System and method for near-field electromagnetic ranging

• US 6,963,301 B2
• Filed: 01/31/2003
• Issued: 11/08/2005
• Est. Priority Date: 08/19/2002
• Status: Expired due to Term

• Current Assignee: GaN Corporation
• Original Assignee: G-Track Corporation
• Inventors: Schantz, Hans Gregory, DePierre, Robert Edward
• Primary Examiner(s): Lobo, Ian J.
• Application Number:
  US10/355,612
• Publication Number:
  US 20040032363A1
• Time in Patent Office: 1,012 Days
• Field of Search: 342/118, 342/125, 342/127, 342/145, 342/424, 342/442, 342/458, 367/128
• US Class Current: 342/125
• CPC Class Codes: G01S 11/06 using intensity measurements
• CPC Class Codes: G01S 13/75 using transponders powered from received waves, e.g. using passive transponders , or using passive reflectors
• CPC Class Codes: G01S 5/0027 of actual mobile position, i.e. position determined on mobile
• CPC Class Codes: G01S 5/0081 Transmission between base stations
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: H04B 5/24 Inductive coupling

Abstract

A system for measuring distance between a first locus and a second locus includes: (a) at least one beacon device; a respective beacon device of the at least one beacon device being situated at the first locus and transmitting a respective electromagnetic signal; and (b) at least one locator device; a respective locator device of the at least one locator device being situated at the second locus and receiving the respective electromagnetic signal. The respective locator device is situated at a distance from the respective beacon device within near-field range of the respective electromagnetic signal. The respective locator device distinguishes at least two characteristics of the respective electromagnetic signal. The respective locator device employs the at least two characteristics to effect the measuring.

Claims

1. A system for measuring distance between a first locus and a second locus;

the system comprising;

(a) a beacon device situated at said first locus and transmitting an electromagnetic signal; and

(b) a locator device situated at said second locus and receiving said electromagnetic signal;

said locator device being situated at a distance from said beacon device within near-field range of said electromagnetic signal;

said locator device distinguishing at least two characteristics of said electromagnetic signal sensed at said second locus;

said locator device employing said at least two characteristics to effect said measuring.

4. A system for measuring distance between a first locus and a second locus as recited in claim 1 wherein said beacon device and said locator device are coupled in a unitary assembly.

7. A system for measuring distance between a first locus and a second locus as recited in claim 1 wherein the system further comprises a least one additional locator device to include at least n locator devices in the system effecting said measuring to said beacon device for ascertaining location of said beacon device in n dimensions.

2. A system for measuring distance between a first locus and a second locus;

the system comprising;

(a) a beacon device situated at said first locus and transmitting an electromagnetic signal; and

(b) a locator device situated at said second locus and receiving said electromagnetic signal;

said locator device being situated at a distance from said beacon device within near-field range of said electromagnetic signal;

said locator device distinguishing at least two characteristics of said electromagnetic signal at said second locus;

said locator device employing said at least two characteristics to effect said measuring;

said at least two characteristics being a first signal characteristic proportional to a magnetic field component of said electromagnetic signal, and a second signal characteristic proportional to an electric field component of said electromagnetic signal.

3. A system for measuring distance between a first locus and a second locus as recited in claim 2 wherein said respective locator device effects said measuring by measuring a phase difference between said magnetic field component and said electric field component of said electromagnetic signal and employing said phase difference to determine said distance.

5. A system for measuring distance between a first locus and a second locus as recited in claim 2 wherein said beacon device and said locator device are coupled in a unitary assembly.

6. A system for measuring distance between a first locus and a second locus;

the system comprising;

(a) a beacon device situated at said first locus and transmitting an electromagnetic signal; and

(b) a locator device situated at said second locus and receiving said electromagnetic signal;

said locator device being situated at a distance from said beacon device within near-field range of said electromagnetic signal;

said locator device distinguishing at least two characteristics of said electromagnetic signal at said second locus;

said locator device employing said at least two characteristics to effect said measuring;

said beacon device transmitting said electromagnetic signal in response to receiving an interrogating signal from said locator device.

9. A system for measuring distance between a first locus and a second locus as recited in claim 6 wherein said at least two characteristic are a first signal characteristic proportional to a magnetic field component of said electromagnetic signal, and a second signal characteristic proportional to an electric field component of said electromagnetic signal, and wherein said locator device effects said measuring by measuring a phase difference between said magnetic field component and said electric field component and employing said phase difference to determine said distance.

8. A system for measuring distance between a first locus and a second locus;

the system comprising;

(a) a beacon device situated at said first locus and transmitting a electromagnetic signal; and

(b) a locator device situated at said second locus and receiving said electromagnetic signal;

said locator device being situated at a distance from said beacon device within near-field range of said electromagnetic signal;

said locator device distinguishing at least two characteristics of said electromagnetic signal at said second locus;

said locator device employing said at least two characteristics to effect said measuring;

said beacon device and said locator device being coupled in a unitary assembly;

said least two characteristics being a first signal characteristic proportional to a magnetic field component of said electromagnetic signal, and a second signal characteristic proportional to an electric field component of said electromagnetic signal;

said locator device effecting said measuring by measuring a phase difference between said magnetic field component and said electric field component and employing said phase difference to determine said distance.

