OPTIMIZED IMAGING SYSTEM FOR COLLECTION OF HIGH RESOLUTION IMAGERY

• US 20100202683A1
• Filed: 02/06/2009
• Published: 08/12/2010
• Est. Priority Date: 02/06/2009
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Robinson, Ian S.
• Granted Patent: US 8,290,301 B2
• Time in Patent Office: Days
• US Class Current: 382/164
• CPC Class Codes: G01J 2005/0077 Imaging
• CPC Class Codes: G01J 5/08 Optical arrangements
• CPC Class Codes: G01J 5/0846 having multiple detectors for performing different types of detection, e.g. using radiometry and reflectometry channels
• CPC Class Codes: G01J 5/10 using electric radiation detectors
• CPC Class Codes: G01N 2021/1793 Remote sensing
• CPC Class Codes: G01N 2021/3531 without instrumental source, i.e. radiometric
• CPC Class Codes: H04N 5/33 Transforming infrared radiation cameras or camera modules for generating image signals from infrared radiation H04N23/20; circuitry of SSIS for transforming infrared radiation into image signals H04N25/20

Abstract

Radiation is received from a scene impinging on at least one focal plane. A first spectral band is sampled to obtain a first band mean signal level, and either a first band image frame is collected when the first band mean signal level is at or below a first threshold, or a first image frame is collected in a first sub-band when the first band mean signal level is above the first threshold. A second sub-band is sampled to obtain a second sub-band mean signal level and a second image frame is collected in the second sub-band when the second sub-band mean signal level is at or below a second threshold. An image to be displayed is generated by combining at least two collected frames.

Claims

1. A method of providing an image of a scene utilizing imaging optics, the method comprising:

receiving radiation from the scene impinging on at least one focal plane;

sampling a first spectral band to obtain a first band mean signal level, the first spectral band comprising a first plurality of sub-bands;

collecting at least one first band image frame in the first spectral band when the first band mean signal level is at or below a first threshold;

collecting at least one first image frame in a first sub-band of the first plurality of sub-bands when the first band mean signal level is above the first threshold;

sampling a second sub-band of the first plurality of sub-bands to obtain a second sub-band mean signal level;

collecting at least one second sub-band image frame in the second sub-band when the second sub-band mean signal level is at or below a second threshold; and

generating an image to be displayed by combining at least two collected frames.

2. The method of claim 1, the method further comprising:

determining a first band minimum integration time to obtain the first band image frame from the first band mean signal level.

3. The method of claim 1, the method further comprising:

sampling the first sub-band of the first plurality of sub-bands to obtain a first sub-band mean signal level; and

determining a first sub-band minimum integration time to obtain the first image frame from the first sub-band mean signal level.

4. The method of claim 1, the method further comprising:

determining a second sub-band minimum integration time to obtain the at least one second sub-band image frame from the second sub-band mean signal level.

5. The method of claim 1, wherein the image to be displayed is a composite image.

6. The method of claim 1, wherein the image to be displayed is a band ratio image.

7. The method of claim 1, wherein the first sub-band of the plurality of sub-bands comprises at least a portion of an upper short-wave infrared sub-band.

8. The method of claim 1, wherein the second sub-band of the plurality of sub-bands comprises at least a portion of a lower short-wave infrared sub-band.

9. The method of claim 1, the method further comprising:

when the second sub-band mean signal level is above the second threshold,

adjusting a focal length of the imaging optics until a threshold signal level has been reached and collecting the at least one second sub-band image frame in the second sub-band,

wherein the image to be displayed is generated by combining at least two collected frames.

10. The method of claim 9, wherein the focal length of the imaging optics is adjusted until a threshold edge contrast ratio has been reached.

11. The method of claim 9, the method further comprising:

when the second sub-band mean signal level is above a third threshold,

collecting at least one image frame in a first portion of the second sub-band; and

collecting at least one image frame in a second portion of the second sub-band,

wherein the image to be displayed is generated by combining at least three collected frames.

12. The method of claim 11, wherein the first portion of the second sub-band comprises an upper half of a lower short-wave infrared sub-band.

13. The method of claim 11, wherein the second portion of the second sub-band comprises a lower half of a lower short-wave infrared sub-band.

14. The method of claim 11, the method further comprising:

sampling the first portion of the second sub-band to obtain a first portion mean signal level;

determining a first portion minimum integration time to obtain the at least one image frame in the first portion of the second sub-band from the first portion mean signal level;

sampling the second portion of the second sub-band to obtain a second portion mean signal level; and

determining a second portion minimum integration time to obtain the at least one image frame in the second portion of the second sub-band from the second portion mean signal level.

