TIME AND SPACE RESOLVED STANDOFF HYPERSPECTRAL IED EXPLOSIVES LIDAR DETECTION

• US 20080198365A1
• Filed: 06/09/2006
• Published: 08/21/2008
• Est. Priority Date: 07/14/2005
• Status: Active Grant

• Current Assignee: Chemimage Corporation
• Original Assignee: Chemimage Corporation
• Inventors: Nelson, Matthew P., Treado, Patrick J., Neiss, Jason, Hubble, Hugh W.
• Granted Patent: US 7,692,775 B2
• Time in Patent Office: Days
• US Class Current: 356/73
• CPC Class Codes: G01J 3/02 Details
• CPC Class Codes: G01J 3/0221 the fibers defining an entry slit
• CPC Class Codes: G01J 3/0264 Electrical interface; User interface
• CPC Class Codes: G01J 3/2823 Imaging spectrometer
• CPC Class Codes: G01J 3/36 Investigating two or more bands of a spectrum by separate detectors
• CPC Class Codes: G01J 3/44 Raman spectrometry; Scattering spectrometry ; Fluorescence spectrometry
• CPC Class Codes: G01N 2021/1738 Optionally different kinds of measurements; Method being valid for different kinds of measurement
• CPC Class Codes: G01N 2021/174 either absorption-reflection or emission-fluorescence
• CPC Class Codes: G01N 2021/1744 either absorption or scatter
• CPC Class Codes: G01N 21/359 using near infrared light
• CPC Class Codes: G01N 21/6456 Spatial resolved fluorescence measurements; Imaging
• CPC Class Codes: G01N 21/65 Raman scattering
• CPC Class Codes: G01N 21/718 Laser microanalysis, i.e. with formation of sample plasma

Abstract

A system and method for standoff detection of explosives and explosive residue. A laser light source illuminates a target area having an unknown sample producing luminescence emitted photons, scattered photons and plasma emitted photons. A first optical system directs light to the target area. A video capture device outputs a dynamic image of the target area. A second optical system collects photons, and directs collected photons to a first two-dimensional array of detection elements and/or to a fiber array spectral translator device which device includes a two-dimensional array of optical fibers drawn into a one-dimensional fiber stack. A spectrograph is coupled to the one-dimensional fiber stack of the fiber array spectral translator device, wherein the entrance slit of the spectrograph is coupled to the one dimensional fiber stack.

Claims

1. A system comprising:

a laser light source configured to illuminate a target area having an unknown sample, to thereby produce luminescence emitted photons, scattered photons and plasma emitted photons from different locations on or within the unknown sample;

a first optical system coupled to said laser light source to direct light to the target area having the unknown sample;

a video capture device that outputs a dynamic image of the target area;

a first two-dimensional array of detection elements;

a second optical system that collects said luminescence emitted, said scattered, and said plasma emitted photons, and directs the collected luminescence emitted photons to said first two-dimensional array of detection elements coupled to said second optical system and further directs the collected scattered and plasma emitted photons to a fiber array spectral translator device coupled to said second optical system;

wherein said first two-dimensional array detects in a spatially accurate manner said luminescence emitted photons received from said second optical system and generates at least one of the following;

a plurality of spatially resolved fluorescence spectra, and

a plurality of spatially accurate wavelength resolved fluorescence images;

wherein said fiber array spectral translator device outputs at least one of the following received from said second optical system;

said collected plasma emitted photons, and

said collected scattered photons,

and includes a two-dimensional array of optical fibers drawn into a one-dimensional fiber stack so as to effectively convert a two-dimensional field of view into a curvilinear field of view;

a photodiode coupled to said first optical system to generate a gating signal to synchronize an acquisition time of a second two dimensional array of detection elements with a pulse width of laser light emanating from said laser light source;

a spectrograph coupled to said one-dimensional fiber stack of said fiber array spectral translator device, wherein an entrance slit of the spectrograph is coupled to said one dimensional fiber stack to perform at least one of the following;

disperse said scattered photons output by the fiber array spectral translator device to generate a plurality of spatially resolved Raman spectra, and disperse said plasma emitted photons output by the fiber array spectral translator device to generate a plurality of spatially resolved atomic spectra; and

wherein said second two dimensional array of detection elements coupled to said spectrograph detects the plurality of spatially resolved Raman spectra or the plurality of spatially resolved atomic spectra produced by said spectrograph.

