Locating a roving position receiver in a location network

• US 7,859,462 B2
• Filed: 08/18/2006
• Issued: 12/28/2010
• Est. Priority Date: 11/02/2001
• Status: Active Grant

• Current Assignee: Locata Corporation Pty Ltd
• Original Assignee: Locata Corporation Pty Ltd
• Inventors: Small, David
• Primary Examiner(s): PHAN, DAO LINDA
• Application Number:
  US11/506,468
• Publication Number:
  US 20070040739A1
• Time in Patent Office: 1,593 Days
• Field of Search: 342/357.01, 342/357.03, 342/357.09, 342/357.15, 342/450, 342/457, 342463-465, 455/456.1, 455/456.2, 701/213, 701/215
• US Class Current: 342/450
• CPC Class Codes: G01S 1/24 the synchronised signals being pulses or equivalent modulations on carrier waves and the transit times being compared by measuring the difference in arrival time of a significant part of the modulations , e.g. LORAN systems
• CPC Class Codes: G01S 19/10 providing dedicated supplementary positioning signals
• CPC Class Codes: G01S 19/23 Testing, monitoring, correcting or calibrating of receiver elements
• CPC Class Codes: G01S 19/256 relating to timing, e.g. time of week, code phase, timing offset
• CPC Class Codes: G01S 19/43 using carrier phase measurements, e.g. kinematic positioning; using long or short baseline interferometry
• CPC Class Codes: G01S 5/0081 Transmission between base stations
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence
• CPC Class Codes: G01S 5/0226 Transmitters
• CPC Class Codes: G01S 5/0289 of multiple transceivers, e.g. in ad hoc networks
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: G01S 5/145 Using a supplementary range measurement, e.g. based on pseudo-range measurements
• CPC Class Codes: H04W 56/0015 one node acting as a reference for the others
• CPC Class Codes: H04W 56/0065 using measurement of signal travel time

Abstract

The system comprises a positioning-unit device (PUD) that receives, from other PUDs and other signal sources, one or more positioning signals, which each have carrier, code and data componcuts. In response to the received positioning signals and using their known locations, the PUD generates a unique positioning signal, which similarly has carrier, code and data components, all of which are respectively chronologically synchronized to the counterpart components of the received positioning signals. Once synchronized, other PUDs entering the network use the unique positioning signal as a reference, providing a time-coherent network of positioning signals that propagate a reference timebase over a geographical area. The invention also includes a roving position receiver that generates both code and carrier-based single point position determinations by making respective range measurements for each of the received chronologically synchronized code and carrier components, without the requirement for differential correction or absolute time accuracy within the network.

Claims

1. A method for determining the position of a roving position receiver in a positioning system comprising at least one reference transmitter, and at least one positioning-unit device, said method comprising the steps of:

a) each of said at least one reference transmitter generating and transmitting reference positioning signals according to the timebase of said at least one reference transmitter, wherein each of said at least one reference transmitters is at a known location;

b) each of said at least one positioning-unit device;

i) receiving and interpreting signals transmitted by either said at least one reference transmitter or said at least one positioning-unit device or both said at least one reference transmitter and said at least one positioning-unit device;

ii) determining a reference positioning signal propagation delay between said at least one reference transmitter and said positioning-unit device;

iii) generating and transmitting a unique positioning signal;

iv) receiving and interpreting said unique positioning signal;

v) comparing said received and interpreted signals from step (i) and said unique positioning signal from step (iv) to deduce a transmission difference;

vi) continuously adjusting said generation and transmission of said unique positioning signal according to;

a) said deduced transmission difference from step (v); and

b) said reference positioning signal propagation delay from step (ii);

such that said unique positioning signal is chronologically synchronized to said reference positioning signals;

c) said roving position receiver receiving either;

i) said chronologically synchronized unique positioning signals;

or

ii) both said reference positioning signals and said chronologically synchronized unique positioning signals; and

subsequently calculating its own position without the requirement of differential corrections.

