METHOD AND APPARATUS FOR IMPROVING ACCURACY AND/OR INTEGRITY OF LONG-TERM-ORBIT INFORMATION FOR A GLOBAL-NAVIGATION-SATELLITE SYSTEM

• US 20080125971A1
• Filed: 02/06/2008
• Published: 05/29/2008
• Est. Priority Date: 06/06/2001
• Status: Abandoned Application

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Inventors: Riben, Matthew, van Diggelen, Frank
• Application Number:
  US12/026,915
• Publication Number:
  US 20080125971A1
• Time in Patent Office: Days
• US Class Current: 701/226
• CPC Class Codes: G01S 19/05 providing aiding data
• CPC Class Codes: G01S 19/254 relating to Doppler shift of satellite signals
• 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

A method and apparatus for monitoring a configuration of satellites to maintain integrity of LTO information in a GNSS receiver of a GNSS or other positioning system is described. The method may include obtaining broadcast ephemeris transmitted from at least one satellite of a constellation of satellites; comparing the broadcast ephemeris to long-term-orbit information available to a global-navigation-satellite receiver; and causing the global-navigation-satellite receiver to not use the long-term-orbit information when the long-term-orbit information does not correspond to the broadcast ephemeris.

Claims

1. A method, comprising:

obtaining long-term-orbit information having a first period of validity, wherein the first period of validity is an amount of time greater than a period of validity for ephemeris broadcast from at least one satellite of a constellation of satellites; and

truncating the long-term-orbit information as a function of time so as to form truncated long-term-orbit information having a second period of validity, wherein the second period of validity is shorter than the first period of validity.

2. The method of claim 1, wherein the second period of validity is longer than the period of validity for ephemeris broadcast from at least one satellite of a constellation of satellites.

3. The method of claim 1, further comprising:

computing a position of a global-navigation-satellite-system receiver as a function of the truncated long-term-orbit information.

4. The method of claim 1, wherein the long-term-orbit information comprises at least one first parameter, wherein the truncated long-term-orbit information comprises at least one second parameter, and wherein the at least one second parameter is more accurate than the at least one first parameter.

5. The method of claim 4, wherein the at least one first parameter is a parameter associated with any of an orbit and a clock of a satellite of a constellation of satellites, and wherein the at least one second parameter is parameter associated with any of such orbit and clock.

6. The method of claim 1, wherein truncating the long-term-orbit information comprises truncating from the long-term-orbit information at least one portion of the long-term-orbit information.

7. The method of claim 6, wherein the at least one portion corresponds to a given interval of the first validity period.

8. The method of claim 7, wherein the interval comprises an interval selected from the group consisting of a look-ahead interval, a forward-looking interval, a backward-looking interval and a look-behind interval.

9. The method of claim 7, wherein the interval comprises a first time corresponding to a beginning of the interval and a second time corresponding to an end of the interval, wherein the first time occurs at any of a time prior to, the same time as and a time after a time reference, and wherein the second time occurs after the first time.

10. The method of claim 9, wherein the time reference comprises a time corresponding to any of a current time of day and a time within the first period of validity.

11. The method of claim 1, wherein obtaining the long-term-orbit information comprises obtaining the long-term-orbit information from a global-navigation-satellite-system receiver.

12. A server comprising:

memory adapted to store executable instructions to;

obtain long-term-orbit information having a first period of validity, wherein the first period of validity is an amount of time greater than a period of validity for ephemeris broadcast from at least one satellite of a constellation of satellites; and

truncate the long-term orbit information as a function of time so as to form truncated long-term-orbit information having a second period of validity, wherein the second period of validity is shorter than the first period of validity; and

a processor adapted to obtain the executable instruction from memory, and to execute the executable instructions.

13. The server of claim 12, wherein the second period of validity is longer than the period of validity for ephemeris broadcast from at least one satellite of a constellation of satellites.

14. The server of claim 12, wherein the executable instructions further comprise:

executable instructions to compute a position of a global-navigation-satellite-system receiver as a function of the truncated long-term-orbit information.

15. The server of claim 12, wherein the long-term-orbit information comprises at least one first parameter, wherein the truncated long-term-orbit information comprises at least one second parameter, and wherein the at least one second parameter is more accurate than the at least one first parameter.

16. The server of claim 12, wherein the at least one first parameter is a parameter associated with any of an orbit and a clock of a satellite of a constellation of satellites, and wherein the at least one second parameter is parameter associated with any of such orbit and clock.

17. The server of claim 12, wherein the executable instructions further comprise:

executable instructions to truncate from the long-term-orbit information at least one portion of the long-term-orbit information.

18. The server of claim 17, wherein the at least one portion corresponds to a given interval of the first validity period.

19. The server of claim 18, wherein the interval comprises an interval selected from the group consisting of a look-ahead interval, a forward-looking interval, a backward-looking interval and a look-behind interval.

20. The server of claim 18, wherein the interval comprises a first time corresponding to a beginning of the interval and a second time corresponding to an end of the interval, wherein the first time occurs at any of a time prior to, the same time as and a time after a time reference, and wherein the second time occurs after the first time.

21. The server of claim 20, wherein the time reference comprises a time corresponding to any of a current time of day and a time within the first period of validity.

22. The server of claim 12, wherein the executable instructions further comprise:

executable instructions to obtain the long-term-orbit information from a global-navigation-satellite-system receiver.

23. A tangible computer accessible medium comprising executable instructions, wherein the executable instructions are computer-executable to implement:

obtaining long-term-orbit information having a first period of validity, wherein the first period of validity is an amount of time greater than a period of validity for ephemeris broadcast from at least one satellite of a constellation of satellites; and

truncating the long-term-orbit information as a function of time so as to form truncated long-term-orbit information having a second period of validity, wherein the second period of validity is shorter than the first period of validity.

24. The tangible computer accessible medium of claim 23, wherein the second period of validity is longer than the period of validity for ephemeris broadcast from at least one satellite of a constellation of satellites.

25. The tangible computer accessible medium of claim 23, wherein the executable instructions are computer-executable to further implement:

truncating from the long-term-orbit information at least one portion of the long-term-orbit information, wherein the at least one portion of the long-term-orbit information corresponds to a given interval of the first validity period.