Autonomous navigation system based on GPS and magnetometer data

• US 6,760,664 B1
• Filed: 06/25/2002
• Issued: 07/06/2004
• Est. Priority Date: 06/25/2001
• Status: Expired due to Fees

• Current Assignee: The United States of America As Represented By The Secretary of Agriculture, United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Original Assignee: United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Inventors: Richard, Harman R., Julie, Thienel K., Bar-Itzhack, Itzhack Y.
• Primary Examiner(s): ARTHUR JEANGLAUDE, GERTRUDE
• Application Number:
  US10/178,546
• Time in Patent Office: 742 Days
• Field of Search: 701/200, 701/207, 701/213, 701/214, 701/215, 701/226, 342/357.06, 342/357.11, 342/357.12, 342/357.16
• US Class Current: 701/214
• CPC Class Codes: G01C 21/24 specially adapted for cosmonautical navigation
• CPC Class Codes: G01S 19/14 specially adapted for specific applications
• CPC Class Codes: G01S 19/45 by combining measurements of signals from the satellite radio beacon positioning system with a supplementary measurement
• CPC Class Codes: G01S 19/53 Determining attitude

Abstract

This invention is drawn to an autonomous navigation system using Global Positioning System (GPS) and magnetometers for low Earth orbit satellites. As a magnetometer is reliable and always provides information on spacecraft attitude, rate, and orbit, the magnetometer-GPS configuration solves GPS initialization problem, decreasing the convergence time for navigation estimate and improving the overall accuracy. Eventually the magnetometer-GPS configuration enables the system to avoid costly and inherently less reliable gyro for rate estimation. Being autonomous, this invention would provide for black-box spacecraft navigation, producing attitude, orbit, and rate estimates without any ground input with high accuracy and reliability.

Claims

1. An autonomous navigation system for determining a set of satellite navigation parameters including attitude, orbit, and rate, the system comprising:

a GPS receiver;

a magnetometer;

processing means for processing measurements from the GPS and magnetometer to estimate attitude, orbit, and rate.

2. The autonomous navigation system as in claim 1, wherein the measurements from the GPS comprises:

GPS pseudo-range; and

GPS phase measurements.

3. The autonomous navigation system as in claim 2, wherein the measurements from the GPS further comprises GPS range rate.

4. The autonomous navigation system as in claim 1, the processing means comprising:

an algorithm comprising a Kalman filter.

5. The autonomous navigation system as in claim 4, wherein output filter state of the Kalman filter includes:

6. The autonomous navigation system as in claim 5, wherein the rate estimate is obtained by applying derivative approach to GPS phase measurements or magnetometer measurements.

7. The autonomous navigation system as in claim 5, wherein the rate estimate is obtained by applying derivative approach to GPS phase measurements and magnetometer measurements.

8. The autonomous navigation system as in claim 4, wherein output filter state of the Kalman filter includes:

9. The autonomous navigation system as in claim 8, wherein the rate estimate is obtained by applying derivative approach to GPS phase measurements.

10. The autonomous navigation system as in claim 4, wherein output filter state of the Kalman filter includes:

11. The autonomous navigation system as in claim 10, wherein the rate estimate is obtained by applying derivative approach to magnetometer measurements.

12. The autonomous navigation system as in claim 4, wherein output filter state of the Kalman filter includes:

13. A method for estimating a set of navigation parameters of a satellite including attitude, orbit, and rate, the method comprising:

providing measurements from GPS;

providing measurements from magnetometer;

executing an algorithm to estimate attitude, orbit, and rate of the satellite based on the measurements from the GPS and magnetometer.

14. The method as in claim 13, wherein the measurements from the GPS comprises:

GPS pseudo-range; and

GPS phase measurements.

15. The method as in claim 14, wherein the measurements from the GPS further comprises GPS range rate.

16. The method as in claim 13, wherein the step of executing the algorithm includes performing Kalman filtering.

17. The method as in claim 16, wherein output filter state of the Kalman filter includes:

18. The method as in claim 17, wherein the rate estimate is obtained by applying derivative approach to GPS phase measurements or magnetometer measurements.

19. The method as in claim 17, wherein the rate estimate is obtained by applying derivative approach to GPS phase measurements and magnetometer measurements.

20. The method as in claim 16, wherein output filter state of the Kalman filter includes:

21. The method as in claim 20, wherein the rate estimate is obtained by applying derivative approach to GPS phase measurements.

22. The method as in claim 16, wherein output filter state of the Kalman filter includes:

23. The method as in claim 22, wherein the rate estimate is obtained by applying derivative approach to magnetometer measurements.

24. The method as in claim 16, wherein output filter state of the Kalman filter includes: