Method and apparatus for determining the geographic location of a device

• US 20080074317A1
• Filed: 09/22/2006
• Published: 03/27/2008
• Est. Priority Date: 05/16/2006
• Status: Active Grant

• Current Assignee: TeleCommunication Systems Inc (Comtech Telecommunications Corporation)
• Original Assignee: Andrew LLC (CommScope Holding Company, Inc.)
• Inventors: Harper, Neil, Nicholson, Peter
• Granted Patent: US 7,733,268 B2
• Time in Patent Office: Days
• US Class Current: 342/357.02
• CPC Class Codes: G01S 19/20 Integrity monitoring, fault detection or fault isolation of space segment
• CPC Class Codes: G01S 19/23 Testing, monitoring, correcting or calibrating of receiver elements
• CPC Class Codes: G01S 19/40 Correcting position, velocity or attitude

Abstract

A method and apparatus for determining the location of a device from signals provided by a plurality of satellites. A device receives a first plurality of signals comprising one signal from each of a first plurality of satellites and determines a first location of the device as a function of the first plurality of signals. The device then determines a second location thereof as a function of a second plurality of signals if the first location is not within a predetermined threshold. The second plurality of signals is a first subset of the first plurality of signals.

Claims

1. A method for determining the location of a device comprising the steps of:

(a) receiving a first plurality of signals comprising one signal from each of a first plurality of satellites;

(b) determining a first location of the device as a function of the first plurality of signals; and

(c) determining a second location of the device as a function of a second plurality of signals if the first location is not within a predetermined threshold,

wherein the second plurality of signals is a first subset of the first plurality of signals.

2. The method of claim 1 wherein a cardinality of the second plurality of signals is at least four.

3. The method of claim 1 further comprising the step of:

(d) determining a third location of the device as a function of a third plurality of signals if the second location is not within the predetermined threshold,

wherein the third plurality of signals is a second subset of the first plurality of signals.

4. The method of claim 3 wherein a cardinality of the second plurality of signals is the same as a cardinality of the third plurality of signals.

5. The method of claim 3 wherein a cardinality of the second plurality of signals is greater than a cardinality of the third plurality of signals.

6. In a method for eliminating erroneous satellite signals in a position calculation for a device receiving a first plurality of signals from a first plurality of satellites, the improvement comprising the steps of determining a first position calculation of the device as a function of the first plurality of signals and determining a second position calculation of the device as a function of a second plurality of signals if the first calculation is not within a predetermined threshold, wherein the second plurality of signals is a first subset of the first plurality of signals.

7. The method of claim 6 wherein the device is receiving signals from a cellular network.

8. The method of claim 7 wherein a position calculation of the device is a function of signals provided by the cellular network.

9. The method of claim 6 wherein the satellites are part of a Global Navigation Satellite System (“

GNSS”

).

10. The method of claim 9 wherein the GNSS is selected from the group consisting of:

Global Positioning System (“

GPS”

), Galileo, GLONASS, and Quasi-Zenith Satellite System (“

QZSS”

).

11. The method of claim 6 wherein the device is a mobile unit.

12. The method of claim 11 wherein the mobile unit is selected from the group consisting of:

cellular device, text messaging device, computer, portable computer, vehicle locating device, vehicle security device, communication device, and wireless transceiver.

13. The method of claim 6 wherein a cardinality of the second plurality of signals is at least four.

14. The method of claim 6 further comprising the step of determining a third location of the device as a function of a third plurality of signals if the second location is not within the predetermined threshold, wherein the third plurality of signals is a second subset of the first plurality of signals.

15. The method of claim 14 wherein a cardinality of the second plurality of signals is the same as a cardinality of the third plurality of signals.

16. The method of claim 14 wherein a cardinality of the second plurality of signals is greater than a cardinality of the third plurality of signals.

17. In a method for determining the location of a device receiving signals from each of a plurality of satellites, the device having determined a first location from the received signals, the improvement comprising the steps of:

(a) comparing a quality of the first location of the device with a predetermined threshold; and

(b) determining a second location of the device from a first subset of the received signals if the quality of the first location is not within the predetermined threshold.

18. The method of claim 17 wherein the quality is defined by a lowest sum of the squared residuals.

19. The method of claim 17 wherein at least one of the received signals is provided by a cellular network.

20. The method of claim 19 wherein the quality is a function of information provided by the cellular network.

21. The method of claim 17 wherein the satellites are part of a Global Navigation Satellite System (“

GNSS”

).

22. The method of claim 21 wherein the GNSS is selected from the group consisting of:

Global Positioning System (“

GPS”

), Galileo, GLONASS, and Quasi-Zenith Satellite System (“

QZSS”

).

23. The method of claim 17 wherein the device is a mobile unit.

24. The method of claim 23 wherein the mobile unit is selected from the group consisting of:

cellular device, text messaging device, computer, portable computer, vehicle locating device, vehicle security device, communication device, and wireless transceiver.

25. The method of claim 17 further comprising the step of determining a third location of the device as a function of a second subset of the received signals if the quality of the second location is not within the predetermined threshold.

26. The method of claim 25 wherein a cardinality of the signals defining the first subset is at least four.

27. The method of claim 25 wherein a cardinality of the signals defining the first subset is greater than the cardinality of the signals defining the second subset.

28. A method for determining the location of a device comprising the steps of:

(a) receiving a plurality of signals from a plurality of satellites;

(b) generating estimates of a location of the device using combinations of the plurality of signals; and

(c) selecting an estimate as defined by a quality of each of the combinations.

