Position only fit, POF, algorithm for blur spot target tracking & discrimination

• US 20090144003A1
• Filed: 11/30/2007
• Published: 06/04/2009
• Est. Priority Date: 11/30/2007
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Murata, Ronald N.
• Granted Patent: US 8,655,614 B2
• Time in Patent Office: Days
• US Class Current: 702/66
• CPC Class Codes: G01J 5/0022 for sensing the radiation of moving bodies
• CPC Class Codes: G06T 7/00 Image analysis

Abstract

A method for determining the amplitude of an infrared object may include receiving an infrared image of the object from a sensor, and expressing the objects infrared amplitude as a function of its position coordinates. The sum of the squared residuals of the objects true infrared response and a model of the objects infrared response may be minimized to determine the centroid of the infrared image. The objects infrared amplitude may then determined based on the centroid location.

Claims

1. A method for determining an amplitude of an infrared object, comprising:

receiving an infrared image of the object from a sensor, the infrared image including an amplitude and position coordinates associated with the object;

expressing the amplitude as a function of the position coordinates;

minimizing a sum of squared residuals by subtracting and squaring the received infrared image of the object from a model of the received infrared image of the object, the model being expressed as a function of a point spread function of the sensor;

determining a centroid location of the model of the received infrared image of the object, and

determining the amplitude based at least in part on the centroid location.

2. The method of claim 1, further comprising:

receiving a plurality of infrared images of the object;

performing a Monte Carlo simulation using the plurality of infrared images; and

calculating one or more of a mean or a standard deviation for the amplitude or the centroid location.

3. The method of claim 2, wherein the Monte Carlo simulation comprises at least 32 trials.

4. The method of claim 1, flier comprising performing a frequency analysis based on the amplitude.

5. The method of claim 4, wherein the frequency analysis includes calculating one or more of a temperature, a temperature change, or a radiation intensity.

6. The method of claim 1, wherein the model is expressed as a Gaussian distribution.

7. The method of claim 1, wherein the model is expressed as a Bessel blur spot model.

8. The method of claim 1, wherein the position coordinates are one or more of an azimuth or an elevation angle.

9. The method of claim 1, wherein the centroid location is expressed in sub-pixel coordinates.

10. One or more computer readable storage media containing computer-executable instructions that, when executed by a processor, perform the following:

receive an infrared image of an object from a sensor, the infrared image including an amplitude and position coordinates associated with the object;

express the amplitude as a function of the position coordinates;

minimize a sum of squared residuals by subtracting and squaring the received infrared image from a model of the object'"'"'s infrared image, the model being expressed as a function of a point spread function of the sensor; and

determining a centroid location of the model of the received infrared image of the object, wherein the infrared amplitude is determined based at least in part on the centroid location.

11. The computer readable storage media of claim 10, further comprising computer executable instructions that when executed by a processor receives a plurality of infrared images of the object:

performs a Monte Carlo simulation using the plurality of infrared images; and

calculates one or more of a mean or a standard deviation for the infrared amplitude or the centroid location.

12. The computer readable storage media of claim 10, further comprising computer executable instructions that when executed by a processor performs a frequency analysis based on the amplitude.

13. The computer readable storage media of claim 12, wherein the frequency analysis includes calculating one or more of a temperature, a temperature change, or a radiation intensity.

14. The computer readable storage media of claim 10, wherein the centroid location is expressed in sub pixel coordinates.

15. A sensor system for determining the infrared amplitude of an object, comprising:

an infrared sensor configured to receive an infrared image; and

a processor operatively coupled to the infrared sensor, where in the processor comprises;

a first portion adapted to receive an infrared image of the object from the sensor, the infrared image including an amplitude and position coordinates associated with the object;

a second portion adapted to express the amplitude as a function of the position coordinates;

a third portion adapted to minimize a sum of squared residuals by subtracting and squaring the received infrared image of the object from a model of the received infrared image of the object, the model being expressed as a function of a point spread function of the sensor; and

a fourth portion adapted to determine a centroid location of the model of the received infrared image of the object, wherein the infrared amplitude is determined based on the centroid location.

16. The sensor system of claim 15, wherein the model is expressed as a Gaussian distribution.

17. The sensor system of claim 15, wherein the model is expressed as a Bessel blur spot model.

18. The sensor system of claim 15, further comprising a sixth portion adapted to perform a frequency analysis based on the amplitude.

19. The sensor system of claim 18, wherein the frequency analysis includes calculating one or more of a temperature, a temperature change, or a radiation intensity.

20. The sensor system of claim 15, further comprising an aircraft, the infrared sensor and processor being operatively coupled to the aircraft.