Near field electromagnetic location system and method

• US 8,643,538 B2
• Filed: 12/23/2010
• Issued: 02/04/2014
• Est. Priority Date: 08/19/2002
• Status: Expired due to Fees

• Current Assignee: GaN Corporation
• Original Assignee: Q-Track Corporation
• Inventors: Schantz, Hans Gregory, DePierre, Robert Edward, Langford, David Wesley
• Primary Examiner(s): Lobo, Ian J
• Application Number:
  US12/977,067
• Publication Number:
  US 20110148714A1
• Time in Patent Office: 1,139 Days
• Field of Search: 342/118, 342/125, 342/127
• 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 and method for determining a position of a locus comprising a locator device for disposition at the locus; the locator device configured for receiving an electromagnetic signal from a beacon device, the locator device receiving at a distance from the beacon device within near field range of the electromagnetic signal; the locator device configured for distinguishing at least two characteristics of the electromagnetic signal sensed at the locus; the system employing the at least two characteristics to effect the determining of the position of the locus.

Claims

1. A system for determining a distance between a first locus and a second locus, the system comprising:

a beacon device comprising a transmitter and at least one transmitting antenna; and

a locator device comprising a receiver and at least one receiving antenna;

said beacon device for disposition at said first locus and said locator device for disposition at said second locus;

said beacon device configured for transmitting an electromagnetic signal and said locator device configured for receiving said electromagnetic signal from said beacon device;

said locator device configured for detecting at least two characteristics of said electromagnetic signal transmitted by said beacon device from said first locus and received by said locator device at said second locus when said second locus is within a near field distance from said first locus; and

said locator device further comprising a processor, said processor configured for employing said at least two characteristics to effect said determining of said distance in accordance with a predefined relationship between said at least two characteristics and said distance.

2. The system as recited in claim 1, wherein said at least two characteristics of said electromagnetic signal comprise a first characteristic related to an electric field component of said electromagnetic signal and a second characteristic related to a magnetic field component of said electromagnetic signal.

3. The system as recited in claim 2, wherein said first characteristic is electric field phase and said second characteristic is magnetic field phase.

4. A system for measuring a distance between a first locus and a second locus, the system comprising:

a locator device comprising a receiver and at least one receiving antenna, said locator device for disposition at said second locus, said locator device configured for receiving an electromagnetic signal from a beacon device, said beacon device situated at said first locus, said locator device configured for receiving at a distance from said beacon device within near-field range of said electromagnetic signal;

said locator device configured for distinguishing at least two characteristics of said electromagnetic signal sensed by said locator device at said second locus when said locator device is within a near field range of said electromagnetic signal from said first locus;

said system further comprising a processor, said processor configured for employing said at least two characteristics to effect said measuring in accordance with a predefined relationship between said at least two characteristics and said distance.

5. The system as recited in claim 4, wherein said at least two characteristics of said electromagnetic signal being a first characteristic related to an electric field component of said electromagnetic signal and a second characteristic related to a magnetic field component of said electromagnetic signal.

6. The system as recited in claim 5, wherein said first characteristic is electric field phase and said second characteristic is magnetic field phase.

7. The system as recited in claim 5, wherein said locator device effects said measuring by measuring a phase difference between said at least two characteristics of said electromagnetic signal and employing said phase difference to effect said measuring.

8. The system as recited in claim 4, wherein said locator device effects said measuring by measuring an amplitude difference between said at least two characteristics of said electromagnetic signal and employs said amplitude difference to effect said measuring.

9. A system for determining a position of a locus comprising:

a locator device comprising a receiver and at least one antenna, said locator device for disposition at said locus;

said locator device configured for receiving an electromagnetic signal from a beacon device, said locator device configured for receiving at a distance from said beacon device within near field range of said electromagnetic signal;

said locator device configured for distinguishing at least two characteristics of said electromagnetic signal sensed by said locator device at said locus;

said system further comprising a processor, said processor configured for employing said at least two characteristics to effect said determining said position of said locus in accordance with a predefined calibration relationship between said at least two characteristics and position.