29. The method of claim 28 wherein a cardinality of the plurality of signals is at least four.

30. The method of claim 28 wherein the satellites are part of a Global Navigation Satellite System (“

GNSS”

).

31. The method of claim 30 wherein the GNSS is selected from the group consisting of:

Global Positioning System (“

GPS”

), Galileo, GLONASS, and Quasi-Zenith Satellite System (“

QZSS”

).

32. The method of claim 28 wherein the quality is a function of a sum of the squared residuals.

33. The method of claim 28 wherein the device is a mobile unit.

34. The method of claim 33 wherein the mobile unit is selected from the group consisting of:

cellular telephone, text messaging device, computer, portable computer, vehicle locating device, vehicle security device, communication device, and wireless transceiver.

35. The method of claim 33 wherein the mobile unit receives signals from a cellular network.

36. The method of claim 35 wherein the estimate of a location of the device is a function of signals provided by the cellular network.

37. A device comprising:

a receiver for receiving a first plurality of signals comprising one signal from each of a first plurality of satellites;

a means for determining a first location of the device as a function of the first plurality of signals; and

a means for determining a second location of the device as a function of a second plurality of signals if the first location is not within a predetermined threshold, wherein the second plurality of signals is a first subset of the first plurality of signals.

38. The device of claim 37 further comprising a means for determining a third location of the device as a function of a third plurality of signals if the second location is not within the predetermined threshold, wherein the third plurality of signals is a second subset of the first plurality of signals.

39. The device of claim 37 wherein the satellites are part of a Global Navigation Satellite System (“

GNSS”

).

40. The device of claim 39 wherein the GNSS is selected from the group consisting of:

Galileo, GLONASS, and Quasi-Zenith Satellite System (“

QZSS”

).

41. The device of claim 37 wherein the satellites are Global Positioning System (“

GPS”

) satellites.

42. The device of claim 37 wherein the predetermined threshold is a function of ephemeris information transmitted by one of the satellites.

43. The device of claim 37 wherein the predetermined threshold is a function of a lowest sum of the squared residuals.

44. The device of claim 37 wherein the device is a mobile unit.

45. The device of claim 44 wherein the mobile unit is selected from the group consisting of:

cellular device, text messaging device, computer, portable computer, vehicle locating device, vehicle security device, communication device, and wireless transceiver.

46. The device of claim 45 wherein the mobile unit is adaptable to receive signals from a cellular network.

47. The device of claim 46 wherein the predetermined threshold is a function of information received from the cellular network.

48. A system for determining a location of a device from signals received from a plurality of Global Navigation Satellite System (“

GNSS”

) satellites comprising;

a receiver for receiving signals from each of a plurality of satellites;

a means for determining a first location of the device as a function of a quality of the received signals; and

a means for determining a second location of the device as a function of a subset of said received signals if said quality is not within a predetermined threshold.

49. The system of claim 48 wherein the satellites are part of a Global Navigation Satellite System (“

GNSS”

).

50. The system of claim 49 wherein the GNSS is selected from the group consisting of:

Galileo, GLONASS, and Quasi-Zenith Satellite System (“

QZSS”

).

51. The system of claim 48 wherein the satellites are Global Positioning System (“

GPS”

) satellites.

52. The system of claim 48 wherein said quality is a function of ephemeris information transmitted by at least one satellite.

53. The system of claim 48 wherein said quality is a function of a lowest sum of the squared residuals determined from said signals.

54. The system of claim 48 wherein the device is a mobile unit.

55. The system of claim 54 wherein the mobile unit is selected from the group consisting of:

cellular device, text messaging device, computer, portable computer, vehicle locating device, vehicle security device, communication device, and wireless transceiver.

56. The system of claim 54 wherein the mobile unit receives signals from a cellular network.

57. The system of claim 56 wherein the location of the device is a function of information provided by the cellular network.

58. A method of calculating the position of a device comprising the steps of:

(a) receiving a first plurality of observations from a first plurality of satellites;

(b) determining a first position of the device as a function of a quality of the first plurality of observations;

(c) if the quality of the first plurality of observations fails to meet the predefined threshold then;

(i) determining a second position of the device as defined by a quality of a second plurality of observations, the second plurality being a subset of the first plurality of observations,

(ii) if the quality of the second plurality of observations fails to meet the predefined threshold then repeating step (i) using incrementally decreasing subsets of observations until a predetermined criteria is achieved.

59. The method of claim 58 wherein the criteria is a cardinality of observations is at least four.

60. The method of claim 58 wherein the criteria is the quality meets the predefined threshold.

61. The method of claim 58 wherein the criteria is the quality of all combinations of satellite observations have failed to meet the predefined threshold.

62. The method of claim 58 wherein the quality is a function of a lowest sum of the squared residuals.

63. The method of claim 58 wherein the device is receiving signals from a cellular network.

64. The method of claim 63 wherein the quality is a function of information provided from the cellular network.

65. The method of claim 58 wherein the satellites are part of a Global Navigation Satellite System (“

GNSS”

).

66. The method of claim 65 wherein the GNSS is selected from the group consisting of:

Global Positioning System (“

GPS”

), Galileo, GLONASS, and Quasi-Zenith Satellite System (“

QZSS”

).

67. The method of claim 58 wherein the device is a mobile unit.

68. The method of claim 67 wherein the mobile unit is selected from the group consisting of:

cellular device, text messaging device, computer, portable computer, vehicle locating device, vehicle security device, communication device, and wireless transceiver.