Location system

• US 7,053,831 B2
• Filed: 10/20/2004
• Issued: 05/30/2006
• Est. Priority Date: 10/20/2003
• Status: Active Grant

• Current Assignee: Consortium P Incorporated
• Original Assignee: Radianse Incorporated (Airpointe Corp.)
• Inventors: Donovan, Kimberly, Lathrop, Olin, Tessier, Paul, Dempsey, Michael K., Gaudet, Phil
• Primary Examiner(s): Phan, Dao
• Application Number:
  US10/970,197
• Publication Number:
  US 20050128143A1
• Time in Patent Office: 587 Days
• Field of Search: 342/451, 342/457, 342/458, 342/463, 455/456.1, 455/456.6, 455/457
• US Class Current: 342/463
• CPC Class Codes: G01S 5/12 by co-ordinating position lines of different shape, e.g. hyperbolic, circular, elliptical or radial

Abstract

Systems and methods for allowing the location of transmitter to be determined (approximated) without requiring its distance from a receiver to be precisely known. Methods for determining a location of a transmitter without precise distance calculations. In one embodiment, a method is disclosed having the steps of: for a receiver, estimate a first zone a first transmitter is in; for remaining receivers that can receive a given transmitter, each estimate a second zone a first transmitter is in; and determine if there are overlaps in any of the zones. In another embodiment a potential target area is defined wherein the location of a transmitter can estimated.

Claims

1. A method for determining location of an object, comprising the steps of:

identifying receivers that received a signal from a transmitter;

generating one or more line segments connecting the identified receivers;

determining zones around identified receivers;

generating lines through intersections of zones and the one or more lines;

designating the area defined by lines as the potential target area; and

estimating a target location within the potential target area.

2. The method of claim 1, wherein the step of generating lines comprises generating secants through the intersections between the line segments and the zones for each zone.

3. The method of claim 1, wherein the step of generating lines comprises generating tangents at the intersections between the line segments and the zones for each zone.

4. The method of claim 1, wherein said zones are rings.

5. The method of claim 1, wherein said zone is defined as a sphere.

6. The method of claim 1, wherein a size of said zones is scalable.

7. The method of claims 1, wherein said zones are determined using received signal strength indication.

8. The method of claims 1, wherein said zones are determined using time of arrival of one or more signals.

9. The method of claim 1, wherein the step of estimating a target location within the potential target area comprises finding the center of the potential target area.

10. A method for determining location of an object, comprising the steps of:

identifying receivers that received a signal from a transmitter;

generating one or more lines segments connecting the identified receivers;

determining zones around the identified receivers;

or

generating lines through intersections of zones and the one or more line segments;

designating the area defined by the lines as the potential target area; and

determining center of potential target area.

11. The method of claim 10, wherein the step of generating lines comprises generating secants through the intersections between the line segments and the zones for each zone.

12. The method of claim 10, wherein the step of generating lines comprises generating tangents at the intersections between the line segments and the zones for each zone.

13. The method of claim 10, wherein said zone is defined as a ring.

14. The method of claim 10, wherein said zone is defined as a sphere.

15. The method of claim 10, wherein a size of said zones is scalable.

16. The method of claims 10, wherein said zones are determined using received signal strength indication.

17. The method of claims 10, wherein said zones are determined using time of arrival of one or more signals.

18. In a computing device, a method for determining location of an object, comprising the steps of:

identifying receivers that received a signal from a transmitter;

generating one or more line segments connecting the identified receivers;

determining zones around the identified receivers;

generating lines through intersections of zones and the one or more line segments;

designating the area defined by lines as the potential target area; and

determining the center of the potential target area.

19. A computer program product holding instructions executable in a computer for determining location of an object, the instructions comprising the steps of:

identifying receivers that received a signal from a transmitter;

generating one or more line segments connecting the identified receivers;

determining zones around the identified receivers;

generating lines through intersections of zones and the one or more line segments;

designating the area defined by lines as the potential target area; and

determining the center of the potential target area.