Navigation satellite acquisition in satellite positioning system receiver

• US 7,250,904 B2
• Filed: 10/08/2004
• Issued: 07/31/2007
• Est. Priority Date: 10/08/2004
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Strother, Troy L., King, Thomas Michael, Chang, Alan
• Primary Examiner(s): Tarcza; Thomas H.
• Assistant Examiner(s): Chen; Shelley
• Application Number:
  US10/961,322
• Publication Number:
  US 20060077096A1
• Time in Patent Office: 1,026 Days
• Field of Search: 342/357.01, 34235706-35715, 342/352, 701213-214
• US Class Current: 342/357.67
• CPC Class Codes: G01S 19/28 Satellite selection

Abstract

A method in a mobile satellite positioning system receiver operating in cold-start mode, including searching for and detecting (310) a first satellite in a constellation of orbiting satellites, searching (320) for a second satellite based on detection probability information for non-detected satellites, the detection probability information obtained using information about one of satellites not detected or the first satellite detected. In one embodiment, the detection probability information is based on a measure of range between the non-detected satellites and the first satellite detected, and in another embodiment the detection probability information is based on a measure of angle between the non-detected satellites and the first satellite detected.

Claims

1. A method in a satellite positioning system receiver, the method comprising:

detecting a first satellite in a constellation of satellites;

determining range information including range variance between non-detected satellites and the first detected satellite,

searching for a subsequent satellite using the range information.

2. The method of claim 1,

detecting a second satellite in the constellation of satellites using range information,

determining new range information based on ranges from non-detected satellites to a combined position of the first and second satellites detected.

3. The method of claim 2,

detecting a third satellite in the constellation of satellites using the new range information,

determining subsequent range information based on ranges from remaining non-detected satellites to a combined position of the first, second and third satellites detected.

4. The method claim 1,

determining range information includes determining an average range between each of the non-detected satellites and the first detected satellite,

searching for the subsequent satellite based on the average ranges.

5. The method of claim 4, determining the average range between each of the non-detected satellites and the first detected satellite based on at least one period over which range between satellites repeats.

6. The method of claim 1,

detecting the first satellite by searching for satellites in the satellite positioning system,

searching for the subsequent satellite based on the range information for only satellites not searched before detecting the first satellite.

7. The method of claim 1,

detecting the first satellite by searching for satellites in a satellite constellation,

excluding satellites searched before detecting the first satellite when searching for the subsequent satellite based on the range information.

8. The method of claim 1,

detecting the first satellite by searching a constellation of satellites,

prioritizing the search for the first satellite based on which satellites of the constellation are most visible within a specified range of latitudes.

9. The method of claim 1,

detecting the first satellite by searching a constellation of satellites,

prioritizing the search for the first satellite based on a duration of visibility of the satellites located within the specified range of latitudes.

10. A method in a satellite positioning system receiver, the method comprising:

prioritizing a satellite search order for a satellite in a constellation of orbiting satellites based on a randomized Monte-Carlo simulation that randomly selects and tests search orders over a geographic region and over the constellation orbit period;

searching for the satellite in the constellation based upon the prioritized search order.

11. The method of claim 10, prioritizing the search order for the satellite in the constellation based on a duration of visibility of satellites within a specified range of latitudes.

12. The method of claim 10,

detecting a first satellite,

determining probability detection information for non-detected satellites in the constellation,

re-prioritizing the satellite search order based on the probability detection information,

searching for another satellite in the constellation based upon the re-prioritized search order.

13. The method of claim 10, searching for the satellite in the constellation based upon the prioritized search order includes searching for a first satellite in a cold-start mode of operation of the satellite positioning system receiver.

14. A method in a mobile satellite positioning system receiver, the method comprising:

searching for a satellite in a constellation of orbiting satellites;

detecting a first satellite,

determining an initial satellite search order for the first satellite based on whether the mobile satellite positioning system receiver is on land or water;

searching for a second satellite based on detection probability information for non-detected satellites,

the detection probability information obtained using information about one of satellites not detected or the first satellite detected.

15. The method of claim 14, obtaining the detection probability information for the non-detected satellites based on a measure of range between the non-detected satellites and the first satellite detected.

16. The method of claim 15,

detecting a second satellite in the constellation of orbiting satellites,

searching for a third satellite based on new detection probability information for non-detected satellites,

obtaining the new detection probability information for the non-detected satellites based on based on a measure of range between the non-detected satellites and a combination of the first and second satellites detected.

17. The method of claim 14, determining the detection probability information based on a measure of angle between the non-detected satellites and the first satellite detected.

18. The method of claim 14,

determining an initial satellite search order for the first satellite based on which satellites are more most visible within a specified range of latitudes.

19. The method of claim 14, determining an initial satellite search order for the first satellite based on a duration of visibility of the satellites.

20. The method of claim 14,

detecting the first satellite in cold-start mode,

searching for a second satellite based on detection probability information for non-detected satellites in cold-start mode.

21. A method in a satellite positioning system receiver, the method comprising:

detecting a first satellite in a constellation of satellites;

searching for a subsequent satellite using range information based on ranges from non-detected satellites to the detected satellite,

determining range information includes determining maximum and minimum range between each of the non-detected satellites and the first detected satellite,

searching for a subsequent satellite based on the maximum and minimum range.