EPHEMERIS EXTENSION METHOD FOR GNSS APPLICATIONS

• US 20120256792A1
• Filed: 09/27/2011
• Published: 10/11/2012
• Est. Priority Date: 04/24/2006
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Garin, Lionel
• Granted Patent: US 9,000,979 B2
• Time in Patent Office: Days
• US Class Current: 342/357.66
• CPC Class Codes: G01S 19/258 relating to the satellite constellation, e.g. almanac, ephemeris data, lists of satellites in view
• CPC Class Codes: G01S 19/27 creating, predicting or correcting ephemeris or almanac data within the receiver

Abstract

Systems, methods and devices for improving the performance of Global Navigation Satellite System (GNSS) receivers are disclosed. In particular, the improvement of the ability to calculate a satellite position or a receiver position where a receiver has degraded ability to receive broadcast ephemeris data directly from a GNSS satellite is disclosed. Correction terms can be applied to an approximate long-term satellite position model such as the broadcast almanac.

Claims

1. A method comprising:

storing in a memory of a receiver, a prediction file comprising satellite position prediction data associated with a plurality of satellites for defining predicted positions of each of the satellites over a plurality of defined time intervals;

defining at least one correction value for each satellite, the at least one correction value being valid for use during at least one of the defined time intervals;

calculating at least one corrected satellite position at said at least one defined time interval by applying the correction data value that is valid for use during said at least one defined time interval to the satellite prediction data associated with said at least one defined time interval; and

estimating a position of the receiver based, at least in part on said at least one corrected satellite location.

2. The method of claim 1, wherein storing in a memory a prediction file further comprises storing in the memory associated with the receiver, at least one correction value associated with each satellite.

3. The method of claim 2, wherein the at least one correction value comprising at least one different correction value for each of the plurality of defined time intervals.

4. The method of claim 1, wherein the at least one correction value comprising at least one different correction value for each of the plurality of defined time intervals.

5. The method of claim 1, wherein said satellite position prediction data comprises almanac data.

6. The method of claim 1, wherein defining at least one correction value for each satellite comprises defining at least one separate correction value for each separate satellite, for each separate one of said time intervals.

7. The method of claim 1, wherein defining at least one correction value for each satellite comprises defining at least one separate correction value for each separate one of said time intervals.

8. The method of claim 1, wherein said at least one of said plurality of defined time intervals is less than one hour.

9. The method of claim 1, wherein said satellite position prediction data for at least one of said plurality of defined time intervals is based, at least in part, on a model comprising Kepler ephemeris parameters.

10. The method of claim 1, wherein said satellite position prediction data comprises Kepler almanac parameters and wherein said at least one correction value comprises a plurality of correction factors associated with the Kepler almanac parameters.

11. The method of claim 10, wherein said correction factors comprise at least one of harmonic correction factors or polynomial correction factors.

12. A method of estimating the position of a receiver, the method comprising:

storing in memory associated with the receiver a prediction file comprising a plurality of almanac correction data sets valid for use during a corresponding plurality of respective, defined time intervals;

calculating at least one corrected satellite position at one of said defined time intervals by applying the correction data stored in the prediction file that is valid for use during said one of said defined time intervals;

estimating a position of the receiver based, at least in part on said at least one corrected satellite location.

13. The method of claim 12, wherein said almanac correction data includes different sets of correction data in at least two of the plurality of defined time intervals.

14. A method comprising operating a processor to create and store a prediction file comprising almanac correction data based, at least in part, on a first prediction of a satellite orbit and a second prediction of said satellite orbit, said almanac correction data being valid for use during a period of time comprising a plurality of defined time intervals, wherein at least a portion of said almanac correction data is compacted in size based, at least in part, on said plurality of defined time intervals.

15. The method of claim 14, wherein the almanac correction data comprising at least one different correction value for each of the plurality of defined time intervals.