2. A method according to claim 1, wherein:

a) said at least one reference transmitter is further configured to generate and transmit a plurality of frequency-diverse positioning signals that exhibit time-incoherence;

b) each of said at least one positioning-unit device further comprises the steps of;

i) generating and transmitting a plurality of frequency-diverse positioning signals;

ii) receiving said plurality of frequency-diverse positioning signals from said at least one reference transmitter, one or more of the at least one positioning-unit devices, or any combination thereof;

iii) independently chronologically synchronizing each frequency-diverse positioning signal from said at least one reference transmitter or said other positioning-unit devices or both to a respective frequency-diverse positioning signal from said positioning-unit device;

such that said time-incoherence is common amongst all frequency-diverse positioning signals;

c) said roving position receiver further comprising the steps of

i) receiving said independently chronologically synchronized frequency diverse positioning signals;

ii) interpreting said common time-incoherence as a receiver clock bias;

such that an accurate position solution is calculated incorporating said receiver clock bias.

3. A method according to claim 1, wherein said roving position receiver'"'"'s calculated position in step (c) is determined by carrier single-point position-velocity-time (PVT) solutions.

4. A method according to claim 1, wherein said received signals in step (c) include a pseudorandom code component and wherein said roving position receiver determines pseudorandom code single-point position solutions derived from said pseudorandom code component within each received signal.

5. A method according to claim 1, wherein said received signals in step (c) include a carrier component and wherein said roving position receiver determines carrier single-point position solutions derived from said carrier component within each received signal.

6. A method according to claim 1, wherein said received signals in step (c) include a data component and wherein said roving position receiver determines data single-point position solutions derived from said date component within each received signal.

7. A method according to claim 1, wherein said roving position receiver'"'"'s calculated position in step (c) determines said at least one reference transmitter'"'"'s timebase by calculating position-velocity-time (PVT) solutions.

8. A method according to claim 1, wherein said roving position receiver'"'"'s calculated position in step (c) determines said at least one reference transmitter'"'"'s timebase by calculating carrier single-point positioning solutions.

9. A method according to claim 1, wherein said received signals in step (c) include a carrier component comprising an initially ambiguous number of carrier cycles component and a fractional cycle component.

10. A method according to claim 9, wherein said roving position receiver'"'"'s calculated position in step (c) of claim 1 is determined by:

a) resolving said initially ambiguous number of carrier cycles component to generate a resolved integer cycle component;

b) summing said resolved integer cycle component with said fractional cycle component to generate a precise carrier phase pseudorange;

c) determining carrier single-point position solutions from said precise carrier phase pseudorange within each received signal;

such that said carrier single-point position solutions can be determined without the need for differential correction.

11. A method according to claim 1, wherein each of said at least one or more reference transmitters includes positioning-unit devices, Wide Area Augmentation System satellites, Global Navigation Satellite System satellites, Pseudolites, or devices that incorporate timing information.

12. A positioning system which enables a roving position receiver to determine its own position, said positioning system comprising:

a) at least one reference transmitter, each of said at least one reference transmitter configured to generate and transmit reference positioning signals according to the timebase of said at least one reference transmitter;

b) at least one positioning-unit device, each of said at least one positioning-unit devices comprising;

i) means for receiving and interpreting signals transmitted by either said at least one reference transmitter or said at least one positioning-unit device or both said at least one reference transmitter and said at least one positioning-unit device;

ii) means for determining a reference positioning signal propagation delay between said at least one reference transmitter and said positioning-unit device;

iii) means for generating and transmitting a unique positioning signal;

iv) means for receiving and interpreting said unique positioning signal;

v) means for comparing said received and interpreted signals from step (i) and said unique positioning signal from step (iv) to deduce a transmission difference;

vi) means for continuously adjusting said generation and transmission of said unique positioning signal according to;

a) said deduced transmission difference from step (v); and

b) said reference positioning signal propagation delay from step (ii);

such that said unique positioning signal is chronologically synchronized to said reference positioning signal;

c) means for said roving position receiver to receive either;

i) said chronologically synchronized unique positioning signals;

or

ii) both said reference positioning signals and said chronologically synchronized unique positioning signals; and

subsequently calculate its own position without the requirement of differential equations.

