METHODS AND SYSTEMS FOR DETERMINING LOCATION USING A HYBRID SATELLITE AND WLAN POSITIONING SYSTEM BY SELECTING THE BEST SPS MEASUREMENTS

• US 20110012784A1
• Filed: 07/16/2009
• Published: 01/20/2011
• Est. Priority Date: 07/16/2009
• Status: Active Grant

• Current Assignee: Skyhook Wireless Incorporated (Liberty Broadband Corp.)
• Original Assignee: Skyhook Wireless Incorporated (Liberty Broadband Corp.)
• Inventors: ALIZADEH-SHABDIZ, Farshid
• Granted Patent: US 8,063,820 B2
• Time in Patent Office: Days
• US Class Current: 342/357.28
• CPC Class Codes: G01S 19/46 the supplementary measurement being of a radio-wave signal type

Abstract

The disclosed subject matter generally relates to hybrid positioning systems and methods, more specifically, systems and methods of integrating a wireless local area network (WLAN) based positioning system (WLAN-PS) and a satellite positioning system (SPS) to improve accuracy of location estimates by selecting the best set of measurements from both systems.

Claims

1. A method of measuring the location of a device in a hybrid positioning system using satellite and WLAN positioning information, the method comprising:

determining a WLAN based location estimate for a WLAN and satellite enabled device based on one or more WLAN access points;

obtaining satellite measurements for the WLAN and satellite enabled device from at least three different satellites;

selecting the satellite measurements which are consistent with the WLAN based location estimate; and

determining a final location estimate using the WLAN access points and the selected set of satellite measurements.

2. The method of claim 1, wherein consistent with the WLAN based location estimate comprises a satellite measurement that is within the expected error of the WLAN access points location estimate.

3. The method of claim 1, wherein consistent with the WLAN based location estimate comprises a satellite measurement that is within 100 meters of the WLAN based location estimate.

4. The method of claim 1, wherein the step of selecting the satellite measurements which are consistent with the WLAN based location estimate comprises:

eliminating satellite measurements which are not consistent with the WLAN based location estimate.

5. The method of claim 1, wherein the satellite measurements comprise a cluster.

8. The method of claim 1, wherein the satellite measurements provide a satellite based location solution in the form of a region, a surface, or a curve.

9. The method of claim 1, comprising selecting satellite measurements having a small distance to the WLAN based location estimate.

10. The method of claim 9, wherein the small distance is on the order of ten meters.

11. The method of claim 1 comprising eliminating satellite measurements having a large distance to the WLAN based location estimate.

12. The method of claim 11, wherein the large distance is on the order of one hundred meters.

13. The method of claim 1, wherein the satellite measurements comprise satellite position data, satellite velocity data, psuedorange measurement, Doppler frequency measurement, and time of signal transmission.

6. The method of claim 6, wherein each cluster of satellite measurements provides a satellite based location estimate or set of possible locations for the mobile device.

7. The method of claim 7 comprising selecting the satellite based location estimate or set of possible locations that is closest to the WLAN based location estimate.

14. A mobile device having a hybrid positioning system for increasing the accuracy of a WLAN based position estimate using satellite positioning information, the mobile device comprising:

a hybrid positioning module comprising;

a WLAN module for receiving information from one or more WLAN access points and determining a WLAN based location estimate;

a satellite positioning module for obtaining satellite measurements from at least three different satellites; and

logic located in the hybrid positioning module for selecting the satellite measurements which are consistent with the WLAN based location estimate and for determining a final location estimate using the WLAN access points and the selected set of satellite measurements.

15. A method of measuring the location of a device in a hybrid positioning system using satellite and WLAN positioning information, the method comprising:

determining a WLAN based location estimate for a WLAN and satellite enabled device based on one or more WLAN access points;

obtaining satellite measurements for the WLAN and satellite enabled device from at least five different satellites;

determining a plurality of satellite based location estimates using sets of at least four satellite measurements selected from the at least five different satellites;

selecting the satellite based location estimate that is consistent with the WLAN based location estimate; and

determining a final location estimate using the WLAN access points and the set of satellites that provided the selected satellite based location estimate.

16. The method of claim 15, wherein consistent with the WLAN based location estimate comprises a satellite based location estimate that is within the expected error of the WLAN based location estimate.

17. The method of claim 15, wherein consistent with the WLAN based location estimate comprises a satellite location estimate that is within 100 meters of the WLAN based location estimate.

18. The method of claim 16, wherein the step of selecting the satellite based location estimates that are consistent with the WLAN based location estimate comprises:

eliminating satellite based location estimates that are not consistent with the WLAN based location estimate.

19. The method of claim 15, wherein the satellite measurements comprise a cluster.

20. The method of claim 19, wherein each cluster of satellite measurements provides a different satellite based location estimate for the mobile device.

21. The method of claim 20 comprising selecting the satellite based location estimate that is closest to the WLAN based location estimate.

22. The method of claim 15, comprising selecting a satellite based location having a small distance to the WLAN based location estimate.

23. The method of claim 22, wherein the small distance is on the order of ten meters.

24. The method of claim 15 comprising eliminating satellite based location estimates having a large distance to the WLAN based location estimate.

25. The method of claim 24, wherein the large distance is on the order of one hundred meters.

26. A system for measuring the location of a device in a hybrid positioning system using satellite and WLAN positioning information, the system comprising:

a hybrid positioning module comprising;

a WLAN module for receiving information from one or more WLAN access points and determining a WLAN based location estimate;

a satellite positioning module for obtaining satellite measurements from at least five different satellites; and

logic located in the hybrid positioning module configured to determine a plurality of satellite based location estimate using sets of at least four satellites selected from the at least five different satellites, select the satellite based location estimate that is consistent with the WLAN based location estimate and determine a final location estimate using the WLAN access points and the set of satellites that provided the selected satellite based location estimate.