GENERALIZED HIGH PERFORMANCE NAVIGATION SYSTEM

• US 20080059059A1
• Filed: 05/16/2007
• Published: 03/06/2008
• Est. Priority Date: 05/18/2006
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Whelan, David, Cohen, Clark, Gutt, Gregory, Ferrell, Barton, Brumley, Robert
• Granted Patent: US 8,296,051 B2
• Time in Patent Office: Days
• US Class Current: 701/207
• CPC Class Codes: G01C 21/206 specially adapted for indoor navigation
• CPC Class Codes: G01S 19/02 Details of the space or ground control segments
• CPC Class Codes: G01S 19/07 providing data for correcting measured positioning data, e.g. DGPS [differential GPS] or ionosphere corrections
• CPC Class Codes: G01S 19/10 providing dedicated supplementary positioning signals
• CPC Class Codes: G01S 19/11 wherein the cooperating elements are pseudolites or satellite radio beacon positioning system signal repeaters
• CPC Class Codes: G01S 19/12 wherein the cooperating elements are telecommunication base stations
• CPC Class Codes: G01S 19/49 whereby the further system is an inertial position system, e.g. loosely-coupled

Abstract

A generalized high performance navigation system is provided using low earth orbit (LEO) satellites. In one embodiment, a method of performing navigation includes receiving a LEO signal from a LEO satellite. The method also includes decoding a navigation signal from the LEO signal. The method further includes receiving first and second ranging signals from first and second ranging sources, respectively. In addition, the method includes determining calibration information associated with the first and second ranging sources. The method also includes calculating a position using the navigation signal, the first and second ranging signals, and the calibration information.

Claims

1. A method of performing navigation, the method comprising:

receiving a low earth orbit (LEO) signal from a LEO satellite;

decoding a navigation signal from the LEO signal;

receiving first and second ranging signals from first and second ranging sources, respectively;

determining calibration information associated with the first and second ranging sources; and

calculating a position using the navigation signal, the first and second ranging signals, and the calibration information.

2. The method of claim 1, wherein the LEO signal comprises a communication signal and the navigation signal, wherein the LEO satellite is a communication satellite configured to provide the LEO signal.

3. The method of claim 2, wherein the LEO satellite is selected from the group consisting of an Iridium satellite and a Globalstar satellite.

4. The method of claim 2, wherein the navigation signal comprises a pseudo random noise (PRN) signal encoded in a plurality of channels of the LEO signal.

5. The method of claim 1, wherein the navigation signal is selected from the group consisting of a military navigation signal, a commercial navigation signal, and a civilian navigation signal.

6. The method of claim 1, wherein at least one of the ranging signals is selected from the group consisting of a cellular telephone signal, a television signal, and a global positioning system (GPS) signal.

7. The method of claim 1, wherein the calibration information is encoded in the LEO signal, wherein the determining comprises decoding the calibration information from the LEO signal.

8. The method of claim 1, wherein the calibration information comprises code timing, carrier phase, data bits, and symbol phase.

9. The method of claim 1, wherein the determining comprises receiving the calibration information from a reference station in communication with the ranging sources.

10. The method of claim 1, wherein the determining comprises receiving the calibration information through a cellular network.

11. The method of claim 1, further comprising:

receiving a replica of the navigation signal through a cellular network; and

calculating the position using the replica of the navigation signal, the first and second ranging signals, and the calibration information.

12. The method of claim 1, wherein the method is performed by a device selected from the group consisting of a handheld navigation device, a vehicle-based navigation device, and an aircraft-based navigation device.

13. The method of claim 1, wherein the decoding comprises:

selecting a plurality of channels of the LEO signal carrying the navigation signal, wherein the navigation signal comprises navigation data encoded in a navigation carrier signal, wherein the navigation carrier signal is distributed over the channels by a pseudo random noise (PRN) encoding;

despreading the navigation signal from the channels; and

demodulating the navigation data and the navigation carrier from the navigation signal.

14. The method of claim 1, wherein the decoding comprises decrypting the navigation signal using a distributed encryption key associated with an area of operations.