13. A positioning system according to claim 12, wherein:

a) said at least one reference transmitter is further configured to generate and transmit a plurality of frequency-diverse positioning signals that exhibit time-incoherence;

b) said at least one positioning-unit device further comprises;

i) means for generating and transmitting a plurality of frequency-diverse positioning signals;

ii) means for receiving said plurality of frequency-diverse positioning signals from said at least one reference transmitter, one or more of the at least one positioning-unit devices, or any combination thereof;

iii) means for independently chronologically synchronizing each of the plurality of received frequency-diverse positioning signal, from said at least one reference transmitter, one or more of the at least one positioning-unit devices, or any combination thereof, to a respective frequency-diverse positioning signal from said positioning-unit device;

such that said time-incoherence is common amongst all frequency-diverse positioning signals;

c) said roving position receiver further comprising;

i) means for receiving said independently chronologically synchronized frequency-diverse positioning signals;

ii) means for interpreting said common time-incoherence as a receiver clock bias;

such that an accurate positioning solution is calculated incorporating said receiver clock bias.

14. A positioning system according to claim 12, wherein said roving position receiver'"'"'s calculated position in step (c) is determined by carrier single-point position-velocity-time (PVT) solutions.

15. A positioning system according to claim 12, wherein said received signals in step (c) include a pseudorandom code component and wherein said roving position receiver determines pseudorandom code single-point solutions derived from said pseudorandom code component within each received signal.

16. A positioning system according to claim 12, wherein said received signals in step (c) include a carrier component and wherein said roving position receiver determines carrier single-point position solutions derived from said carrier component within each received signal.

17. A positioning system according to claim 12, wherein said received signals in step (c) include a data component and wherein said roving position receiver determines data single-point solution solutions derived from said data component within each received signal.

18. A positioning system according to claim 12, wherein said roving position receiver'"'"'s calculated position in step (c) determines said at least one reference transmitter'"'"'s timebase by calculating position-velocity-time (PVT) solutions.

19. A positioning system according to claim 12, wherein said roving position receiver'"'"'s calculated position in step (c) determines said at least one reference transmitter'"'"'s timebase by calculating carrier single-point positioning solutions.

20. A positioning system according to claim 12, wherein said received signals in step (c) include a carrier component comprising an initially ambiguous number of carrier cycles component and a fractional cycle component.

21. A positioning system according to claim 20, wherein said roving position receiver'"'"'s calculated position in step (c) of claim 12 is determined by:

a) resolving said initially ambiguous number of carrier cycles component to generate a resolved integer cycle component;

b) summing said resolved integer cycle component with said fractional cycle component to generate a precise carrier phase pseudorange;

c) determining carrier single-point position solutions from said precise carrier phase pseudorange within each received signal;

such that said carrier single-point position solutions can be determined without the need for differential correction.

22. A positioning system according to claim 12, wherein each of said at least one or more reference transmitters includes positioning-unit devices, Wide Area Augmentation System satellites, Global Navigation Satellite System satellites, Pseudolites, or devices that incorporate timing information.

23. A method for determining the position of a roving position receiver in a positioning system comprising at least one reference transmitter, and at least one positioning-unit device, said method comprising the steps of:

a) each of said at least one reference transmitter generating and transmitting reference positioning signals according to the timebase of said at least one reference transmitter, wherein each of said at least one reference transmitters is at a known location;

b) each of said at least one positioning-unit device;

i) receiving and interpreting said at least one reference positioning signal;

ii) generating and transmitting said unique positioning signal, wherein said unique positioning signal is aligned with a frequency steerable clock;

iii) receiving and interpreting said unique positioning signal;

iv) measuring a frequency difference between said received at least one reference positioning (i) and said received unique positioning signal (iii);

v) adjusting the frequency of said frequency steerable clock by an amount derived from said measured frequency difference (iv) and consequently adjusting said unique positioning signal;

vi) determining a reference positioning signal propagation delay between said at least one reference transmitter and said positioning-unit device;

vii) measuring a time difference between said received reference positioning signal (i) and said received unique positioning signal (iii);

viii) offsetting the frequency of said frequency steerable clock for a period of time derived from said time difference measured in step (vii) and said propagation delay measured in step (vi) and consequently adjusting said unique positioning signal;

such that said unique positioning signal is chronologically synchronized to said reference positioning signals;

c) said roving position receiving either;

i) said chronologically synchronized unique positioning signals;

or

ii) both said reference positioning signals and said chronologically synchronized unique positioning signals; and

subsequently calculating its own position without the requirement of differential corrections.

