Detection system and method using gradient magnitude second moment spatial variance detection

• US 8,339,306 B2
• Filed: 11/02/2011
• Issued: 12/25/2012
• Est. Priority Date: 10/26/2006
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Bruyere, Donald P., Ashcraft, Ivan S., Treece, John B.
• Primary Examiner(s): GREGORY, BERNARR E
• Application Number:
  US13/288,009
• Publication Number:
  US 20120105275A1
• Time in Patent Office: 419 Days
• Field of Search: 702/127, 702189-199, 382/100, 382/107, 382/154, 382/162, 382/165, 382/181, 382/190, 382/195, 382/201, 382/232, 382/236, 342/21, 342/22, 342 25 R- 25 F, 342 26 R- 26 D, 342 70- 72, 342 89-103, 342159-164, 342/175, 342/176, 342/179, 342192-197
• US Class Current: 342/179
• CPC Class Codes: G01S 13/9004 SAR image acquisition techniques
• CPC Class Codes: G01S 7/411 Identification of targets based on measurements of radar reflectivity G01S7/415 takes precedence

Abstract

A detection system includes a detection processor configured to receive a frame of image data that includes a range/Doppler matrix, perform a rate-of-change of variance calculation with respect to at least one pixel in the frame of image data, and compare the calculated rate-of-change of variance with a predetermined threshold to provide output data. The range/Doppler matrix may include N down-range samples and M cross-range samples. The detection processor may calculate a rate-of-change of variance over an N×M window within the range/Doppler matrix.

Claims

1. A detection system comprising a detection processor configured to:

receive a frame of radar image data that includes a range/Doppler matrix;

perform a rate-of-change of variance calculation with respect to at least one pixel in the frame of radar image data; and

compare the calculated rate-of-change of variance with a predetermined threshold to provide output data.

2. The detection system of claim 1 wherein the range/Doppler matrix includes N down-range samples and M cross-range samples.

3. The detection system of claim 1 wherein the detection processor is configured to calculate a rate-of-change of variance over an N×

M window within the range/Doppler matrix.

4. The detection system of claim 3 wherein the detection processor is configured to output a rate-of-change of variance pixel map.

5. A detection system comprising a detection processor configured to:

receive a frame of radar image data;

perform a rate-of-change of variance calculation with respect to at least one pixel in the frame of radar image data;

compare the calculated rate-of-change of variance with a predetermined threshold to provide output data; and

identify a change in a standard deviation of a small, localized sampling of cells.

6. A detection method performed by a detection system comprising a detection processor, the method comprising:

receiving a frame of radar image data that includes a range/Doppler matrix;

performing a rate-of-change of variance calculation with respect to at least one pixel in the frame of radar image data; and

comparing the calculated rate-of-change of variance with a predetermined threshold to provide output data.

7. A system comprising:

a receiver;

an image processor coupled to the receiver; and

a detection processor coupled to the image processor, the detection processor having;

software for receiving a frame of radar image data;

software for performing a rate-of-change of variance calculation with respect to at least one pixel in the frame of radar image data; and

software for comparing the calculated rate-of-change of variance with a predetermined threshold to provide output data.

8. The system of claim 7 wherein the frame of radar image data includes a range/Doppler matrix.

9. The system of claim 8 wherein the range/Doppler matrix includes N down range samples and M cross range samples.

10. The system of claim 8 wherein the software for performing a rate-of-change of variance calculation includes software for calculating a rate-of-change of variance over an N×

M window within the range/Doppler matrix.

11. The system of claim 10 wherein the software for performing a rate-of-change of variance calculation outputs a rate-of-change of variance pixel map.

12. The system of claim 7 wherein the software for performing a rate-of-change of variance calculation includes software for identifying a change in a standard deviation of a small, localized sampling of cells.