Method and system for location-dependent time-specific correction data

• US 8,134,497 B2
• Filed: 09/30/2008
• Issued: 03/13/2012
• Est. Priority Date: 09/30/2008
• Status: Active Grant

• Current Assignee: Trimble Navigation Limited (Trimble Inc.)
• Original Assignee: Trimble Navigation Limited (Trimble Inc.)
• Inventors: Janky, James M., Vollath, Ulrich, Talbot, Nicholas C.
• Primary Examiner(s): Tarcza, Thomas
• Assistant Examiner(s): MCGUE, FRANK J
• Application Number:
  US12/241,451
• Publication Number:
  US 20100079333A1
• Time in Patent Office: 1,260 Days
• Field of Search: 342/357.03, 342/357.24, 342/357.42, 342/357.44
• US Class Current: 342/357.24
• 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 19/43 using carrier phase measurements, e.g. kinematic positioning; using long or short baseline interferometry

Abstract

A method and system for delivery of location-dependent time-specific corrections. In one embodiment, a first extended-lifetime correction for a first region is generated. A distribution timetable is used to determine a first time interval for transmitting the first extended-lifetime correction to the first region. The first extended-lifetime correction is then transmitted via a wireless communication network to said first region in accordance with said distribution timetable.

Claims

1. A method for delivery of location-dependent time-specific corrections, said method comprising:

generating a first extended-lifetime correction for a first region, wherein said first extended-lifetime correction comprises a virtual reference station correction plus error data descriptive of a plurality of positioning signals, wherein said error data is useable to extrapolate future corrections;

using a distribution timetable to determine a first time for transmitting said first extended-lifetime correction to said first region and to determine a first time interval on which to transmit successive extended-lifetime corrections for said first region to said first region; and

transmitting said first extended-lifetime correction via a wireless communication network to said first region in accordance with said distribution timetable.

2. The method as recited in claim 1 wherein said generating said first extended-lifetime correction further comprises:

generating a first instance of correction data for a location in said first region at a first instance in time and wherein said first instance of correction data is applied to a first geographic position to determine a first corrected geographic position in said first region at said first instance in time;

generating a first instance of error data descriptive of a plurality of positioning signals at said first instance of time and wherein said a first instance of error data is used to determine a second corrected geographic position in said first region at a second instance in time based upon said first instance of correction data and a second instance of data from said plurality of positioning signals; and

conveying said first instance of correction data and said first instance of error data as said extended-lifetime correction.

3. The method as recited in claim 2 further comprising:

conveying error data descriptive of said plurality of positioning signals selected from the group consisting of;

a quantification of satellite clock error for the first instance in time, a quantification of atmosphere induced error for the first instance in time, and a quantification of satellite orbit error for the first instance in time.

4. The method as recited in claim 1 further comprising:

associating said first region with at least one defined time for transmitting said first extended-lifetime correction.

5. The method as recited in claim 4 further comprising:

generating a second extended-lifetime correction for a second region;

accessing said distribution timetable which specifies a second time for transmitting said second extended-lifetime correction to said second region a second time interval on which to transmit successive extended-lifetime corrections for said second region to said second region; and

transmitting said second extended-lifetime correction to said second region via said wireless communication network.

6. The method as recited in claim 5 further comprising:

selecting said wireless communication network from the group consisting of;

a geosynchronous satellite communication network, a Low Earth Orbit/Medium Earth Orbit (LEO/MEO) satellite communication network, a cellular telephone communication network, a pager frequency wireless communication network, a terrestrial radio broadcast network, and a wireless Internet server network.

7. The method as recited in claim 6 further comprising:

accessing said distribution timetable to determine which of a plurality of wireless communication networks is to be used to convey said first extended-lifetime correction to said first region.

8. The method as recited in claim 5 further comprising:

storing a copy of said distribution timetable on a rover station; and

using said stored copy of said distribution timetable to cause a rover station in said first region to use said first extended-lifetime correction received for a period after receipt and until receipt of a successive extended-lifetime correction for said first region to derive a first corrected geographic position.

