GNSS Positioning Using Pressure Sensors

• US 20150116150A1
• Filed: 01/06/2015
• Published: 04/30/2015
• Est. Priority Date: 06/08/2007
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Garin, Lionel Jacques
• Granted Patent: US 9,429,656 B2
• Time in Patent Office: Days
• US Class Current: 342/357.61
• CPC Class Codes: G01C 5/005 altimeters for aircraft G01C5/02, G01C5/06 take precedence
• CPC Class Codes: G01L 19/08 Means for indicating or recording, e.g. for remote indication
• CPC Class Codes: G01S 19/22 Multipath-related issues
• CPC Class Codes: G01S 19/45 by combining measurements of signals from the satellite radio beacon positioning system with a supplementary measurement

Abstract

Systems, methods and devices for improving the accuracy of GNSS data are provided. Specifically, embodiments of the invention can advantageously use sensor input to improve the accuracy of position fixes. The use of physical 5 sensors in navigation systems is deemed particularly advantageous, especially where altitude data derived from the pressure sensor is calibrated with and/or blended with GNSS altitude data.

Claims

1. A navigation receiver, comprising:

a pressure sensor configured to provide a pressure sensor signal;

a satellite receiver configured to provide pseudoranges associated with one or more satellites; and

one or more position filters configured to;

generate a position based, at least, on a pseudorange offset for a particular satellite of the one or more satellites, wherein the pseudorange offset, indicative of a multipath error of the particular satellite, is estimated from the pressure sensor signal and the pseudoranges associated with the one or more satellites.

2. The navigation receiver of claim 1, wherein the one or more position filters comprise:

a vertical position Kalman filter, in communication with the pressure sensor and the satellite receiver, the vertical position Kalman filter configured to;

calculate a barometric altitude based on the pressure sensor signal; and

estimate the pseudorange offset from the barometric altitude and the pseudoranges associated with the one or more satellites.

3. The navigation receiver of claim 2, wherein the one or more position filters further comprise:

a horizontal position Kalman filter, coupled to the vertical position Kalman filter, the horizontal position Kalman filter configured to generate a latitude and a longitude from at least the pseudorange offset for the particular satellite and the pseudoranges associated with the one or more satellites.

4. The navigation receiver of claim 1, wherein the one or more position filters are further configured to:

compensate one or more pseudoranges associated with the particular satellite by the pseudorange offset.

5. The navigation receiver of claim 1, wherein the one or more position filters are further configured to:

detect presence of multipath error for the particular satellite based on the pressure sensor signal and the pseudoranges associated with the one or more satellites.

6. The navigation receiver of claim 5, wherein the one or more position filters are further configured to:

calculate a GNSS altitude based on the pseudoranges associated with the one or more satellites;

calculate a barometric altitude based on the pressure sensor signal; and

wherein the detection of multipath error is based on a comparison between the GNSS altitude and the barometric altitude.

7. The navigation receiver of claim 5, wherein the one or more position filters are further configured to:

compute a first variation in GNSS altitudes based on the pseudoranges, corresponding to two GNSS position fixes;

compute a second variation in barometric altitudes based on the pressure sensor signal, corresponding to the two GNSS position fixes; and

wherein the detection of multipath error is based on a comparison between the first and the second variation.

8. The navigation receiver of claim 5, wherein the one or more position filters are further configured to:

calculate a barometric altitude based on the pressure sensor signal; and

determine a range in pseudorange variation for the particular satellite, based on at least the barometric altitude and a satellite position of the particular satellite.

9. A method in a navigation receiver, comprising:

obtaining a pressure sensor signal;

obtaining pseudoranges associated with one or more satellites; and

generating a position based, at least, on a pseudorange offset for a particular satellite of the one or more satellites, wherein the pseudorange offset, indicative of a multipath error of the particular satellite, is estimated from the pressure sensor signal and the pseudoranges associated with the one or more satellites.

10. The method of claim 9, further comprising:

calculating a barometric altitude based on the pressure sensor signal; and

estimating the pseudorange offset from the barometric altitude and the pseudoranges associated with the one or more satellites.

