Radar detection of a concealed object on a body

• US 9,903,948 B2
• Filed: 10/10/2013
• Issued: 02/27/2018
• Est. Priority Date: 10/10/2012
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Kim, Jacob, Skalenda, William F., Tomich, John L., Samaniego, Raymond
• Primary Examiner(s): Barker, Matthew M
• Application Number:
  US14/051,037
• Publication Number:
  US 20160223666A1
• Time in Patent Office: 1,601 Days
• Field of Search: 342 22, 342 27, 342188
• 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 material in a target comprising a body and the concealed material, the method comprising: emitting radio frequency (RF) energy toward a direction of the target, capturing a signal corresponding to a scattered RF energy reflected from the target, measuring a first mean signal level in a first frequency band of the signal, measuring a second mean signal level in a second frequency band of the signal, and detecting the concealed material when the difference between the first mean signal level and the second mean signal level is above a threshold.

Claims

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

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

capturing, by a receiver, a signal corresponding to a scattered RF energy reflected from the target, the captured RF energy being in a first frequency band and a second frequency band;

measuring, by a processor, a first mean signal level in the first frequency band of the signal and a second mean signal level in the second frequency band of the signal, the first frequency band being a frequency range in which the concealed material has a resonant RF scattering response, and the second frequency band being a frequency range in which the concealed material lacks a resonant RF scattering response; and

detecting, by the processor, the concealed material when the difference between the first mean signal level and the second mean signal level is above a threshold.

2. The method of claim 1, wherein the emitting RF energy further comprises:

emitting RF energy of one or more of a horizontal polarity and a vertical polarity.

3. The method of claim 1, wherein the captured scattered RF energy reflected from the target has a horizontal polarization.

4. The method of claim 1, wherein the captured scattered RF energy reflected from the target has a vertical polarization.

5. The method of claim 1, wherein the first frequency band is a frequency range in which the body lacks a resonant RF scattering response.

6. The method of claim 1, wherein the body is a human body and the second frequency band is a frequency range in which the human body lacks a resonant RF scattering response.

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

8. The method of claim 1, further comprising:

retrieving the threshold and the frequency ranges of the first and second frequency bands from a stored data record.

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

an emitter configured to emit radio frequency (RF) energy toward a direction of the target;

a receiver configured to capture a signal corresponding to a scattered RF energy reflected from the target, the captured RF energy being in a first frequency band and a second frequency band; and

a processor configured to measure a first mean signal level in the first frequency band of the signal, to measure a second mean signal level in the second frequency band of the signal, and to detect the concealed material when the difference between the first mean signal level and the second mean signal level is at or above a threshold,

wherein the first frequency band is a frequency range in which the concealed material has a resonant RF scattering response

wherein the second frequency band is a frequency range in which the concealed material lacks a resonant RF scattering response.

10. The radar detector of claim 9, wherein the emitter emits RF energy of a horizontal polarity or vertical polarity.

11. The radar detector of claim 9, wherein the captured scattered RF energy reflected from the target has a horizontal polarization.

12. The radar detector of claim 9, wherein the captured scattered RF energy reflected from the target has a vertical polarization.

13. The radar detector of claim 9, wherein the first frequency band is a frequency range in which the body lacks a resonant RF scattering response.

14. The radar detector of claim 9, wherein the body is a human body and the second frequency band is a frequency range in which the human body lacks a resonant RF scattering response.

15. The radar detector of claim 9, wherein the body is a human body and the concealed material comprises explosive material or shrapnel.