16. The method of claim 14, wherein said almanac correction data comprises at least one of coordinate correction data or coordinate derivative correction data associated with said at least one of said plurality of defined time intervals.

17. The method of claim 14, wherein said almanac correction data for at least one of said plurality of defined time intervals is based, at least in part, on a model comprising Kepler ephemeris parameters.

18. The method of claim 17, wherein said at least one of said plurality of defined time intervals is greater than one hour.

19. The method of claim 14, wherein said almanac correction data comprises Kepler almanac parameters and correction factors.

20. The method of claim 19, wherein said correction factors comprise at least one of harmonic correction factors or polynomial correction factors.

21. A GNSS receiver comprising:

a memory storing a prediction file comprising satellite position prediction data associated with a plurality of satellites for defining predicted positions of each of the satellites over a plurality of defined time intervals;

a processor defining at least one correction value for each satellite, the at least one correction value being valid for use during at least one of the defined time intervals;

the processor further calculating at least one corrected satellite position at said at least one defined time interval by applying the correction data value that is valid for use during said at least one defined time interval to the satellite prediction data associated with said at least one defined time interval; and

the processor further estimating a position of the receiver based, at least in part on said at least one corrected satellite location.

22. The receiver of claim 21, wherein the at least one correction value comprising at least one different correction value for each different one of the plurality of defined time intervals.

23. The receiver of claim 21, wherein the at least one correction value comprising at least one different correction value for each different one of the plurality of satellites.

24. The receiver of claim 23, wherein the at least one correction value comprising at least one different correction value for each different one of the plurality of defined time intervals.

25. The receiver of claim 21, wherein said satellite position prediction data comprises almanac data.

26. The receiver of claim 21, wherein the processor defines at least one separate correction value for each separate satellite, for each separate one of said time intervals.

27. The receiver of claim 21, wherein said satellite position prediction data for at least one of said plurality of defined time intervals is based, at least in part, on a model comprising Kepler ephemeris parameters.

28. The receiver of claim 27, wherein said correction factors comprise at least one of harmonic correction factors or polynomial correction factors.

29. The receiver of claim 21, wherein said satellite position prediction data comprises Kepler almanac parameters and wherein said at least one correction value comprises a plurality of correction factors associated with the Kepler almanac parameters.

30. A device comprising:

a memory;

at least one processor to;

obtain a prediction file comprising satellite position prediction data associated with a plurality of satellites for defining predicted positions of each of the satellites over a plurality of defined time intervals;

obtain at least one correction value for each satellite, the at least one correction value being valid for use during at least one of the defined time intervals;

calculate at least one corrected satellite position at said at least one defined time interval by applying the correction data value that is valid for use during said at least one defined time interval to the satellite prediction data associated with said at least one defined time interval; and

estimate a position of the receiver based, at least in part on said at least one corrected satellite location.

31. The device of claim 30, wherein the at least one correction value comprising at least one different correction value for each of the plurality of defined time intervals.

32. An article comprising:

a computer readable medium having computer code stored therein that is implementable by a processor of a receiver to;

obtain a prediction file comprising satellite position prediction data associated with a plurality of satellites for defining predicted positions of each of the satellites over a plurality of defined time intervals;

obtain at least one correction value for each satellite, the at least one correction value being valid for use during at least one of the defined time intervals;

calculate at least one corrected satellite position at said at least one defined time interval by applying the correction data value that is valid for use during said at least one defined time interval to the satellite prediction data associated with said at least one defined time interval; and

estimate a position of the receiver based, at least in part on said at least one corrected satellite location.

33. A device comprising:

memory means in a receiver for storing a prediction file comprising satellite position prediction data associated with a plurality of satellites for defining predicted positions of each of the satellites over a plurality of defined time intervals;

processing means for defining at least one correction value for each satellite, the at least one correction value being valid for use during at least one of the defined time intervals;

processing means for calculating at least one corrected satellite position at said at least one defined time interval by applying the correction data value that is valid for use during said at least one defined time interval to the satellite prediction data associated with said at least one defined time interval; and

processing means for estimating a position of the receiver based, at least in part on said at least one corrected satellite location.

