System and methods for explosives detection using SWIR

• US 20110089323A1
• Filed: 10/06/2010
• Published: 04/21/2011
• Est. Priority Date: 10/06/2009
• Status: Active Grant

• Current Assignee: Chemimage Corporation
• Original Assignee: Chemimage Corporation
• Inventors: Gardner, Charles W. JR., Nelson, Matthew, Treado, Patrick
• Granted Patent: US 9,103,714 B2
• Time in Patent Office: Days
• US Class Current: 250/330
• CPC Class Codes: G01J 3/02 Details
• CPC Class Codes: G01J 3/0218 using optical fibers
• CPC Class Codes: G01J 3/027 Control of working procedures of a spectrometer; Failure detection; Bandwidth calculation
• CPC Class Codes: G01J 3/0278 Control or determination of height or angle information for sensors or receivers
• CPC Class Codes: G01J 3/44 Raman spectrometry; Scattering spectrometry ; Fluorescence spectrometry
• CPC Class Codes: G01N 21/359 using near infrared light
• CPC Class Codes: G01N 33/0057 Warfare agents or explosives

Abstract

A system and method for detecting explosives and explosive residues. A region of interest is surveyed using a video capture device to thereby identify a target area wherein the target area comprises an unknown material. The target area is interrogated using SWIR spectroscopic methods to form a SWIR hyperspectral image of the target area. The SWIR hyperspectral image is analyzed to thereby identify the unknown material.

Claims

1. A system comprising:

a telescope optics for focusing and locating at least one of;

a region of interest, a target area, a unknown material, and combinations thereof;

a visible imaging device configured for generating a visible image of at least one of;

a region of interest, a target area, an unknown material, and combinations thereof;

a tunable filter configured to sequentially filter at least one plurality of interacted photons into a plurality of predetermined wavelength bands;

a SWIR imaging device configured for generating a SWIR hyperspectral image of at least one of;

a region of interest, a target area, an unknown material, and combinations thereof.

2. The system of claim 1 wherein said visible imaging device is configured so as to operate in a targeting mode.

3. The system of claim 1 wherein said SWIR imaging device is configured to operate in at least one of:

a targeting mode, an identification mode, and combinations thereof.

4. The system of claim 1 further comprising an illumination source for illuminating at least one of:

a region of interest, a target area, an unknown material, and combinations thereof.

5. The system of claim 4 wherein said illumination source is selected from the group consisting of:

a laser light source, a broadband light source, an ambient light source and combinations thereof.

6. The system of claim 1 wherein said visible imaging device comprises a RGB camera.

7. The system of claim 1 wherein said visible imaging device comprises a video capture device.

8. The system of claim 1 wherein said tunable filter is selected from the group consisting of:

a SWIR multi-conjugate liquid crystal tunable filter, a SWIR liquid crystal tunable filter and combinations thereof.

9. The system of claim 1 wherein said tunable filter is selected from the group consisting of:

a Fabry Perot angle tuned filter, an acousto-optic tunable filter, a liquid crystal tunable filter, a Lyot filter, an Evans split element liquid crystal tunable filter, a Solc liquid crystal tunable filter, a fixed wavelength Fabry Perot tunable filter, an air-tuned Fabry Perot tunable filter, a mechanically-tuned Fabry Perot tunable filter, and a liquid crystal Fabry Perot tunable filter.

10. The system of claim 1 wherein said SWIR imaging device comprises a SWIR InGaAs camera.

11. The system of claim 1 further comprising at least one of:

a SWIR zoom optic, a RGB zoom optic, a range finder, and combinations thereof.

12. The system of claim 1 further comprising a reference data base wherein said reference data base comprises at least one of a visible reference data set and a SWIR reference data set, wherein each of said visible reference data sets and said SWIR reference data sets are associated with a known material.

13. The system of claim 12 further comprising a means for comparing at least one of said visible image and said SWIR hyperspectral image to said reference data base.

14. The system of claim 1 wherein said visible-image comprises a dynamic visible image.

15. The system of claim 1 wherein said SWIR hyperspectral image comprises a dynamic SWIR hyperspectral image.

16. The system of claim 1 wherein said system is stationary and configured to detect one or more moving target areas.

17. The system of claim 1 wherein said system is configured for on-the-move detection of one or more stationary target areas.

18. The system of claim 1 wherein said system is configured for on-the-move detection of one or more moving target areas.

19. The system of claim 1 further comprising a means for fusing said visible image and said SWIR hyperspectral image to thereby generate a fused image.

