Gps-based measurement of roll rate and roll angle of spinning platforms

• US 20100117894A1
• Filed: 01/09/2008
• Published: 05/13/2010
• Est. Priority Date: 01/09/2008
• Status: Active Grant

• Current Assignee: Mayflower Communications Co., Inc.
• Original Assignee: Mayflower Communications Co., Inc.
• Inventors: Tseng, Huan-Wan, Upadhyay, Triveni, Velde, Wallace Vander, Cafarella, John, Dimos, George
• Granted Patent: US 7,994,971 B2
• Time in Patent Office: Days
• US Class Current: 342/357.360
• CPC Class Codes: G01S 19/48 by combining or switching between position solutions derived from the satellite radio beacon positioning system and position solutions derived from a further system
• CPC Class Codes: G01S 19/54 using carrier phase measurements; using long or short baseline interferometry

Abstract

A system and method for determining the roll rate and roll angle of a spinning platform, using the measured phase differences between the GPS satellite signals received on two or more antennas. The measured phase differences and the navigation solution from a GPS receiver are processed in a Kalman filter to obtain the desired information. Data from non-GPS measurement sources is optionally provided to update the navigation solution. Although of wide applicability, the invention is uniquely suited to the measurement of roll rates and roll angles of fast spinning platforms with small baselines, in which the antennas are separated from each other by distances that are a fraction of the GPS signal wavelength.

Claims

1. A system for determining the roll rate and roll angle of a spinning platform comprising:

at least two antennas for receiving GPS signals from at least one satellite;

a GPS receiver for tracking the GPS signals and forming the navigation solution;

a roll processor, driven by the GPS receiver, for correlating the received antenna signals, measuring the phase differences between the correlated signals, and processing the measured phase differences and navigation solution to determine roll rate and roll angle.

2. The system of claim 1, wherein the antennas are pointed in different directions.

3. The system of claim 2, wherein the antennas are circumferentially disposed on the platform about its spin axis.

4. The system of claim 2, wherein the spacing between the antennas is a fraction of the GPS signal wavelength.

5. The system of claim 1, wherein the roll processor includes a Kalman filter for processing the measured phase differences and navigation solution to determine roll rate and roll angle.

6. A system for determining the roll rate and roll angle of a spinning platform comprising:

at least two antennas for receiving GPS signals from at least one satellite;

a GPS receiver for tracking the GPS signals and forming the navigation solution; and

means for synchronously correlating the received antenna signals, measuring the phase differences between the correlated signals, and processing the measured phase differences and navigation solution to determine roll rate and roll angle.

7. The system of claim 6, wherein the antennas are pointed in different directions.

8. The system of claim 7, wherein the antennas are circumferentially disposed on the platform about its spin axis.

9. The system of claim 7, wherein the spacing between the antennas is a fraction of the GPS signal wavelength.

10. The system of claim 6, wherein the means for synchronously correlating the received antenna signals includes driving the correlators using the GPS receiver.

11. The system of claim 10, wherein the means for processing the measured phase differences and navigation solution includes a Kalman filter.

12. A system for determining the roll rate and roll angle of a spinning platform comprising:

at least two antennas for receiving GPS signals from at least one satellite;

a GPS receiver for tracking the GPS signals and forming the navigation solution;

at least one non-GPS measurement source for updating the navigation solution; and

a roll processor, driven by the GPS receiver, for correlating the received antenna signals, measuring the phase differences between the correlated signals, and processing the measured phase differences and updated navigation solution to determine roll rate and roll angle.

13. The system of claim 12, wherein the antennas are pointed in different directions.

14. The system of claim 13, wherein the spacing between the antennas is a fraction of the GPS signal wavelength.

15. The system of claim 12, wherein the roll processor includes a Kalman filter for processing the measured phase differences and updated navigation solution to determine roll rate and roll angle.

16. The system of claim 15, wherein the non-GPS measurement source is an inertial measurement unit.

17. The system of claim 15, wherein the non-GPS measurement source is a magnetometer.

18. A method for determining the roll rate and roll angle of a spinning platform comprising the steps of:

receiving GPS signals from at least one satellite on at least two antennas;

tracking the GPS signals and forming the navigation solution;

correlating the received antenna signals;

measuring the phase differences between the correlated signals; and

processing the measured phase differences and navigation solution to determine roll rate and roll angle.

19. The system of claim 18, wherein the antennas are pointed in different directions.

20. The system of claim 19, wherein the antennas are circumferentially disposed on the platform about its spin axis.

21. The method of claim 19, wherein the spacing between the antennas is a fraction of the GPS signal wavelength.

22. The method of claim 18, wherein processing the measured phase differences and navigation solution includes using a Kalman filter.

23. A method for determining the roll rate and roll angle of a spinning platform comprising the steps of:

receiving GPS signals from at least one satellite on at least two antennas;

tracking the GPS signals and forming the navigation solution;

updating the navigation solution using at least one non-GPS measurement source;

correlating the received antenna signals;

measuring the phase differences between the correlated signals; and

processing the measured phase differences and updated navigation solution to determine roll rate and roll angle.

24. The system of claim 23, wherein the antennas are pointed in different directions.

25. The system of claim 24, wherein the antennas are circumferentially disposed on the platform about its spin axis.

26. The method of claim 24, wherein the spacing between the antennas is a fraction of the GPS signal wavelength.

27. The method of claim 23, wherein processing the measured phase differences and updated navigation solution includes using a Kalman filter.

28. The method of claim 27, wherein the non-GPS measurement source is an inertial measurement unit.

29. The method of claim 27, wherein the non-GPS measurement source is a magnetometer.