15. The method of claim 11, the method further comprising:

sampling a second spectral band to obtain a second band mean signal level, the second spectral band comprising a second plurality of sub-bands;

collecting at least one second band image frame in the second spectral band when the second band mean signal level is at or below a fourth threshold or above a fifth threshold, wherein the fifth threshold is higher than the fourth threshold,

wherein the image to be displayed is generated by combining at least two collected frames.

16. The method of claim 15, the method further comprising:

determining a second band minimum integration time to obtain the at least one second band image frame from the second band mean signal level.

17. The method of claim 15, the method further comprising:

when the second band mean signal level is at least above the fourth threshold,

collecting at least one image frame in a red sub-band of the second plurality of sub-bands;

collecting at least one image frame in a green sub-band of the second plurality of sub-bands; and

collecting at least one image frame in a blue sub-band of the second plurality of sub-bands,

wherein the image to be displayed is generated by combining at least four collected frames.

18. The method of claim 17, the method further comprising:

sampling the red sub-band of the second plurality of sub-bands to obtain a red sub-band mean signal level;

determining a red sub-band minimum integration time to obtain the at least one image frame in the red sub-band from the red sub-band mean signal level;

sampling the green sub-band of the second plurality of sub-bands to obtain a green sub-band mean signal level;

determining a green sub-band minimum integration time to obtain the at least one image frame in the green sub-band from the green sub-band mean signal level;

sampling the blue sub-band of the second plurality of sub-bands to obtain a blue sub-band mean signal level; and

determining a blue sub-band minimum integration time to obtain the at least one image frame in the blue sub-band from the blue sub-band mean signal level.

19. The method of claim 17, the method further comprising:

determining a remaining time of a maximum integration time; and

dividing the remaining time into a first time portion, a second time portion and a third time portion,

wherein the at least one image frame collected in the red sub-band is collected for the first time portion, the at least one image frame collected in the green sub-band is collected for the second time portion, and the at least one image frame collected in the blue sub-band is collected for the third time portion.

20. The method of claim 17, the method further comprising:

collecting at least one third band image frame in a third spectral band,

wherein the image to be displayed is generated by combining at least two collected frames.

21. The method of claim 20, wherein the third spectral band comprises at least a portion of a medium wave infrared band.

22. The method of claim 20, wherein the third spectral band comprises at least a portion of a panchromatic band.

28. The imaging system of claim 7, wherein the adaptive controller is further configured to collect at least one red sub-band image frame in a red sub-band of the second plurality of sub-bands for the first time portion, collect at least one green sub-band image frame in a green sub-band of the second plurality of sub-bands for the second time portion, and collect at least one blue sub-band image frame in a blue sub-band of the second plurality of sub-bands for the third time portion, when the second band mean signal level is at least above the fourth threshold,

wherein the image to be displayed is generated by combining at least four collected frames.

29. The imaging system of claim 28, wherein the adaptive controller is further configured to divide a remaining time of a maximum integration time into a first time portion, a second time portion, and a third time portion, and wherein the at least one red sub-band image frame is collected for the first time portion, the at least one green sub-band image frame is collected for the second time portion, and the at least one blue sub-band image frame is collected for the third time portion.

23. An imaging system for providing images of a scene comprising:

at least one focal plane for receiving radiation from the scene;

a spectral detector configured to transmit portions of a first spectral band to the at least one focal plane, wherein the first spectral band comprises a first plurality of sub-bands;

an adaptive controller configured to sample the first spectral band to obtain a first band mean signal level, collect at least one first band image frame in the first spectral band when the first band mean signal level is at or below the first threshold, collect at least one first sub-band image frame in a first sub-band of the plurality of sub-bands when the first band mean signal level is above the first threshold, sample a second sub-band of the first plurality of sub-bands to obtain a second sub-band mean signal level, and collect at least one second sub-band image frame in the second sub-band when the second sub-band mean signal level is at or below a second threshold; and

a data combiner configured to combine at least two collected frames to generate an image to be displayed.

24. The imaging system of claim 23, wherein the adaptive controller is further configured to adjust a focal length of the image optics until a threshold signal level has been reached, and collect the at least one second sub-band image frame in the second sub-band, when the second sub-band mean signal level is above the second threshold,

wherein the data combiner is further configured to combine at least two collected frames to generate the image to be displayed.