34. The apparatus of claim 33, wherein the at least one correction value comprising at least one different correction value for each different one of the plurality of defined time intervals.

35. The apparatus of claim 33, wherein the at least one correction value comprising at least one different correction value for each different one of the plurality of satellites.

36. The apparatus of claim 33, wherein the processing means comprises means for defining at least one separate correction value for each separate satellite, for each separate one of said time intervals.

37. The apparatus of claim 33, wherein said satellite position prediction data for at least one of said plurality of defined time intervals is based, at least in part, on a model comprising Kepler ephemeris parameters.

38. The apparatus of claim 37, wherein said correction factors comprise at least one of harmonic correction factors or polynomial correction factors.

39. A receiver comprising:

at least one memory storing a prediction file comprising a plurality of almanac correction data sets valid for use during a corresponding plurality of respective, defined time intervals;

at least one processor to calculate at least one corrected satellite position at one of said defined time intervals by applying the correction data stored in the prediction file that is valid for use during said one of said defined time intervals;

the at least one processor to estimate a position of the receiver based, at least in part on said at least one corrected satellite location.

40. The receiver of claim 39, wherein said almanac correction data includes different sets of correction data in at least two of the plurality of defined time intervals.

41. An article comprising:

a computer readable medium having computer code stored therein that is implementable by a processor of a receiver to;

obtain from at least one memory of a receiver, contents of a prediction file comprising a plurality of almanac correction data sets valid for use during a corresponding plurality of respective, defined time intervals;

calculate at least one corrected satellite position at one of said defined time intervals by applying the correction data stored in the prediction file that is valid for use during said one of said defined time intervals; and

estimate a position of the receiver based, at least in part on said at least one corrected satellite location.

42. The article of claim 41, wherein said almanac correction data includes different sets of correction data in at least two of the plurality of defined time intervals.

43. A device comprising:

memory means in a receiver for storing a prediction file comprising a plurality of almanac correction data sets valid for use during a corresponding plurality of respective, defined time intervals;

processing means for calculating at least one corrected satellite position at one of said defined time intervals by applying the correction data stored in the prediction file that is valid for use during said one of said defined time intervals;

processing means for estimating a position of the receiver based, at least in part on said at least one corrected satellite location.

44. The device of claim 43, wherein said almanac correction data includes different sets of correction data in at least two of the plurality of defined time intervals.

45. A receiver comprising a processor configured to create and store a prediction file comprising almanac correction data based, at least in part, on a first prediction of a satellite orbit and a second prediction of said satellite orbit, said almanac correction data being valid for use during a period of time comprising a plurality of defined time intervals, wherein at least a portion of said almanac correction data is compacted in size based, at least in part, on said plurality of defined time intervals.

46. The receiver of claim 45, wherein the almanac correction data comprising at least one different correction value for each of the plurality of defined time intervals.

47. The receiver of claim 46, wherein said almanac correction data comprises at least one of coordinate correction data or coordinate derivative correction data associated with said at least one of said plurality of defined time intervals.

48. The receiver of claim 46, wherein said almanac correction data for at least one of said plurality of defined time intervals is based, at least in part, on a model comprising Kepler ephemeris parameters.

49. The receiver of claim 48, wherein said at least one of said plurality of defined time intervals is greater than one hour.

50. An article comprising:

a computer readable medium having computer code stored therein that is implementable by a processor of a receiver to create and store a prediction file comprising almanac correction data based, at least in part, on a first prediction of a satellite orbit and a second prediction of said satellite orbit, said almanac correction data being valid for use during a period of time comprising a plurality of defined time intervals, wherein at least a portion of said almanac correction data is compacted in size based, at least in part, on said plurality of defined time intervals.