Navigation system

• US 20050215269A1
• Filed: 02/17/2005
• Published: 09/29/2005
• Est. Priority Date: 02/17/2004
• Status: Active Grant

• Current Assignee: Hailo Technologies, LLC (2S Ventures, LLC)
• Original Assignee: JADI, Inc.
• Inventors: Cheok, Ka C., Smid, G. Edzko
• Granted Patent: US 7,403,783 B2
• Time in Patent Office: Days
• US Class Current: 455/456.100
• CPC Class Codes: G01S 5/0284 Relative positioning
• CPC Class Codes: G01S 5/0289 of multiple transceivers, e.g. in ad hoc networks
• CPC Class Codes: G01S 5/06 Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements G01S5/12 takes precedence
• CPC Class Codes: G01S 5/10 Position of receiver fixed by co-ordinating a plurality of position lines defined by path-difference measurements , e.g. omega or decca systemsG01S5/12 takes precedence ; beacons and receivers cooperating therewith G01S1/306, G01S1/308
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

The present invention relates to a method of determining the location of a target. The method includes initializing a set of base stations to determine their location relative to each other. At the target, the time of arrival of at least one signal from each of the plurality of base stations Is measured. From this, the location of the target relative to the plurality of base stations may be directly calculated using a closed solution. In one embodiment, a time of arrival technique is used and in another embodiment a time difference of arrival technique is used. Preferably an ultra-wide band frequency is utilized.

Claims

1. A method of determining the location of a target, comprising:

initializing a plurality of base stations to determine their relative location to each other;

measuring, at the target, the time of arrival of at least one signal from each of the plurality of base stations;

calculating directly the location of the target relative to the plurality of base stations using a closed solution, where the plurality of base stations is at three when a time of arrival technique is used and wherein the plurality of base stations is at least four when a time difference of arrival technique is used.

2. The method of claim 1, wherein the target calculates it own position.

3. The method of claim 1, wherein each of the base stations is a mobile base station.

4. The method of claim 1, wherein the initializing step comprises using a time of arrival technique to determine the location of each base station.

5. The method of claim 1, further comprising initializing the base stations to determine their global geographic location.

6. The method of claim 1, wherein the measuring and calculating steps are repeated at least 50 times a sec.

7. The method of claim 1, wherein the measuring and calculating steps are repeated at least 200 times a sec.

8. The method of claim 1, wherein the calculating step comprises using a time of arrival technique to calculate the location of the target.

9. The method of claim 1, wherein the calculating step comprises using a time difference of arrival technique to calculate the location of the target.

10. The method of claim 1, wherein the measuring step comprises transmitting a unique PN code from each base station.

11. The method of claim 1, wherein the measuring step comprises using a UWB signal with a chiprate between about 0.1 and about 10 Gbits.sec.

12. The method of claim 1, wherein the measuring step comprises using a DS-CDMA communication scheme.

13. The method of claim 1, wherein the measuring step comprises oversampling the received signal between about 0.3 and about 30 giga-samples/sec.

14. The method of claim 1, wherein the measuring step comprises oversampling with a digital sampler or an analog-to-digital converter.

15. The method of claim 1 wherein the calculating step yields a location of the target with a resolution between about 0.01 and about 1.0 meter.

16. The method of claim 1 wherein the calculating step yields a location of the target with an accuracy between about 0.01 and about 1.0 meter.

17. A system for determining the location of a receiver, comprising:

at least three base stations and at least one target for a TOA technique and at least four base stations and a target for a TDOA technique,

each base station comprising at least one GHF UWB transmitter,

wherein at least one base station and the target are mobile and wherein the target is capable of calculating its location using a closed form solution based.

18. The system of claim 17, wherein the target is an unmanned ground vehicle comprising a mine sweeper.

19. The system of claim 17, wherein the target is an unmanned aerial vehicle comprising an aerial drone.

20. The system of claim 17, wherein the target is an unmanned sea vehicle.