20. The system of claim 1 wherein said unknown material comprises at least one of:

an explosive material, a non-explosive material, an explosive residue, a material associated with an explosive material, and combinations thereof.

21. The system of claim 1 wherein said telescope optics is configured so as to effectively increase the magnification of at least one of:

a region of interest, a target area, an unknown material, and combinations thereof.

22. A method comprising:

surveying a region of interest to thereby identify a target area wherein said target area comprises an unknown material;

illuminating said target area to thereby generate a first plurality of interacted photons;

passing said first plurality of interacted photons through a tunable filter;

assessing said first plurality of interacted photons using a spectroscopic imaging device to thereby generate a SWIR hyperspectral image representative of said target area.

23. The method of claim 22 wherein said SWIR hyperspectral image comprises a digital image and a spatially resolved SWIR spectra for each pixel in said image.

24. The method of claim 22 further comprising analyzing said SWIR hyperspectral image to thereby identify said unknown material present in said target area.

25. The method of claim 24 wherein said analyzing comprises comparing said SWIR hyperspectral image to a reference data base wherein said reference data set comprises at least one SWIR reference data set wherein each SWIR reference data set is associated with a known material.

26. The method of claim 25 wherein said comparing is achieved using at least one chemometric technique.

27. The method of claim 22 wherein said target area is selected based on at least one of size of said target area, shape of said target area, color of said target area, and combinations thereof.

28. The method of claim 22 wherein said surveying of said region of interest is accomplished using a visible imaging device.

29. The method of claim 28 wherein said visible imaging device generates a visible image representative of said region of interest.

30. The method of claim 29 wherein said visible image comprises a dynamic visible image of said region of interest.

31. The method of claim 28 wherein said visible imaging device comprises a RGB camera.

32. The method of claim 22 wherein said SWIR hyperspectral image comprises a dynamic SWIR hyperspectral image.

33. The method of claim 22 further comprising analyzing said SWIR hyperspectral image to thereby identify said unknown material.

34. The method of claim 33 wherein said analyzing may further comprise comparing said SWIR hyperspectral image to a reference database wherein said reference database comprises at least one reference SWIR data set associated with a known material.

35. The method of claim 34 wherein said comparison is achieved using a chemometric technique.

36. The method of claim 22 wherein said illumination is accomplished using an illumination source selected from the group consisting of:

an ambient light source, a broadband light source, a laser illumination source, and combinations thereof.

37. The method of claim 22 wherein said first plurality of interacted photons are selected from the group consisting of:

photons reflected by said target area, photons absorbed by said target area, photons scattered by said target area, photons emitted by said target area and combinations thereof.

38. The method of claim 22 wherein said unknown material comprises at least one of:

an explosive material, a non-explosive material, an explosive residue, a material associated with an explosive material, and combinations thereof.

39. The method of claim 22 wherein said tunable filter is selected from the group consisting of:

a SWIR multi-conjugate liquid crystal tunable filter, a SWIR liquid crystal tunable filter and combinations thereof.

40. The method of claim 22 wherein said tunable filter is selected from the group consisting of:

a Fabry Perot angle tuned filter, an acousto-optic tunable filter, a liquid crystal tunable filter, a Lyot filter, an Evans split element liquid crystal tunable filter, a Solc liquid crystal tunable filter, a fixed wavelength Fabry Perot tunable filter, an air-tuned Fabry Perot tunable filter, a mechanically-tuned Fabry Perot tunable filter, and a liquid crystal Fabry Perot tunable filter.

41. The method of claim 22 further comprising applying a fusion algorithm to said visible image and said SWIR hyperspectral image.

42. The method of claim 22 further comprising obtaining at least one of:

a MWIR hyperspectral image of said target area, a LWIR hyperspectral image representative of said target area, and combinations thereof.

43. The method of claim 42 further comprising applying a fusion algorithm to at least two of:

said visible image, said SWIR hyperspectral image, said MWIR hyperspectral image, and said LWIR hyperspectral image.

44. The method of claim 22 wherein a telescope optics is configured so as to focus and locate at least one of:

said region of interest, said target area, said unknown material, and combinations thereof.

45. The method of claim 22 wherein a telescope optics is configured so as to collect said first plurality of interacted photons.

46. The method of claim 22 wherein a telescope optics is configured so as to effectively increase the magnification of at least one of:

said region of interest, said target area, said unknown material, and combinations thereof.