2. The system of claim 1, wherein said laser source comprises a Nd:

YAG laser that illuminates the sample using pulsed illumination at a first wavelength of 1064 nm to produce plasma emitted photons, illuminates the sample at a second wavelength of 532 nm to produce Raman scattered photons and illuminates the sample at a third wavelength of 266 nm to produce luminescence emitted photons.

3. The system of claim 1, wherein said laser light source illuminates the sample with structured illumination.

4. The system of claim 1, further comprising a telescope used to locate and focus on the target area, said telescope coupled to the first optical system.

5. The system of claim 1, further comprising a near infrared camera using an ambient light source to illuminate the target area having the unknown sample.

6. The system of claim 1, further comprising a targeting scope coupled to said video capture device.

7. The system of claim 1, further comprising:

a filter that sequentially filters collected luminescence emitted photons in each of a plurality of predetermined wavelength bands and directs the filtered luminescence emitted photons to the first two dimensional array of detection elements coupled thereto.

8. The system of claim 1, further comprising:

instructions executable by at least one processor that apply a fusion algorithm to two or more of the plurality of spatially resolved fluorescence spectra, the plurality of spatially resolved Raman spectra and the plurality of spatially resolved atomic spectra, in order to identify the unknown sample.

9. The system of claim 1, further comprising at least one processor configured to generate a plurality of control signals, wherein said control signals include:

first control signals that control operation of the laser light source;

second control signals that control operation of the second optical system such that the second optical system directs the collected luminescence emitted photons to a filter and directs the collected scattered photons and the plasma emitted photons to the fiber array spectral translator device; and

third control signals that control operation of the filter such that the filter sequentially filters collected luminescence emitted photons, in each of a plurality of predetermined wavelength bands.

10. The system of claim 9, further comprising at least one processor configured to generate a plurality of further instructions, for sequentially configuring the system in a luminescence emitted mode, a Raman mode and a LIBS mode, wherein said instructions include:

wherein, in said luminescence emitted mode, the first control signals control operation of the laser light source in order to produce luminescence emitted photons from different locations on or within the unknown sample, the second control signals control the operation of the second optical system such that the second optical system directs the collected luminescence emitted photons to the filter, the third control signals control operation of the filter such that the filter sequentially filters collected luminescence emitted photons, in each of a plurality of predetermined wavelength bands;

wherein, in said Raman mode, the first control signals control operation of the laser light source in order to produce scattered photons from different locations on or within the unknown sample, the second control signals control the operation of the second optical system such that the second optical system directs the collected scattered photons to the fiber array spectral translator device; and

wherein, in said LIBS mode, the first control signals control operation of the laser light source in order to produce plasma emitted photons from different locations on or within the unknown sample, the second control signals control the operation of the second optical system such that the second optical system directs the collected plasma emitted photons to the fiber array spectral translator device.

11. A system comprising:

a laser light source configured to illuminate a target area having an unknown sample, to thereby produce scattered photons and plasma emitted photons from different locations on or within the sample;

a broadband light source that illuminates the sample with broadband light to thereby produce photons reflected from different locations on or within the unknown sample,

a first optical system coupled to said laser light source to direct light to the target area having the unknown sample;

a video capture device that outputs a dynamic image of the target area;

a first two-dimensional array of detection elements;

a second optical system that collects said reflected, said scattered, and said plasma emitted photons, and directs the collected reflected photons to said first two-dimensional array of detection elements coupled to said second optical system and further directs the collected scattered and plasma emitted photons to a fiber array spectral translator device coupled to said second optical system;

wherein said first two-dimensional array detects in a spatially accurate manner said reflected photons received from said second optical system to thereby generate one or more of;

a plurality of spatially accurate wavelength resolved infrared images and a plurality of spatially resolved infrared spectra;

wherein said fiber array spectral translator device outputs at least one of the following received from said second optical system;

said collected plasma emitted photons, and

said collected scattered photons,

and includes a two-dimensional array of optical fibers drawn into a one-dimensional fiber stack so as to effectively convert a two-dimensional field of view into a curvilinear field of view;

a photodiode coupled to said first optical system to generate a gating signal to synchronize an acquisition time of a second two dimensional array of detection elements with a pulse width of laser light emanating from said laser light source;

a spectrograph coupled to said one-dimensional fiber stack of said fiber array spectral translator device, wherein an entrance slit of the spectrograph is coupled to said one dimensional fiber stack to perform at least one of the following;

disperse said scattered photons output by the fiber array spectral translator device to generate a plurality of spatially resolved Raman spectra, and disperse said plasma emitted photons output by the fiber array spectral translator device to generate a plurality of spatially resolved atomic spectra; and

wherein said second two dimensional array of detection elements coupled to said spectrograph detects the plurality of spatially resolved Raman spectra or the plurality of spatially resolved atomic spectra produced by said spectrograph.