9. The method as recited in claim 8 further comprising:

adding a third region to said distribution timetable; and

generating a message via said wireless communication network which is configured to cause said rover station to update said stored copy of said distribution timetable.

10. The method as recited in claim 1 further comprising:

selecting said first region;

receiving positioning satellite signal data from at least one Global Navigation Satellite System (GNSS) reference station which is associated with said first region; and

using the positioning satellite signal data from said at least one GNSS reference station to derive said first extended-lifetime correction.

11. A method for delivery of location-dependent time-specific corrections, said method comprising:

storing a copy of a distribution timetable within a rover station in a first region;

said rover station using said distribution timetable to determine a time for receiving a correction which is intended for said first region and a time interval for which said correction is configured to be usable for, wherein said time interval comprises a period greater than one second, wherein said correction comprises a virtual reference station correction plus error data descriptive of a plurality of positioning signals, wherein said error data is useable to extrapolate future corrections for greater than one second; and

said rover station using said correction to determine a first corrected geographic position in said first region.

12. The method as recited in claim 11 further comprising:

using said error data as an extended-lifetime correction configured to be used for a period greater than one second when determining said corrected geographic position.

13. The method as recited in claim 12 wherein said using said extended-lifetime correction further comprises:

said rover station using a first instance of correction data for said first region at a first instance in time to determine said corrected geographic position in said first region at said first instance in time; and

said rover station using a first instance of said error data to determine a second corrected geographic position in said first region at a second instance in time.

14. The method as recited in claim 13 wherein determining said second corrected geographic position further comprises:

determining said second corrected geographic position in said first region using a plurality of positioning signals received by said rover station at a second instance in time, said first instance of correction data, and said first instance of error data.

15. The method as recited in claim 13 said using said first instance of error data further comprises:

using error data descriptive of said plurality of positioning signals selected from the group consisting of a quantification of satellite clock error for the first instance in time, a quantification of atmosphere induced error for the first instance in time, and a quantification of satellite orbit error for the first instance in time.

16. The method as recited in claim 12 further comprising:

receiving said extended-lifetime correction via a wireless communication network.

17. The method as recited in claim 16 further comprising:

utilizing a wireless communication network selected from the group consisting of;

a geosynchronous satellite communication network, a Low Earth Orbit/Medium Earth Orbit (LEO/MEO) satellite communication network, a cellular telephone communication network, a pager frequency wireless communication network, a terrestrial radio broadcast network, and a wireless Internet server network.

18. The method as recited in claim 11 further comprising:

said rover station determining a first geographic position based upon a plurality of received positioning satellite signals,

said rover station determining that said first geographic position is assigned to said first region; and

said rover station using said distribution timetable to determine said time and said time interval.

19. A rover station for determining a position, said rover station comprising:

a positioning signal receiver configured to receive positioning signals from each of a plurality of positioning satellites;

at least one wireless communication device configured to receive an extended-lifetime correction intended for a region to which said rover station is proximate via a wireless communication network, wherein said extended-lifetime correction comprises a virtual reference station correction plus error data descriptive of a plurality of positioning signals, wherein said error data is useable to extrapolate future corrections; and

a processor configured to access a distribution timetable which defines a time for receiving said extended-lifetime correction which is intended for said region and further defines a time interval on which to receive successive extended-lifetime corrections intended for said region.

20. The rover station of claim 19 further comprising:

a positioning unit configured to determine a first position of said rover station for a first instance in time based on the positioning signals for the first instance in time and is configured to determine a corrected geographic position based upon said positioning signals and said extended-lifetime correction.

21. The rover station of claim 20 wherein said positioning unit is further configured to determine a second position of said rover station for a second instance in time based upon received positioning signals for the second instance in time and said extended-lifetime correction.

