecting one or more concealed objects in a target comprising a body and the one or more concealed object, the method comprising:

emitting, by an emitter, radio frequency (RF) energy toward a direction of the target;

receiving, by a receiver, a scattered RF energy reflected from the target;

generating, by the receiver, one or more signals corresponding to the received scattered RF energy;

comparing, by a processor, each of the one or more signals with a plurality of stored RF scattering signatures, each of the RF scattering signatures being associated with an object of interest; and

detecting, by the processor, the one or more concealed objects when the one or more signals match one or more of the plurality of RF scattering signatures.

13. A radar detector configured to detect a concealed object in a target comprising a body and the concealed object, the radar detector comprising:

an emitter configured to emit RF energy toward a direction of the target;

a receiver configured to receive a scattered RF energy reflected from the target, and to generate a signal corresponding to the scattered RF energy reflected from the target; and

a processor configured;

to retrieve a plurality of stored RF scattering signatures from a stored data record;

to compare the signal with the plurality of stored RF scattering signatures, each of the stored RF scattering signatures being associated with an object of interest; and

to detect the concealed object when the signal matches one of plurality of stored RF scattering signatures.

14. The radar detector of claim 13, wherein the emitter emits RF energy of one or more of a horizontal polarization and vertical polarization.

15. The radar detector of claim 13, wherein the received scattered RF energy reflected from the target has a horizontal polarization or a vertical polarization.

16. The radar detector of claim 13, wherein each of the plurality of stored RF scattering signatures is further associated with a transmit-receive polarization combination and a frequency band.

17. The radar detector of claim 16, wherein the transmit-receive polarization combination comprises:

a horizontal polarization for the emitted RF energy, and a horizontal polarization for the received scattered RF energy;

a horizontal polarization for the emitted RF energy, and a vertical polarization for the received scattered RF energy;

a vertical polarization for the emitted RF energy, and a horizontal polarization for the received scattered RF energy;

or

a vertical polarization for the emitted RF energy, and a vertical polarization for the received scattered RF energy.

18. The radar detector of claim 16, wherein the frequency band is a frequency range in which a RF scattering response of an associated object of interest is distinguishable from RF scattering responses of other objects of non-interest comprising clutter and the body.

19. The radar detector of claim 13, wherein the body is a biological life form and the concealed object is a concealed weapon.

20. The radar detector of claim 13, wherein the signal matches one of plurality of stored RF scattering signatures when a standard deviation of a difference between the signal and the one of the plurality of stored RF scattering signatures is below a threshold.