System and method for determining the location of a transmitter using passive reflectors or refractors as proxy receivers

• US 20020196187A1
• Filed: 06/25/2001
• Published: 12/26/2002
• Est. Priority Date: 06/25/2001
• Status: Active Grant

• Current Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Original Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Inventors: Holt, Brian
• Granted Patent: US 6,608,593 B2
• Time in Patent Office: Days
• US Class Current: 342/453
• CPC Class Codes: G01S 5/0268 by deriving positions from different combinations of signals or of estimated positions in a single positioning system
• CPC Class Codes: G01S 5/0273 using multipath or indirect path propagation signals in position determination
• CPC Class Codes: G01S 5/12 by co-ordinating position lines of different shape, e.g. hyperbolic, circular, elliptical or radial

Abstract

The location of a transmitter can be determined using a proxy receiver, such as a natural landmark or manmade structure, which reflects and/or refracts the signal from a transmitter toward a receiver. A processor is operatively connected to the receiver and determines the location of the transmitter based on a multilateration calculation that includes the Time of Arrival of the transmitted signal at the proxy receiver and the known or calculated location of the proxy receiver as inputs.

Claims

1. A system for determining the location of a transmitter comprising:

a transmitter to be located that transmits a signal;

a receiver that receives a signal from a transmitter;

a proxy receiver that reflects and/or refracts a signal from the transmitter toward the one receiver; and

a processor operative with the receiver for determining the location of the transmitter based on the Time of Arrival and at least one of the Angle of Arrival of the signals received from the proxy receiver and the transmitter.

2. A system according to claim 1 wherein said transmitter comprises a mobile unit.

3. A system according to claim 1 wherein said signal comprises a radio frequency signal.

4. A system according to claim 1 wherein signal is a line of sight signal from the transmitter to the receiver.

5. A system according to claim 1 wherein said proxy receiver comprises a natural landmark.

6. A system according to claim 5 wherein said proxy receiver comprises an earth elevation.

7. A system according to claim 1 wherein said proxy receiver comprises a man-made structure.

8. A system according to claim 7 wherein said proxy receiver comprises a building.

9. A system according to claim 1 wherein said processor determines the location by computing a set of locations corresponding to the Time Difference of Arrival of the signal from the transmitter and the signal received from the proxy receiver.

10. A system according to claim 1 wherein said Angle of Arrival of the signal from transmitter to the receiver is used for determining the location of the transmitter.

11. A system according to claim 1 and further comprising a plurality of receivers for receiving the signal.

12. A system according to claim 11 wherein said plurality of receivers comprises two receivers.

14. A method according to claim 13 wherein said transmitter comprises a mobile unit.

15. A method according to claim 13 wherein said signal is a line of sight signal from the transmitter to the receiver.

16. A method according to claim 13 wherein said proxy receiver comprises a natural landmark.

17. A method according to claim 16 wherein said proxy receiver comprises an earth elevation.

18. A method according to claim 13 wherein said proxy receiver comprises a man-made structure.

19. A method according to claim 18 wherein said proxy receiver comprises a building.

20. A method according to claim 13 and further comprising the step of determining the location by computing a set of locations corresponding to the Time Difference of Arrival of the signal from the transmitter and the proxy receiver.

21. A method according to claim 13 wherein said Angle of Arrival of said signal from the transmitter is a line of sight signal and is used for determining the location of the transmitter.

13. A method for determining the location of a transmitter comprising the steps of:

receiving a signal from the transmitter within a receiver;

receiving the signal from an object acting as a proxy receiver that has reflected and/or refracted the signal from the transmitter; and

determining the location of the transmitter based on the Time of Arrival and at least one Angle of Arrival of the signals from the proxy receiver and transmitter.

22. A method for determining the location of a transmitter comprising the steps of:

receiving a signal from the transmitter within an omnidirectional antenna located at a receiver;

receiving the signal into a narrow beam antenna of the receiver that is directed at a known object acting as a proxy receiver that has reflected and/or refracted the signal from the transmitter; and

determining the location of the transmitter based on the Time of Arrival and at least one Angle of Arrival of the received signals.

23. A method according to claim 22 wherein said signal is a line of sight signal from the transmitter to the receiver.

24. A method according to claim 22 wherein the location of proxy receiver is known.

25. A method according to claim 22 wherein said transmitter comprises a mobile unit.

26. A method according to claim 22 wherein said proxy receiver comprises a natural landmark.

27. A method according to claim 26 wherein said proxy receiver comprises an earth elevation.

28. A method according to claim 22 wherein said proxy receiver comprises a man-made structure.

29. A method according to claim 26 wherein said proxy receiver comprises a building.

30. A method according to claim 26 and further comprising the step of determining the location of the transmitter by computing a set of locations corresponding to the Time Difference of Arrival of the signal from the transmitter and the proxy receiver.

31. A method according to claim 26 wherein said Angle of Arrival of said signal received in the omnidirectional antenna is used for determining the location of the transmitter.