15. The method of claim 1, wherein at least one of the ranging signals is a single-frequency global positioning system (GPS) L1 signal.

16. The method of claim 1, wherein performance of the method is conditioned on possession of an encryption key by a navigation device.

17. A navigation device comprising:

an antenna adapted to receive a low earth orbit (LEO) signal from a LEO satellite and receive first and second ranging signals from first and second ranging sources, respectively;

a receiver processor adapted to downconvert the LEO signal for further processing; and

a navigation processor adapted to decode a navigation signal from the LEO signal, and adapted to calculate a position of the navigation device using the navigation signal, the first and second ranging signals, and calibration information associated with the first and second ranging sources.

18. The navigation device of claim 17, wherein the LEO signal comprises a communication signal and the navigation signal, wherein the LEO satellite is a communication satellite configured to provide the LEO signal.

19. The navigation device of claim 18, wherein the LEO satellite is selected from the group consisting of an Iridium satellite and a Globalstar satellite.

20. The navigation device of claim 18, wherein the navigation signal comprises a pseudo random noise (PRN) signal encoded in a plurality of channels of the LEO signal.

21. The navigation device of claim 17, wherein the navigation signal is selected from the group consisting of a military navigation signal, a commercial navigation signal, and a civilian navigation signal.

22. The navigation device of claim 17, wherein at least one of the ranging signals is selected from the group consisting of a cellular telephone signal, a television signal, and a global positioning system (GPS) signal.

23. The navigation device of claim 17, wherein the calibration information is encoded in the LEO signal, wherein the navigation processor is adapted to decode the calibration information from the LEO signal.

24. The navigation device of claim 17, wherein the calibration information comprises code timing, carrier phase, data bits, and symbol phase.

25. The navigation device of claim 17, wherein the navigation device is adapted to receive the calibration information from a reference station in communication with the ranging sources.

26. The navigation device of claim 17, wherein the calibration information is received through a cellular network.

27. The navigation device of claim 17, wherein the antenna is adapted to receive a replica of the navigation signal through a cellular network, wherein the navigation processor is adapted to calculate the position using the replica of the navigation signal, the first and second ranging signals, and the calibration information.

28. The navigation device of claim 17, wherein the navigation device is selected from the group consisting of a handheld navigation device, a vehicle-based navigation device, and an aircraft-based navigation device.

29. The navigation device of claim 17, wherein the navigation processor is adapted to:

select a plurality of channels of the LEO signal carrying the navigation signal, wherein the navigation signal comprises navigation data encoded in a navigation carrier signal, wherein the navigation carrier signal is distributed over the channels by a pseudo random noise (PRN) encoding;

despread the navigation signal from the channels; and

demodulate the navigation data and the navigation carrier from the navigation signal.

30. The navigation device of claim 17, wherein the navigation processor is adapted to decrypt the navigation signal using a distributed encryption key associated with an area of operations.

31. The navigation device of claim 17, wherein at least one of the ranging signals is a single-frequency global positioning system (GPS) L1 signal.

32. A navigation device comprising:

means for receiving a low earth orbit (LEO) signal from a LEO satellite;

means for decoding a navigation signal from the LEO signal;

means for receiving first and second ranging signals from first and second ranging sources, respectively;

means for determining calibration information associated with the first and second ranging sources; and

means for calculating a position using the navigation signal, the first and second ranging signals, and the calibration information.

33. The navigation device of claim 32, wherein the navigation device is part of a navigation and communication system comprising the LEO satellite, a reference network, and the first and second ranging sources.

34. The navigation device of claim 32, means for estimating ionosphere effects using a single-frequency global positioning system (GPS) L1 signal.

35. The navigation device of claim 32, further comprising means for providing three-dimensional autoland guidance for an aircraft using the navigation signal and the first signal, wherein the first ranging source is a satellite.

36. The navigation device of claim 32, further comprising means for providing vertical autoland guidance using the navigation signal.

37. The navigation device of claim 32, further comprising means for providing two-dimensional vehicle guidance using an altitude map and the navigation signal.

38. The navigation device of claim 32, further comprising means for implementing Receiver Autonomous Integrity Monitoring (RAIM).