22. The rover station of claim 20 wherein said positioning unit is configured to derive a correction to the positioning signals for the first instance in time from said extended-lifetime correction and to derive said error data descriptive of said positioning signals for the first instance in time from said extended-lifetime correction.

23. The rover station of claim 22 wherein said positioning unit is configured to derive said error data descriptive of said positioning signals for the first instance in time selected from the group consisting of a quantification of satellite clock error for the first instance in time, a quantification of atmosphere induced error for the first instance in time, and a quantification of satellite orbit error for the first instance in time.

24. The rover station of claim 20 wherein said positioning unit is further configured to:

determine said region in which said rover station is disposed based upon said first position of said rover station for said first instance in time;

access a distribution timetable which specifies said time for receiving said extended-lifetime correction based upon said region; and

receive said extended-lifetime correction at said defined time via a wireless communication network.

25. The rover station of claim 24 wherein said positioning unit is further configured to determine a corrected position based upon said received positioning signals for the first instance in time and said extended-lifetime correction.

26. The rover station of claim 25 wherein said rover station is configured to update said distribution timetable based upon an update message from a master reference station.

27. A system for delivery of location-dependent time-specific corrections comprising:

a master reference station comprising;

a distribution timetable controller input system for selectively accessing a distribution timetable and identifying a region for delivery of an extended-lifetime correction at a defined time and for delivery of successive extended-lifetime corrections for said region on a defined time interval;

a corrections region selection system configured to identify at least one Global Navigation Satellite System (GNSS) reference station which is associated with said region;

a corrections processor configured to access data from said at least one GNSS reference station and to generate said virtual reference station correction for said region for a first instance in time based upon positioning signals from each of a plurality of positioning satellites;

an error generator configured to generate an instance of error data descriptive of said positioning signals for the first instance in time; and

a communicative coupling with a wireless communication network; and

a rover station configured to determine a first geographic position based upon the positioning signals from each of the plurality of positioning satellites and to receive said extended-lifetime correction via said wireless communication network, wherein said extended-lifetime correction comprises said virtual reference station correction and said instance of error data, wherein said error data is useable to extrapolate future corrections.

28. The system of claim 27 wherein said instance of error data is selected from the group consisting of a quantification of satellite clock error for the first instance in time, a quantification of atmosphere induced error for the first instance in time, and a quantification of satellite orbit error for the first instance in time.

29. The system of claim 27 wherein said rover station is further configured to:

determine that said rover station is located in said first region at the instance in time;

access a copy of said distribution timetable which specifies said defined time for receiving said extended-lifetime correction based upon said rover station being located in said region; and

utilizing said extended-lifetime correction received at said defined time to generate a corrected position of said rover station until receipt of a successive extended-lifetime correction.

30. The system of claim 29 wherein said rover station is configured to determine said corrected position based upon said received positioning signals for the first instance in time and said extended-lifetime correction.

31. The system of claim 29 wherein said rover station is configured to determine a second position in said region based upon said correction for the first instance in time, received positioning signals for a second instance of time, and said instance of error data conveyed in said extended-lifetime correction.

32. The system of claim 27 wherein said extended-lifetime correction is conveyed to said rover station using a pathway wireless communication network selected from the group consisting of:

a geosynchronous satellite communication network, a Low Earth Orbit/Medium Earth Orbit (LEO/MEO) satellite communication network, a cellular telephone communication network, a pager frequency wireless communication network, a terrestrial radio broadcast network, and a wireless Internet server network.

33. The system of claim 27 further comprising a second master reference station configured to convey a second extended-lifetime correction for said region for a second defined time and to convey successive extended-lifetime corrections for said region at a second defined time interval.

34. The system of claim 27 further comprising:

a communications path controller configured to access said distribution timetable and to initiate selectively coupling said master reference station with said wireless communication network based upon identifying said region to which said extended-lifetime correction is to be sent.

35. The system of claim 27 further comprising a communications network master controller for selectively coupling a plurality of said master reference stations with said wireless communication network.