Computerized tomography using radar

• US 7,312,742 B2
• Filed: 05/30/2006
• Issued: 12/25/2007
• Est. Priority Date: 05/31/2005
• Status: Expired due to Fees

• Current Assignee: L-3 Communications Security & Detection Systems, Inc. (Leidos Holdings, Inc.)
• Original Assignee: L-3 Communications Security & Detection Systems, Inc. (Leidos Holdings, Inc.)
• Inventors: Steinway, William, Fine, David H., Cole, Steve
• Primary Examiner(s): Gregory, Bernarr E.
• Application Number:
  US11/421,013
• Publication Number:
  US 20070035437A1
• Time in Patent Office: 574 Days
• Field of Search: 342/21, 342/22, 342 25 R- 25 F, 342/59, 342/118, 342128-133, 342/175, 342/176, 342/179, 342/195, 342/89
• 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 13/878 Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector G01S13/874 takes precedence
• CPC Class Codes: G01S 13/89 for mapping or imaging

Abstract

Sensing characteristics of an object includes transmitting a stepped-frequency radar through an object and detecting, with multiple receiving structures, deflected portions of the radar signal. The detected portions are processed to generate processed data including information associated with amplitudes and phases of the deflected portions, and with the locations of the receiving structures at which the deflected portions were detected. The processed data is analyzed to determine information corresponding to dielectric properties particular positions within the object.

Claims

1. A method of sensing characteristics of an object, the method comprising:

transmitting a stepped-frequency radar signal through an object;

detecting, with multiple receiving structures, deflected portions of the radar signal;

processing the detected portions to generate processed data including information associated with amplitudes and phases of the deflected portions, and with the locations of the receiving structures at which the deflected portions were detected; and

analyzing the processed data to determine information corresponding to dielectric properties, the dielectric properties corresponding to particular positions within the object.

2. The method of claim 1, wherein detecting deflected portions of the radar signal includes sequentially detecting with multiple receiving structures such that only a single receiving structure actively detects at a time.

3. The method of claim 2, wherein detecting deflected portions of the radar signal includes detecting sequentially different groups of receiving structures, wherein receiving structures within a particular group detect concurrently.

4. The method of claim 1, wherein detecting deflected portions of the radar signal includes detecting with multiple receiving structures concurrently.

5. The method of claim 1, wherein multiple transmitting structures transmits a frequency within the stepped-frequency radar signal, wherein at least two of the transmitting structure transmits a different frequency.

6. The method of claim 5, wherein detecting deflected portions of the radar signal includes detecting with multiple receiving structures concurrently.

7. The method of claim 1, wherein detecting deflected portions of the radar signal includes detecting with receiving structures that surround the object.

8. The method of claim 1, wherein detecting deflected portions of the radar signal includes detecting with receiving structures that form a shape that is not round.

9. The method of claim 1, wherein detecting deflected portions of the radar signal includes detecting with receiving structures that form a shape that is three dimensional.

10. The method of claim 1, wherein an image is formed using the analyzed data, wherein the image displays areas inside the object and corresponding information associated with dielectric levels.

11. The method of claim 10, wherein multiple transmission or detections of multiple locations of the object are used to form the image in three dimensions.

12. The method of claim 1, wherein results of a first scan using computerized tomography of x-rays automatically triggers the transmission of a stepped-frequency radar signal only if the results of the first scan suggest the transmission.

13. The method of claim 12, wherein the automatically triggered transmission is targeted automatically to a specific physical location of the object for which the results of the first scan suggest transmission.

14. The method of claim 1, wherein the processing or analyzing includes adjusting information associated with the phase or amplitude based upon the receiving structure, wherein processing or analyzing associated with different receiving structures is adjusted differently.

15. The method of claim 1, wherein the processing or analyzing includes adjusting information associated with the phase or amplitude based upon the physical characteristics of the object to scan, wherein processing or analyzing associated with different physical characteristics is adjusted differently.

16. The method of claim 15, wherein the physical characteristics include dielectric properties of one or more layers in the object, and the dielectric properties are measured or estimated based on the detected deflecting portions.

17. The method of claim 1, wherein the object is moved or vibrated during the transmission of the stepped-frequency radar signal and the detecting of the deflected portions.

18. The method of claim 17, wherein a Doppler shift in the deflected portions is used to distinguish detected portions of the signal that have been deflected from the object from other detected signals.

19. The method of claim 18, wherein the Doppler shift is associated with movement of the object by a conveyer belt.

20. The method of claim 17, wherein the Doppler shift is associated with vibrations of the object by a vibrating platform.

21. A device for sensing characteristics, the device comprising:

one or more transmission structures configured to transmit a stepped-frequency radar signal including a plurality of frequencies through an object;

a plurality of receiving structures configured to detect deflected portions of the radar signal;

a processor configured to process the detected portions to generate processed data including information associated with amplitude, phase, and the receiving structure in which the reflected portion was detected; and

an analyzer configured to analyze the processed data to determine information corresponding to dielectric properties of the object at an associated position, within the object, of the information corresponding to dielectric properties.

22. A device for sensing characteristics, the device comprising:

means for transmitting a stepped-frequency radar signal including a plurality of frequencies through an object;

means for detecting, with a plurality of receiving structures, deflected portions of the radar signal;

means for processing the detected portions to generate processed data including information associated with amplitude, phase, and the receiving structure in which the reflected portion was detected; and

means for analyzing the processed data to determine information corresponding to dielectric properties of the object at an associated position, within the object, of the information corresponding to dielectric properties.