Dynamic ray traversing

• US 7,567,205 B1
• Filed: 09/18/2008
• Issued: 07/28/2009
• Est. Priority Date: 09/18/2008
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Lee, Chul J.
• Primary Examiner(s): Tarcza; Thomas H
• Assistant Examiner(s): Bythrow; Peter M
• Application Number:
  US12/212,786
• Time in Patent Office: 313 Days
• Field of Search: 342159-164, 342/169, 342/175, 342/186, 345/421, 345/423, 345/426
• US Class Current: 342/169
• CPC Class Codes: G01S 7/418 Theoretical aspects
• CPC Class Codes: G06T 15/06 Ray-tracing

Abstract

In one aspect, a method to generate radar signatures for multiple objects in motion, includes performing a shooting and bouncing (SBR) technique to solve for physical optics and multi-bounce characteristics associated with the objects. Performing the SBR technique includes performing dynamic ray tracing to form an image of an object having surfaces and edges. Performing the dynamic ray tracing includes transforming the object in a common coordinate frame of reference to a centered-body axis frame of reference.

Claims

1. A method to generate radar signatures for multiple objects in motion, comprising:

performing a shooting and bouncing (SBR) technique to solve for physical optics and multi-bounce characteristics associated with the objects, the performing comprising performing dynamic ray tracing to form an image of an object having surfaces and edges,

wherein performing dynamic ray tracing comprises transforming the object in a common coordinate frame of reference to a centered-body axis frame of reference.

2. The method of claim 1 wherein performing the dynamic ray tracing further comprises traversing a ray on the transformed object using a binary space tree.

3. The method of claim 2 wherein performing the dynamic ray tracing further comprises:

receiving the binary space tree corresponding to the object on the centered-body axis frame of reference at a first location; and

receiving data on the object after movement, the data being associated with the object at a second location on the common coordinate frame of reference.

4. The method of claim 1 wherein performing the SBR technique comprises performing far field calculations on the surfaces and the edges of the image.

5. The method of claim 1 wherein transforming the object in a common coordinate frame of reference to a centered-body axis frame of reference comprises:

receiving a data file comprising an orientation/translation matrix; and

using the orientation/translation matrix to perform the transforming.

6. An apparatus to generate radar signatures for multiple objects in motion, comprising:

circuitry to;

perform a shooting and bouncing (SBR) technique to solve for physical optics and multi-bounce characteristics associated with the objects, the circuitry to perform the SBR technique comprising circuitry to perform dynamic ray tracing to form an image of an object having surfaces and edges,

wherein circuitry to perform dynamic ray tracing comprises circuitry to transform the object in a common coordinate frame of reference to a centered-body axis frame of reference.

7. The apparatus of claim 6 wherein the circuitry comprises at least one of a processor, a memory, programmable logic and logic gates.

8. The apparatus of claim 6 wherein the circuitry to perform the dynamic ray tracing further comprises circuitry to traverse a ray on the transformed object using a binary space tree.

9. The apparatus of claim 8 wherein the circuitry to perform the dynamic ray tracing further comprises circuitry to:

receive the binary space tree corresponding to the object on the centered-body axis frame of reference at a first location; and

receive data on the object after movement, the data being associated with the object at a second location on the common coordinate frame of reference.

10. The apparatus of claim 6 wherein the circuitry to perform the SBR technique comprises circuitry to perform far field calculations on the surfaces and the edges of the image.

11. The apparatus of claim 6 wherein the circuitry to transform the object in a common coordinate frame of reference to a centered-body axis frame of reference comprises circuitry to:

receive a data file comprising an orientation/translation matrix; and

use the orientation/translation matrix to perform transforming.

12. An article comprising:

a machine-readable medium that stores executable instructions to generate radar signatures for multiple objects in motion, the instructions causing a machine to;

perform a shooting and bouncing (SBR) technique to solve for physical optics and multi-bounce characteristics associated with the objects, the instructions causing a machine to perform comprising the instructions causing a machine to perform dynamic ray tracing to form an image of an object having surfaces and edges,

wherein the instructions causing a machine to perform dynamic ray tracing comprises instructions causing a machine to transform the object in a common coordinate frame of reference to a centered-body axis frame of reference.

13. The article of claim 12 wherein the instructions causing a machine to perform the dynamic ray tracing further comprises instructions causing a machine to traverse a ray on the transformed object using a binary space tree.

14. The article of claim 13 wherein the instructions causing a machine to perform the dynamic ray tracing further comprises circuitry to:

receive the binary space tree corresponding to the object on the centered-body axis frame of reference at a first location; and

receive data on the object after movement, the data being associated with the object at a second location on the common coordinate frame of reference.

15. The article of claim 12 wherein the instructions causing a machine to perform the SBR technique comprises instructions causing a machine to perform far field calculations on the surfaces and the edges of the image.

16. The article of claim 12 wherein the instructions causing a machine to transform the object in a common coordinate frame of reference to a centered-body axis frame of reference comprises instructions causing a machine to:

receive a data file comprising an orientation/translation matrix; and

use the orientation/translation matrix to perform transforming.

17. A method to generate radar signatures for multiple objects, comprising:

performing in parallel a shooting and bouncing (SBR) technique to solve for physical optics and multi-bounce characteristics of a plurality of objects in motion, a physical theory (PTD) technique to solve for material edges of the objects and a incremental length diffraction coefficient (ILDC) to solve for material boss/channel;

coherently integrating the results from the SBR, PTD and ILDC techniques by frequency; and

generating the RCS values of the plurality of objects,

wherein performing the SBR technique comprises;

evaluating rays independently; and

performing dynamic ray tracing to form an image of an object having the surfaces and the materiel edges, and

wherein performing dynamic ray tracing comprises;

transforming the object in a common coordinate frame of reference to a centered-body axis frame of reference; and

traversing a ray on the transformed object using a binary space tree.

18. The method of claim 17 wherein performing the dynamic ray tracing further comprises:

receiving the binary space tree corresponding to the object on the centered-body axis frame of reference at a first location;

receiving data on the object after movement, the data being associated with the object at a second location on the common coordinate frame of reference.

19. The method of claim 18 wherein performing the SBR technique comprises performing far field calculations on the surfaces and the material edges of the image.

20. The method of claim 19 wherein transforming the object in a common coordinate frame of reference to a centered-body axis frame comprises:

receiving a data file comprising an orientation/translation matrix; and

using the orientation/translation matrix to perform the transforming.