10. A system for measuring distance between a first locus and a second locus;

the system comprising;

(a) a beacon device situated at said first locus and transmitting an electromagnetic signal;

(b) a locator device situated at said second locus and receiving said electromagnetic signal;

said locator device being situated at a distance from said beacon device within near-field range of said electromagnetic signal;

said locator device distinguishing at least two characteristics of said electromagnetic signal at said second locus;

said locator device employing said at least two characteristics to effect said measuring; and

(c) at least one additional locator device to include at least n locator devices in the system effecting said measuring to said beacon device for ascertaining location of said beacon device in n dimensions;

said at least two characteristics being a first signal characteristic proportional to a magnetic field component of said electromagnetic signal, and a second signal characteristic proportional to an electric field component of said electromagnetic signal;

each respective locator device of said at least n locator devices effecting said measuring by measuring a phase difference between said magnetic field component and said electric field component and employing said phase difference to determine said distance.

11. An apparatus for effecting electromagnetic ranging;

the apparatus comprising;

(a) a transmitter device for transmitting an electromagnetic wave;

(b) a receiver device for receiving said electromagnetic wave;

said receiver device being situated a distance from said transmitter device within near-field range of said electromagnetic wave;

said receiver device comprising a first receiver means for detecting a first characteristic of said electromagnetic wave and a second receiver means substantially collocated with said first receiver means for detecting a second characteristic of said electromagnetic wave;

(c) a measuring device coupled with said receiver device for measuring a difference at said receiver device between said first characteristic and said second characteristic; and

(d) a determining device coupled with said measuring device for employing said difference to calculate said distance.

12. An apparatus for effecting electromagnetic ranging comprising:

(a) a transmitter device for transmitting an electromagnetic wave;

(b) a receiver device for receiving said electromagnetic wave;

said receiver device being situated a distance from said transmitter device with near-field range of said electromagnetic wave;

said receiver device comprising a first receiver means for detecting a first characteristic of said electromagnetic wave and a second receiver means substantially collocated with said first receiver means for detecting a second characteristic of said electromagnetic wave;

(c) a measuring device coupled with said receiver device for measuring a difference between said first characteristic and said second characteristic; and

(d) a determining device coupled with said measuring device for employing said difference to calculate said distance;

said first characteristic being a first signal characteristic proportional to a magnetic field component of said electromagnetic wave, and said second characteristic being a second signal characteristic proportional to an electric field component of said electromagnetic wave;

said difference being a phase difference between said magnetic field component and said electric field component;

said determining device employing said phase difference to calculate said distance.

13. An apparatus for effecting electromagnetic ranging;

the apparatus comprising;

(a) a transmitter device for transmitting an electromagnetic wave;

(b) a receiver device for receiving said electromagnetic wave;

said receiver device being situated a distance from said transmitter device within near-field range of said electromagnetic wave;

said receiver device comprising a first receiver means for detecting a first characteristic of said electromagnetic wave and a second receiver means substantially collocated with said first receiver means for detecting a second characteristic of said electromagnetic wave;

(c) a measuring device coupled with said receiver device for measuring a difference between said first characteristic and said second characteristic; and

(d) a determining device coupled with said measuring device for employing said difference to calculate said distance;

said transmitter device transmitting said electromagnetic wave in response to receiving an interrogating signal from said receiver device.

14. An apparatus for effecting electromagnetic ranging as recited in claim 13 wherein said first characteristic is a first signal characteristic proportional to a magnetic field component of said electromagnetic wave, and said second characteristic is a second signal characteristic proportional to an electric field component of said electromagnetic wave, and wherein said difference is a phase difference between said magnetic field component and said electric field component;

said determining device employing said phase difference to calculate said distance.

15. A method for measuring distance between a first locus and a second locus;

the method comprising the steps of;

(a) transmitting an electromagnetic signal from said first locus;

(b) receiving said electromagnetic wave at said second locus;

said second locus being within near-field range of said electromagnetic signal;

(c) in no particular order;

(1) detecting a first characteristic of said electromagnetic signal at said second lotus; and

(2) detecting a second characteristic of said electromagnetic signal at said second lotus;

(d) measuring a difference at said second locus between said first characteristic and said second characteristic; and

(e) employing said difference to calculate said distance.

16. A method for measuring distance between a first locus and a second locus;

the method comprising the steps of;

(a) transmitting an electromagnetic signal from said first locus;

(b) receiving said electromagnetic wave at said second locus;

said second locus being within near-field range of said electromagnetic signal;

(c) in no particular order;

(1) detecting a first characteristic of said electromagnetic signal at said second locus; and

(2) detecting a second characteristic of said electromagnetic signal at said second locus;

(d) measuring a difference between said first characteristic and said second characteristic; and

(e) employing said difference to calculate said distance;

said first characteristic being a first signal characteristic proportional to a magnetic field component of said electromagnetic signal;

said second characteristic being a second signal characteristic proportional to an electric field component of said electromagnetic signal;

said difference being a phase difference between said magnetic field component and said electric field component.

17. A method for measuring distance between a first locus and a second locus;

the method comprising the steps of;

(a) transmitting an electromagnetic signal from said first locus;

(b) receiving said electromagnetic wave at said second locus;

said second locus being within near-field range of said electromagnetic signal;

(c) in no particular order;

(1) detecting a first characteristic of said electromagnetic signal at said second locus; and

(2) detecting a second characteristic of said electromagnet signal at said second locus;

(d) measuring a difference between said first characteristic and said second characteristic; and

(e) employing said difference to calculate said distance;

said transmitting said electromagnetic signal occurring in response to receiving an interrogating signal.

18. A method for measuring distance between a first locus and a second locus as recited in claim 17 wherein said first characteristic is a first signal characteristic proportional to a magnetic field component of said electromagnetic signal, and said second characteristic is a second signal characteristic proportional to an electric field component of said electromagnetic signal, and wherein said difference is a phase difference between said magnetic field component and said electric field component.