Methods and systems for determining the phase constant for a dielectric medium

• US 8,044,838 B1
• Filed: 08/13/2008
• Issued: 10/25/2011
• Est. Priority Date: 08/13/2008
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Maynard, William David, Barr, Samuel Allan
• Primary Examiner(s): Tarcza; Thomas
• Assistant Examiner(s): BYTHROW, PETER M
• Application Number:
  US12/190,738
• Publication Number:
  US 20110267215A1
• Time in Patent Office: 1,168 Days
• Field of Search: 342/22, 342/165, 342/173, 342/174, 342/175, 342/192, 324/326, 324/452, 324/600, 324/658, 324/663, 324/674, 324/681
• US Class Current: 342/22
• CPC Class Codes: G01S 13/74 Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems
• CPC Class Codes: G01V 3/17 operating with electromagnetic waves operating with millimetre waves G01V8/005

Abstract

A method for determining a phase constant for a dielectric medium is provided. The method includes deploying a calibration object with a known free-space spectral response within a dielectric medium of interest, determining the spectral response of the calibration object deployed in the dielectric medium, and determining the phase constant for the dielectric medium using a relationship between the free-space spectral response of the calibration object and the spectral response of the calibration object when deployed in the dielectric medium.

Claims

1. A method for remotely determining the phase constant for a dielectric medium, said method comprising:

deploying a calibration object with a known free-space spectral response within a dielectric medium of interest;

determining the spectral response of the calibration object deployed in the dielectric medium; and

determining the phase constant for the dielectric medium using a relationship between the free-space spectral response of the calibration object and the spectral response of the calibration object when deployed in the dielectric medium.

2. The method of claim 1 further comprising providing a plurality of calibration objects.

3. The method of claim 2 wherein providing a plurality of calibration objects further comprises providing a plurality of calibration objects with the same known free-space spectral response.

4. The method of claim 2 wherein providing a plurality of calibration objects further comprises providing a plurality of calibration objects with at least one of the plurality of calibration objects having a different known free-space spectral response than another of said plurality of calibration objects.

5. The method of claim 1 further comprising deploying the calibration object from at least one of an air vehicle, a ground vehicle, a water vehicle, and a permanent station.

6. The method of claim 1 further comprising using the determined phase constant to detect other objects within the dielectric medium.

7. The method of claim 1 wherein providing a calibration object with a known free-space spectral response further comprises providing a calibration object that is capable of being deployed into the dielectric medium as a projectile.

8. The method of claim 1 further comprising:

transmitting a signal across a frequency range onto an area that includes the deployed calibration object within the dielectric medium; and

receiving reflected responses due to the transmission from the area that includes the deployed object.

9. The method of claim 8 wherein:

determining the spectral response of the calibration object deployed in the dielectric medium comprises determining the spectral response of the calibration object from the reflected responses; and

determining the phase constant for the dielectric medium comprises recording differences between a free-space spectral response of the calibration object and a spectral response of the calibration object when embedded in the dielectric medium.

10. The method of claim 8 wherein transmitting a signal across a frequency range onto an area comprises using a transmitter to perform a signal sweep to determine the resonant frequency of the calibration object embedded within the dielectric medium.

11. The method of claim 8 wherein using a detection device further comprises calibrating the detection device once the phase constant is known, in order to detect other objects located in the dielectric medium.

12. The method of claim 1 wherein determining the phase constant for the dielectric medium further comprises using a processor to determine the phase constant.

13. A system for determining a phase constant for a dielectric medium, said system comprising:

a calibration object having a known free-space spectral response and capable of being deployed within a dielectric medium for which the phase constant is to be determined

at least one transmitter;

at least one receiver, said at least one transmitter and said at least one receiver operable to determine a resonant frequency response of said calibration object when said calibration object is deployed within the dielectric medium; and

a processor operable to determine the phase constant for the dielectric medium utilizing the known free-space spectral response and the resonant frequency response of said calibration object within the dielectric medium.

14. The system of claim 13 further comprising a plurality of calibration objects.

15. The system of claim 14 wherein said plurality of calibration objects all have the same known free-space spectral response.

16. The system of claim 14 wherein at least one of said plurality of calibration objects has a different known free-space spectral response than another of said plurality of calibration objects.

17. The system of claim 13 wherein said processor is operable to calibrate said at least one transmitter and said at least one receiver to detect other objects in the dielectric medium once the phase constant for the dielectric medium is known.

18. The system of claim 13 wherein said calibration object is capable of being deployed from at least one of an air vehicle, a ground vehicle, a water vehicle, and a permanent station.

19. The system of claim 13 wherein said calibration object is capable of being deployed as a projectile.

20. The system of claim 13 wherein said processor is configured to be communicatively coupled to said at least one transmitter and said at least one receiver.

21. The system of claim 20 where at least one of said processor, said at least one transmitter, and said at least one receiver are mounted on one or more of an air vehicle, a ground vehicle, a water vehicle, and deployed at a permanent station.