10. The system as recited in claim 9, wherein said at least two characteristics of said electromagnetic signal being a first characteristic related to an electric field component of said electromagnetic signal and a second characteristic related to a magnetic field component of said electromagnetic signal.

11. The system as recited in claim 10, wherein said first characteristic is electric field phase and said second characteristic is magnetic field phase.

12. The system as recited in claim 10, wherein said locator device effects said determining by measuring a phase difference between said at least two characteristics of said electromagnetic signal and employing said phase difference to effect said determining.

13. The system as recited in claim 9, wherein said locator device effects said determining by measuring an amplitude difference between said at least two characteristics of said electromagnetic signal and employs said amplitude difference to effect said determining.

14. The system in accordance with claim 9, wherein the beacon device is a mobile source of electromagnetic radiation.

15. The system in accordance with claim 9, wherein the beacon device operates from a fixed position.

16. The system in accordance with claim 9, wherein the beacon device is an uncooperative source of electromagnetic radiation.

17. The system in accordance with claim 9, further including a data link and a central controller, wherein said locator device conveys information relating to said at least two characteristics to said central controller using said data link.

18. The system in accordance with claim 9, further including a data link and a central controller, wherein said central controller conveys information to said locator device using said data link.

19. The system in accordance with claim 9, wherein the locator device is configured to be carried by a user and provide the user with location specific information.

20. The system in accordance with claim 19, wherein the location specific information relates to a nearby object.

21. The system in accordance with claim 20, wherein the nearby object is for sale, for review, or for evaluation.

22. The system in accordance with claim 20, wherein the location specific information relates to a price for said nearby object.

23. The system in accordance with claim 20, wherein the location specific information is descriptive information for the nearby object.

24. A method for determining distance between a first locus and a second locus, the method comprising the steps of:

(a) a receiving system receiving an electromagnetic signal at said second locus, said electromagnetic signal transmitted from said first locus, said second locus being within near field range of said electromagnetic signal from said first locus;

in no particular order;

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

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

(b) said receiving system comparing said first characteristic and said second characteristic to produce a comparison; and

(c) said receiving system employing said comparison to determine said distance in accordance with a predefined calibration relationship between said comparison and said distance.

25. The method as recited in claim 24, wherein the receiving system is physically distributed and the step of employing said comparison to determine said distance is located at a third locus separate from said second locus.

26. The method as recited in claim 24, wherein said first characteristic is related to an electric field component of said electromagnetic signal and said second characteristic is related to a magnetic field component of said electromagnetic signal.

27. The method as recited in claim 26, wherein said first characteristic is electric field phase and said second characteristic is magnetic field phase.

28. The method as recited in claim 26, wherein said locator device effects said determining by measuring a phase difference between said first characteristic of said electromagnetic signal and said second characteristic of said electromagnetic signal and employing said phase difference to effect said determining.

29. A method for determining a location of a second locus, the method comprising the steps of:

(a) a receiving system receiving an electromagnetic signal at said second locus, said electromagnetic signal transmitted from said first locus, said second locus being within near field range of said electromagnetic signal from said first locus;

in no particular order;

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

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

(b) said receiving system comparing said first characteristic and said second characteristic to produce a comparison; and

(c) said receiving system employing said comparison to determine said location in accordance with a predefined calibration relationship between said comparison and said location.

30. The method as recited in claim 29, wherein the receiving system is physically distributed and the step of employing said comparison to determine said location is located at a third locus separate from said second locus.

31. The method as recited in claim 29, wherein said first characteristic is related to an electric field component of said electromagnetic signal and said second characteristic is related to a magnetic field component of said electromagnetic signal.

32. The method as recited in claim 31, wherein said first characteristic is electric field phase and said second characteristic is magnetic field phase.

33. The method as recited in claim 31, wherein said locator device effects said determining by measuring a phase difference between said first characteristic of said electromagnetic signal and said second characteristic of said electromagnetic signal and employing said phase difference to effect said determining.