11. The method of claim 10, wherein the generating a position comprises:

generating a latitude and a longitude from at least the pseudorange offset for the particular satellite and the pseudoranges associated with the one or more satellites.

12. The method of claim 9, further comprising:

compensating one or more pseudoranges associated with the particular satellite by the pseudorange offset.

13. The method of claim 9, further comprising:

detecting presence of multipath error for the particular satellite based on the pressure sensor signal and the pseudoranges associated with the one or more satellites.

14. The method of claim 13, wherein the detecting presence of multipath error comprises:

calculating a GNSS altitude based on the pseudoranges associated with the one or more satellites;

calculating a barometric altitude based on the pressure sensor signal; and

wherein the detection of multipath error is based on a comparison between the GNSS altitude and the barometric altitude.

15. The method of claim 13, wherein the detecting presence of multipath error comprises:

computing a first variation in GNSS altitudes based on the pseudoranges, corresponding to two GNSS position fixes;

computing a second variation in barometric altitudes based on the pressure sensor signal, corresponding to the two GNSS position fixes; and

wherein the detection of multipath error is based on a comparison between the first and the second variation.

16. The method of claim 13, further comprising:

calculating a barometric altitude based on the pressure sensor signal; and

determining a range in pseudorange variation for the particular satellite, based on at least the barometric altitude and a satellite position of the particular satellite.

17. A navigation receiver, comprising:

means for obtaining a pressure sensor signal;

means for obtaining pseudoranges associated with one or more satellites; and

means for generating a position based, at least, on a pseudorange offset for a particular satellite of the one or more satellites, wherein the pseudorange offset, indicative of a multipath error of the particular satellite, is estimated from the pressure sensor signal and the pseudoranges associated with the one or more satellites.

18. The navigation receiver of claim 17, further comprising:

means for calculating a barometric altitude based on the pressure sensor signal; and

means for estimating the pseudorange offset from the barometric altitude and the pseudoranges associated with the one or more satellites.

19. The navigation receiver of claim 18, wherein the means for generating a position further comprises:

means for generating a latitude and a longitude from at least the pseudorange offset for the particular satellite and the pseudoranges associated with the one or more satellites.

20. The navigation receiver of claim 17, further comprising:

means for compensating one or more pseudoranges associated with the particular satellite by the pseudorange offset.

21. The navigation receiver of claim 17, further comprising:

means for detecting presence of multipath error for the particular satellite based on the pressure sensor signal and the pseudoranges associated with the one or more satellites.

22. The navigation receiver of claim 21, wherein the means for detecting presence of multipath error comprises:

means for calculating a GNSS altitude based on the pseudoranges associated with the one or more satellites;

means for calculating a barometric altitude based on the pressure sensor signal; and

wherein the detection of multipath error is based on a comparison between the GNSS altitude and the barometric altitude.

23. The navigation receiver of claim 21, wherein the means for detecting presence of multipath error comprises:

means for computing a first variation in GNSS altitudes based on the pseudoranges, corresponding to two GNSS position fixes;

means for computing a second variation in barometric altitudes based on the pressure sensor signal, corresponding to the two GNSS position fixes; and

wherein the detection of multipath error is based on a comparison between the first and the second variation.

24. The navigation receiver of claim 21, further comprising:

means for calculating a barometric altitude based on the pressure sensor signal; and

means for determining a range in pseudorange variation for the particular satellite, based on at least the barometric altitude and a satellite position of the particular satellite.

25. A processor-readable non-transitory medium having instructions stored thereon, which instructions when executed by at least one processor causes a navigation receiver to:

obtain a pressure sensor signal;

obtain pseudoranges associated with one or more satellites; and

generate a position based, at least, on a pseudorange offset for a particular satellite of the one or more satellites, wherein the pseudorange offset, indicative of a multipath error of the particular satellite, is estimated from the pressure sensor signal and the pseudoranges associated with the one or more satellites.