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

• US 20020196188A1
• 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 6,580,393 B2
• Time in Patent Office: Days
• US Class Current: 342/453
• CPC Class Codes: G01S 3/02 using radio waves
• CPC Class Codes: G01S 5/0269 Inferred or constrained positioning, e.g. employing knowledge of the physical or electromagnetic environment, state of motion or other contextual information to infer or constrain a position
• 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

A system and method determines the location of a transmitter. At least one receiver receives a signal from the transmitter and at least one proxy receiver is an object that reflects and/or refracts a signal along an arriving path to the at least one receiver. A processor is operative with the at least one receiver and determines the location of the at least one proxy receiver based on one of querying a look-up table or extracting image features from the mapping system and determining the location of the transmitter based on the time of arrival and at least one of angle of arrival of signals from the at least one proxy receiver and transmitter.

Claims

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

a transmitter to be located that transmits a signal;

at least one receiver that receives a signal from the transmitter;

at least one proxy receiver as an object that reflects and/or refracts a signal along an arriving path to the at least one receiver; and

a processor operative with the at least one receiver for determining the location of the at least one proxy receiver based on one of querying a look-up table or extracting image features from a mapping system, and determining the location of the transmitter based on the Time of Arrival and at least one of Angle of Arrival of signals from the at least one proxy receiver and transmitter.

2. A system according to claim 1, wherein said at least one proxy receiver comprises two proxy receivers.

3. A system according to claim 1, and further comprising a graphics application program and application programming interface, and a three-dimensional model of a geographic area for determining the location of proxy receivers based on signals received along the arriving path to the receiver.

4. A system according to claim 3, and further comprising a site model clip map image containing composite maps in a spatially correct position.

5. A system according to claim 4, wherein said composite maps comprise texture maps.

6. A system according to claim 1, wherein said transmitter comprises a mobile transmitting unit.

7. A system according to claim 1, wherein said signal comprises at least one line of sight signal from the transmitter to a receiver.

8. A system according to claim 1, wherein said signal comprises a plurality of signals from a plurality of proxy receivers.

9. A system according to claim 1, wherein said at least one proxy receiver comprises at least one natural landmark.

10. A system according to claim 9, wherein said at least one proxy receiver comprises at least one earth elevation.

11. A system according to claim 1, wherein said at least one proxy receiver comprises at least one man-made structure.

12. A system according to claim 11, wherein said at least one proxy receiver comprises at least one building.

14. A method according to claim 13, and further comprising the step of determining the location of the at least one reflector and/or refractor by one of querying a look-up table or extracting image features.

15. A method according to claim 13, wherein said transmitter comprises a mobile transmitting unit.

16. A method according to claim 13, wherein said signal comprises a line of sight signal from the transmitter to the receiver.

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

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

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

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

21. A method according to claim 13, and further comprising at least two proxy receivers.

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

transmitting a signal from a transmitter having an unknown location to at least one receiver;

determining the location of at least one reflector and/or refractor of the signal along an arriving path to the at least one receiver;

establishing a proxy receiver at the at least one reflector and/or refractor; 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 at least one proxy receiver and a transmitter.

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

transmitting a signal from a transmitter having an unknown location to at least one receiver;

determining the location of at least one reflector and/or refractor of the signal along an arriving path to a receiver by extracting image features from a mapping system;

establishing at least one proxy receiver at the reflector and/or refractor; and

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

23. A method according to claim 22, wherein said step of extracting image features comprises the step of creating three-dimensional models and determining the signal reflectivity of the models.

24. A method according to claim 23, wherein said step of extracting image features comprises the step of creating three-dimensional models from imagery in a texture mapping system.

25. A method according to claim 24, wherein said step of creating three-dimensional models comprises the step of creating a site model clip map image from a rectangle of textures.

26. A method according to claim 22, wherein said at least one receiver comprises two receivers.

27. A method according to claim 22, wherein said transmitter comprises a mobile transmitting unit.

28. A method according to claim 22, wherein said signal comprises a line of sight signal from the transmitter to the receiver.

29. A method according to claim 22, wherein said at least one proxy receiver comprises at least one natural landmark.

30. A method according to claim 29, wherein said at least one proxy receiver comprises at least one earth elevation.

31. A method according to claim 22, wherein said at least one proxy receiver comprises at least one man-made structure.

32. A method according to claim 22, wherein said at least one proxy receiver comprises at least one building.