Determination of a relative position of a satellite signal receiver

• US 20080272961A1
• Filed: 05/01/2007
• Published: 11/06/2008
• Est. Priority Date: 05/01/2007
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Wirola, Lauri, Syrjarinne, Jari
• Granted Patent: US 7,869,811 B2
• Time in Patent Office: Days
• US Class Current: 342/357.12
• CPC Class Codes: G01S 19/55 Carrier phase ambiguity resolution; Floating ambiguity; LAMBDA [Least-squares AMBiguity Decorrelation Adjustment] method

Abstract

For enhancing the quality of a relative positioning, a filter is adjusted depending on information on a movement of a satellite signal receiver. A position of the satellite signal receiver is determined relative to a reference station using the filter, wherein measurements on satellite signals received by the satellite signal receiver and measurements on satellite signals provided for the reference station are used as input to the filter. The measurements for the reference station may be received in messages which are assembled and provided for transmission and which may include in addition an indication of a current movement of the reference station.

Claims

1. A method comprising:

adjusting a filter depending on information on a movement of a satellite signal receiver; and

determining a position of the satellite signal receiver relative to a reference station using the filter, wherein measurements on satellite signals received by the satellite signal receiver and measurements on satellite signals provided for the reference station are used as input to the filter.

2. The method according to claim 1, wherein the filter is adjusted to have a state space including rate of change components only in case the information on a movement of the satellite signal receiver indicates a change of the position of the satellite signal receiver relative to the reference station.

3. The method according to claim 1, wherein the filter is adjusted to have a state space including acceleration components only in case the information on a movement of the satellite signal receiver indicates a change of the position of the satellite signal receiver relative to the reference station.

4. The method according to claim 1, wherein the filter is adjusted by using a lower process noise in case the information on a movement of the satellite signal receiver indicates no change of the position of the satellite signal receiver relative to the reference station and a higher process noise in case the information on a movement of the satellite signal receiver indicates a change of the position of the satellite signal receiver relative to the reference station.

5. The method according to claim 1, wherein the filter is adjusted by using a process noise having a magnitude which depends on a change of motion of the satellite signal receiver relative to the reference station.

6. The method according to claim 1, wherein the filter is adjusted by using a process noise which increases with an increasing change of motion of the satellite signal receiver relative to the reference station.

7. The method according to claim 1, wherein adjusting the filter depending on information on a movement of a satellite signal receiver comprises adjusting the filter depending on a change of a position of the satellite signal receiver relative to the reference station, and wherein the reference station is assumed to be located at a fixed position.

8. The method according to claim 1, wherein adjusting the filter depending on information on a movement of a satellite signal receiver comprises adjusting the filter depending on a change of a position of the satellite signal receiver relative to the reference station, and wherein information on a movement of the reference station is provided.

9. The method according to claim 1, wherein the filter is a Kalman filter.

10. The method according to claim 1, wherein the measurements are used by the filter for forming at least one of double difference observables, single difference observables and wide-lane observables.

11. The method according to claim 1, wherein the measurements comprise carrier-phase measurements on satellite signals.

25. A computer program product in which program code is stored in a computer readable medium the program code realizing the method of claim 1 when executed in a processor.

12. An apparatus comprising:

a filter adjustment component configured to adjust a filter depending on information on a movement of a satellite signal receiver; and

a positioning component configured to determine a position of the satellite signal receiver relative to a reference station using the filter, wherein measurements on satellite signals received by the satellite signal receiver and measurements on satellite signals provided for the reference station are used as input to the filter.

13. The apparatus according to claim 12, wherein the filter adjustment component is configured to adjust the filter to have a state space including rate of change components only in case the information on a movement of the satellite signal receiver indicates a change of the position of the satellite signal receiver relative to the reference station.

14. The apparatus according to claim 12, wherein the filter adjustment component is configured to adjust the filter to have a state space including acceleration components only in case the information on a movement of the satellite signal receiver indicates a change of the position of the satellite signal receiver relative to the reference station.

15. The apparatus according to claim 12, wherein the filter adjustment component is configured to adjust the filter by using a lower process noise assumption in case the information on a movement of the satellite signal receiver indicates no change of the position of the satellite signal receiver relative to the reference station and a higher process noise assumption in case the information on a movement of the satellite signal receiver indicates a change of the position of the satellite signal receiver relative to the reference station.

16. The apparatus according to claim 12, wherein the filter adjustment component is configured to adjust the filter by using a process noise assumption having a magnitude which depends on a change of motion of the satellite signal receiver relative to the reference station indicated by the information on a movement of the satellite signal receiver.

17. The apparatus according to claim 12, wherein the filter adjustment component is configured to adjust the filter by using a process noise assumption which increases with an increasing change of motion of the satellite signal receiver relative to the reference station indicated by the information on a movement of the satellite signal receiver.

18. The apparatus according to claim 12, wherein adjusting the filter depending on information on a movement of a satellite signal receiver comprises adjusting the filter depending on a change of a position of the satellite signal receiver relative to the reference station, and wherein the reference station is assumed to be located at a fixed position.

19. The apparatus according to claim 12, wherein the filter adjustment component is further configured to receive information on a movement of the reference station and to adjust the filter depending on a change of a position of the satellite signal receiver relative to the reference station.

20. The apparatus according to claim 12, wherein the filter is a Kalman filter.

21. The apparatus according to claim 12, wherein the filter is designed to use the measurements for forming at least one of double difference observables, single difference observables and wide-lane observables.

22. The apparatus according to claim 12, wherein the measurements comprise carrier-phase measurements on satellite signals.

23. A device comprising:

an apparatus according to claim 12; and

a wireless communication component configured to receive from another device measurements on satellite signals for the reference station.

24. The device of claim 23, further comprising the satellite signal receiver.

35. A system comprising:

an apparatus according to claim 12; and

an apparatus comprising at least one processing component

configured to assemble messages including measurements on satellite signals that are valid for a reference station and including an indication of a current movement of the reference station; and

configured to provide the assembled messages for transmission to a device.

26. An apparatus comprising:

means for adjusting a filter depending on information on a movement of a satellite signal receiver; and

means for determining a position of the satellite signal receiver relative to a reference station using the filter, wherein measurements on satellite signals received by the satellite signal receiver and measurements on satellite signals provided for the reference station are used as input to the filter.

27. A method comprising:

assembling messages including measurements on satellite signals that are valid for a reference station and including an indication of a current movement of the reference station; and

providing the assembled messages for transmission to a device.

28. The method according to claim 27, wherein the reference station is located at a fixed position.

29. The method according to claim 27, wherein the reference station is mobile and wherein the indication of a current movement of the reference station is determined from sensor information.

33. A computer program product in which program code is stored in a computer readable medium, the program code realizing the method of claim 27 when executed in a processor when executed in a processor.

30. An apparatus comprising at least one processing component

configured to assemble messages including measurements on satellite signals that are valid for a reference station and including an indication of a current movement of the reference station;

and

configured to provide the assembled messages for transmission to a device.

31. The apparatus according to claim 30, wherein the reference station is mobile and wherein the at least one processing component is configured to determine an indication of a current movement of the reference station from sensor information.

32. A device comprising:

an apparatus according to claim 30; and

an interface configured to enable a communication with another device.

34. An apparatus comprising:

means for assembling messages including measurements on satellite signals that are valid for a reference station and including an indication of a current movement of the reference station; and

means for providing the assembled messages for transmission to a device.