24. A method according to claim 23, wherein:

d) said at least one reference transmitter is further configured to generate and transmit a plurality of frequency-diverse positioning signals that exhibit time-incoherence;

e) each of said at least one positioning-unit devices further comprises the steps of;

i) generating and transmitting a plurality of frequency-diverse positioning signals;

ii) receiving said plurality of frequency-diverse positioning signals from said at least one reference transmitter, one or more of the at least one positioning-unit devices, or any combination thereof;

iii) independently chronologically synchronizing each of the plurality of received frequency-diverse positioning signal, from said at least one reference transmitter, one or more of the at least one positioning-unit devices, or any combination thereof, to a respective frequency-diverse positioning signal from said positioning-unit device;

such that said time-incoherence is common amongst all frequency-diverse positioning signals;

f) said roving position receiver further comprising the steps of;

i) receiving said independently chronologically synchronized frequency-diverse positioning signals;

ii) interpreting said common time-incoherence as a receiver clock bias;

such that an accurate positioning solution is calculated incorporating said receiver clock bias.

25. A method according to claim 23, wherein said roving position receiver'"'"'s calculated position in step (c) is determined by carrier single-point position-velocity-time (PVT) solutions.

26. A method according to claim 23, wherein said received signals in step (c) include a pseudorandom code component and wherein said roving positioning receiver determines pseudorandom code single-point position solutions derived from said pseudorandom code component within each received signal.

27. A method according to claim 23, wherein said received signals in step (c) include a carrier component and wherein said roving position receiver determines carrier single-point position solutions derived from said carrier component within each received signal.

28. A method according to claim 23, wherein said received signals in step (c) include a data component and wherein said roving position receiver determines data single-point position solutions derived from said data component within each received signal.

29. A method according to claim 23, wherein said roving position receiver'"'"'s calculated position in step (c) determines said at least one reference transmitter'"'"'s timebase by calculating position-velocity-time (PVT) solutions.

30. A method according to claim 23, wherein said roving position receiver'"'"'s calculated position in step (c) determines said at least one reference transmitter'"'"'s timebase by calculating carrier single-point positioning solutions.

31. A method according to claim 23, wherein said received signals in step (c) include a carrier component comprising an initially ambiguous number of carrier cycles component and a fractional cycle component.

32. A method according to claim 31, wherein said roving position receiver'"'"'s calculated position in step (c) of claim 23 is determined by:

a) resolving said initially ambiguous number of carrier cycles component to generate a resolved integer cycle component;

b) summing said resolved integer cycle component with said fractional cycle component to generate a precise carrier phase pseudorange;

c) determining carrier single-point position solutions from said precise carrier phase pseudorange within each received signal;

such that said carrier single-point position solutions can be determined without the need for differential correction.

33. A method according to claim 23, wherein each of said at least one or more reference transmitters includes positioning-unit devices, Wide Area Augmentation System satellites, Global Navigation Satellite System satellites, Pseudolites, or devices that incorporate timing information.

39. A positioning system according to claim 31, wherein said received signals in step (c) include a data component and wherein said roving position receiver determines data single-point position solutions derived from said data component within each received signal.

40. A positioning system according to claim 31, wherein said roving position receiver'"'"'s calculated position in step (c) determines said at least one reference transmitter'"'"'s timebase by calculating position-velocity-time (PVT) solutions.