25. The imaging system of claim 23, wherein the adaptive controller is further configured to adjust a focal length of the image optics until a threshold edge contrast ratio has been reached, and collect the at least one second sub-band image frame in the second sub-band, when the second sub-band mean signal level is above the second threshold,

wherein the data combiner is further configured to combine at least two collected frames to generate the image to be displayed.

26. The imaging system of claim 24, wherein the adaptive controller is further configured to collect at least one image frame in a first portion of the second sub-band and collect at least one image frame in a second portion of the second sub-band, when the second sub-band mean signal level is above a third threshold,

wherein the data combiner is further configured to combine at least three collected frames to generate the image to be displayed.

27. The imaging system of claim 26, wherein the adaptive controller is further configured to sample a second spectral band to obtain a second band mean signal level, the second spectral band comprising a second plurality of sub-bands, and collect at least one second band image frame in the second spectral band when the second band mean signal level is at or below a fourth threshold or above a fifth threshold, wherein the fifth threshold is higher than the fourth threshold, and

wherein the data combiner is further configured to combine at least two collected frames to generate the image to be displayed.

30. A computer readable media embodying program instructions for execution by a data processing apparatus, the program instructions adapting the data processing apparatus for monitoring a network, the program instructions comprising:

receiving radiation from a scene impinging on at least one focal plane;

sampling a first spectral band to obtain a first band mean signal level, the first spectral band comprising a first plurality of sub-bands;

collecting at least one first band image frame in the first spectral band when the first band mean signal level is at or below a first threshold;

collecting at least one first sub-band image frame in a first sub-band of the first plurality of sub-bands when the first band mean signal level is above the first threshold;

sampling a second sub-band of the first plurality of sub-bands to obtain a second sub-band mean signal level;

collecting at least one second sub-band image frame in the second sub-band when the second sub-band mean signal level is at or below a second threshold;

when the second sub-band mean signal level is above the second threshold,

adjusting a focal length of the imaging optics until a threshold signal level has been reached and collecting the at least one second sub-band image frame in the second sub-band;

when the second sub-band mean signal level is above a third threshold,

collecting at least one image frame in a first portion of the second sub-band, and

collecting at least one image frame in a second portion of the second sub-band;

sampling a second spectral band to obtain a second band mean signal level, the second spectral band comprising a second plurality of sub-bands;

collecting at least one second band image frame in the second spectral band when the second band mean signal level is at or below a fourth threshold or above a fifth threshold, wherein the fifth threshold is higher than the fourth threshold;

when the second band mean signal level is at least above the fourth threshold,

dividing a remaining time of a maximum integration time into a first time portion, a second time portion, and a third time portion,

collecting at least one red sub-band image frame in a red sub-band of the second plurality of sub-bands for the first time portion,

collecting at least one green sub-band image frame in a green sub-band of the second plurality of sub-bands for the second time portion, and

collecting at least one blue sub-band image frame in a blue sub-band of the second plurality of sub-bands for the third time portion; and

generating an image to be displayed by combining at least two collected frames.

31. A method of obtaining imagery of ambient temperature objects at nighttime, the method comprising:

receiving radiation from a scene impinging on at least one focal plane;

sampling an upper short wave infrared band of a first band to obtain an upper short wave infrared mean signal level;

determining an upper short wave infrared band minimum integration time to obtain an upper short wave infrared frame from the upper short wave infrared mean signal level;

collecting the upper short wave infrared frame for the upper short wave infrared band minimum integration time; and

generating an image to be displayed from the upper short wave infrared frame.

32. The method of claim 31, the method further comprising:

sampling the first band to obtain a first band mean signal level;

when the first band mean signal level is below a first threshold,

sampling a lower short wave infrared band of the first band to obtain a lower short wave infrared mean signal level;

determining a lower short wave infrared band minimum integration time to obtain a lower short wave infrared frame from the lower short wave infrared mean signal level;

collecting the lower short wave infrared frame for the lower short wave infrared band minimum integration time;

when the first band mean signal level is above the first threshold,

sampling a lower short wave infrared band of the first band to obtain a lower short wave infrared mean signal level;

determining a lower short wave infrared band minimum integration time to obtain a lower short wave infrared frame from the lower short wave infrared mean signal level;

collecting the lower short wave infrared frame for the lower short wave infrared band minimum integration time; and

combining at least two frames to generate the image to be displayed.

33. The method of claim 32, the method further comprising:

collecting a medium wave infrared frame in a medium wave infrared band.

34. The method of claim 33, the method further comprising:

collecting a panchromatic frame in a panchromatic band.