System and method for geo-registration with global positioning and inertial navigation

• US 7,395,156 B2
• Filed: 06/23/2005
• Issued: 07/01/2008
• Est. Priority Date: 06/23/2005
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Chiou, Kuo-Liang, Rudolph, Kevin E., Chiou, Carroll C.
• Primary Examiner(s): Tran; Dalena
• Application Number:
  US11/159,475
• Publication Number:
  US 20060293854A1
• Time in Patent Office: 1,104 Days
• Field of Search: 701/301, 701/200, 701/207, 701/220, 701/223, 701/208, 701/225, 342/25.A, 342/25.R, 342 63- 65, 342/53, 342/357.01, 180/167, 180/169
• US Class Current: 701/301
• CPC Class Codes: G01S 13/867 Combination of radar systems with cameras
• CPC Class Codes: G01S 13/90 using synthetic aperture techniques , e.g. synthetic aperture radar [SAR] techniques
• CPC Class Codes: G01S 19/21 Interference related issues ; Issues related to cross-correlation, spoofing or other methods of denial of service
• CPC Class Codes: G01S 19/47 the supplementary measurement being an inertial measurement, e.g. tightly coupled inertial
• CPC Class Codes: G01S 7/40 Means for monitoring or calibrating

Abstract

A position estimation system including a first arrangement for providing an image with a known target in a known reference frame. A second arrangement correlates the image with a stored image. The correlation is used to compute an error with respect to a position estimate. In a specific embodiment, the error is referenced with respect to first (x), second (y) and third (z) directions. A target location error is computed with respect to a stored image provided by a target image catalog. The target image catalog includes target geo-locations and digital terrain elevation data. In an illustrative application, the image data is provided by synthetic aperture radar and forward-looking infrared systems. An observation model and a measure noise matrix are Kalman filtered to ascertain a position error in navigation data generated by an integrated inertial navigation and Global Positioning system.

Claims

1. A position estimation system comprising:

first means for providing an image including a known target in a known reference frame;

second means for correlating said image with a stored image;

third means responsive to said second means for computing an error in response thereto, wherein said error is referenced with respect to first (x), second (y) and third (z) directions;

fourth means responsive to said third means for providing an observation model; and

fifth means for filtering said model to provide a position estimate.

2. The invention of claim 1 wherein said error is a target location error.

3. The invention of claim 1 wherein said stored image is provided by a catalog.

4. The invention of claim 3 wherein said catalog is a target image catalog.

5. The invention of claim 4 wherein said target image catalog includes target geo-locations.

6. The invention of claim 5 wherein said catalog includes digital terrain elevation data.

7. The invention of claim 1 wherein said fifth means includes a Kalman filter.

8. The invention of claim 1 further including means for providing position data and means for computing said error in response thereto.

9. The invention of claim 8 wherein said means for providing position data includes an inertial navigation system.

10. The invention of claim 9 further including means for providing errors with respect to a slant coordinate frame.

11. The invention of claim 10 further including means for converting said errors with respect to a slant coordinate frame to errors with respect to a platform coordinate frame.

12. The invention of claim 9 wherein said means for providing position data further includes a Global Positioning System receiver.

13. The invention of claim 1 wherein said first means includes a radar system.

14. The invention of claim 13 wherein said radar system includes a synthetic aperture radar.

15. The invention of claim 1 wherein said first means includes an infrared detector.

16. The invention of claim 15 wherein said first means includes a forward-looking infrared detector.

17. The invention of claim 1 further including means for providing an observation matrix.

18. The invention of claim 1 further including means for providing a measurement noise matrix.

19. The invention of claim 1 further including means for using an observation matrix and a measurement noise matrix to correct for said error.

20. A navigation system comprising:

an inertial navigation system;

a Global Positioning System receiver for minimizing an error generated by said inertial navigation system;

means for minimizing an err or in position data generated by said inertial navigation system in response to an output from said receiver, wherein said error is referenced with respect to first (x), second (y) and third (z) directions;

means for detecting interference in reception of said receiver and providing a signal in response thereto;

responsive to said signal for referencing data from target in a known location to minimize an error generated by said inertial navigation system;

means responsive to said means for minimizing for providing an observation model; and

means for filtering said model to provide a position estimate.

21. A position estimation method including the steps of:

providing an image including a known target in a known reference frame;

correlating said image with a stored image;

computing an error in response said step of correlating said image with a stored image, wherein said error is referenced with respect to first (x), second (y) and third (z) directions;

providing an observation model in, response to said error; and

filtering said model to provide a position estimate.

22. The invention of claim 21 wherein said error is referenced with respect to first (x), second (y) and third (z) directions.

23. The invention of claim 21 wherein said error is a target location error.

24. The invention of claim 21 wherein said stored image is provided by a catalog.

25. The invention of claim 24 wherein said catalog is a target image catalog.

26. The invention of claim 25 wherein said target image catalog includes target geo-locations.

27. The invention of claim 26 wherein said catalog includes digital terrain elevation data.

28. The invention of claim 21 further including the step of providing an observation model.

29. The invention of claim 28 further including the step of filtering said model to provide a position estimate.

30. The invention of claim 29 wherein said filtering is effected with a Kalman filter.

31. The invention of claim 21 further including the step of providing position data and means for computing said error in response thereto.

32. The invention of claim 31 wherein said step of providing position data includes the step of securing position data from an inertial navigation system.

33. The invention of claim 32 further including the step of providing errors with respect to a slant coordinate frame.

34. The invention of claim 33 further including the step of converting said errors with respect to a slant coordinate frame to errors with respect to a platform coordinate frame.

35. The invention of claim 32 wherein said step of providing position data further includes a Global Positioning System receiver.

36. The invention of claim 21 further including the step of providing an observation matrix.

37. The invention of claim 21 further including the step of providing a measurement noise matrix.

38. The invention of claim 21 further including the step of using an observation matrix and a measurement noise matrix to correct for said error.

39. A navigation method including the steps of:

providing an inertial navigation system;

providing a Global Positioning System;

minimizing an error in position data generated by said inertial navigation system in response to an output from said receiver, wherein said error is referenced with respect to first (x), second (y) and third (z) directions;

detecting interference in reception of said receiver and providing a signal in response thereto;

referencing data from a target in a known location to minimize an error generated by said inertial navigation system in response to said signal;

providing an observation model in response to said error; and

filtering said model to provide a position estimate.

40. A position estimation system comprising:

first means for providing an image including a known target in a known reference frame;

second means for correlating said image with a stored image;

third means responsive to said second means for computing a position estimate error in response thereto, wherein said error is referenced with respect to first (x), second (y) and third (z) directions;

fourth means for providing an observation matrix;

fifth means for providing a measurement noise matrix; and

sixth means for using an observation matrix and a measurement noise matrix to correct for said error.