43. A positioning system according to claim 42, wherein said roving position receiver'"'"'s calculated position in step (c) of claim 31 is determined by:

a) resolving said initially ambiguous number of carrier cycles component to generate a resolved integer cycle component;

b) summing said resolved integer cycle component with said fractional cycle component to generate a precise carrier phase pseudorange;

c) determining carrier single-point position solutions from said precise carrier phase pseudorange within each received signal;

such that said carrier single-point position solutions can be determined without the need for differential correction.

34. A positioning system which enables a roving position receiver to determine its own position, said positioning system comprising:

a) at least one reference transmitter, each of said at least one reference transmitter configured to generate and transmit reference positioning signals according to the timebase of said at least one reference transmitter;

b) at least one positioning-unit device, each of said at least one positioning-unit device comprising;

i) means for receiving and interpreting said at least one reference positioning signal;

ii) means for generating and transmitting said unique positioning signal, wherein said unique positioning signal is aligned with a frequency steerable clock;

iii) means for receiving and interpreting said unique positioning signal;

iv) means for measuring a frequency difference between said received at least one reference positioning signal (i) and said received unique positioning signal (iii);

v) means for adjusting the frequency of said frequency steerable clock by an amount derived from said measured frequency of said frequency steerable clock by an amount derived from said measured frequency difference (iv) and consequently adjusting said unique positioning signal;

vi) means for determining a reference positioning signal propagation delay between said at least one reference transmitter and said positioning-unit device;

vii) means for measuring a time difference between said received reference positioning signal (i) and said received unique positioning signal (iii);

viii) means for offsetting said frequency steerable clock by a period of time derived from said time difference measured in step (vii) and said propagation delay measured in step (vi) and consequently adjusting said unique positioning signal;

such that said unique positioning signal is chronologically synchronized to said reference positioning signals;

c) means for said roving position receiver to receive either;

i) said chronologically synchronized unique positioning signals;

or

ii) both said reference positioning signals and said chronologically synchronized unique positioning signals; and

subsequently calculate its own position without the requirement of differential corrections.

35. A positioning system according to claim 34, wherein:

d) said at least one reference transmitter is further configured to generate and transmit a plurality of frequency-diverse positioning signals that exhibit time-incoherence;

e) said at least one positioning-unit device further comprises;

iv) means for generating and transmitting a plurality of frequency-diverse positioning signals;

v) means for receiving said plurality of frequency-diverse positioning signals from said at least one reference transmitter or from other positioning-unit devices including itself or from both;

vi) means for independently chronologically synchronizing each frequency-diverse positioning signal from said at least one reference transmitter or said other positioning-unit devices or both to a respective frequency-diverse positioning signal from said positioning-unit device;

such that said time in-coherence is common amongst all frequency-diverse positioning signals;

f) said roving position receiver further comprising;

iii) means for receiving said independently chronologically synchronized frequency-diverse positioning signals;

iv) means for interpreting said common time-incoherence as a receiver clock bias;

such that an accurate positioning solution is calculated incorporating said receiver clock bias.

36. A positioning system according to claim 34, wherein said roving position receiver'"'"'s calculated positioning in step (c) is determined by carrier single-point position-velocity-time (PVT) solutions.

37. A positioning system according to claim 34, wherein said received signals in step (e) include a pseudorandom code component and wherein said roving position receiver determines pseudorandom code single-point position solutions derived from said pseudorandom code component within each received signal.

38. A positioning system according to claim 34, wherein said received signals in step (c) include a carrier component and wherein said roving position receiver determines carrier single-point position solutions derived from said carrier component within each received signal.

41. A positioning system according to claim 34, wherein said roving position receiver'"'"'s calculated position in step (c) determines said at least one reference transmitter'"'"'s timebase by calculating carrier single-point solutions.

42. A positioning system according to claim 34, wherein said received signals step (c) include a carrier component comprising an initially ambiguous number of carrier cycles component and a fractional cycle component.

44. A positioning system according to claim 34, wherein each of said at least one or more reference transmitters includes positioning-unit devices, Wide Area Augmentation System satellites, Global Navigation Satellite System satellites, Pseudolites, or devices that incorporate timing information.