12. The system of claim 11, wherein said laser source comprises a Nd:

YAG laser that illuminates the sample using pulsed illumination at a first wavelength of 1064 nm to produce plasma emitted photons and illuminates the sample at a second wavelength of 532 nm to produce Raman scattered photons.

13. The system of claim 11, wherein said laser source illuminates the sample with structured illumination.

14. The system of claim 11 said first optical system further comprising a telescope used to locate and focus on the target area, said telescope coupled to the first optical system.

15. The system of claim 11, further comprising a near infrared camera using an ambient light source to illuminate the target area having the unknown sample.

16. The system of claim 11, further comprising a targeting scope coupled to said video capture device.

17. The system of claim 11, further comprising:

a filter that sequentially filters collected reflected photons in each of a plurality of predetermined wavelength bands and directs the filtered reflected photons to the infrared two dimensional array of detection elements coupled thereto.

18. The system of claim 11, further comprising:

instructions executable by at least one processor that apply a fusion algorithm to two or more of the plurality of spatially resolved infrared spectra, the plurality of spatially resolved Raman spectra and the plurality of spatially resolved atomic spectra, in order to identify the unknown sample.

19. The system of claim 11, further comprising at least one processor configured to generate a plurality of control signals, wherein said control signals include:

first control signals that control operation of the laser light source and the broad band light source;

second control signals that control operation of the second optical system such that the second optical system directs the collected reflected photons to a filter and directs the collected scattered photons and the plasma emitted photons to the fiber array spectral translator device; and

third control signals that control operation of the filter such that the filter sequentially filters collected reflected photons, in each of a plurality of predetermined wavelength bands.

20. The system of claim 19, further comprising at least one processor configured to generate a plurality of further instructions, for sequentially configuring the system in an infrared mode, a Raman mode and a LIBS mode, wherein said instructions include:

wherein, in said infrared mode, the first control signals control operation of the broadband light source in order to produce photons reflected from different locations on or within the unknown sample, the second control signals control the operation of the second optical system such that the second optical system directs the collected reflected photons to the filter, the third control signals control operation of the filter such that the filter sequentially filters collected reflected photons, in each of a plurality of predetermined wavelength bands;

wherein, in said Raman mode, the first control signals control operation of the laser light source in order to produce scattered photons from different locations on or within the unknown sample, the second control signals control the operation of the second optical system such that the second optical system directs the collected scattered photons to the fiber array spectral translator device; and

wherein, in said LIBS mode, the first control signals control operation of the laser light source in order to produce plasma emitted photons from different locations on or within the unknown sample, the second control signals control the operation of the second optical system such that the second optical system directs the collected plasma emitted photons to the fiber array spectral translator device.

21. A system comprising:

a laser light source configured to illuminate a target area having an unknown sample, to thereby produce luminescence emitted photons, scattered photons and plasma emitted photons from different locations on or within the sample;

a broadband light source that illuminates the sample with broadband light to thereby produce photons reflected from different locations on or within the unknown sample,

a first optical system coupled to said laser light source to direct light to the target area having the unknown sample;

a video capture device that outputs a dynamic image of the target area;

a first two-dimensional array of detection elements;

an infrared two-dimensional array of detection elements;

a second optical system that collects said luminescence emitted, said reflected, said scattered, and said plasma emitted photons, and directs the collected luminescence emitted photons to said first two-dimensional array of detection elements coupled, directs the collected reflected photons to said infrared two-dimensional array of detection elements coupled to said second optical system, and further directs the collected scattered and plasma emitted photons to a fiber array spectral translator device coupled to said second optical system;

wherein said first two-dimensional array detects in a spatially accurate manner said luminescence emitted photons received from said second optical system to thereby generate a plurality of spatially resolved fluorescence spectra;

wherein said infrared two-dimensional array detects in a spatially accurate manner said reflected photons received from said second optical system;

wherein said fiber array spectral translator device outputs at least one of the following received from said second optical system;

said collected plasma emitted photons, and

said collected scattered photons,

and includes a two-dimensional array of optical fibers drawn into a one-dimensional fiber stack so as to effectively convert a two-dimensional field of view into a curvilinear field of view;

a photodiode coupled to said first optical system to generate a gating signal to synchronize an acquisition time of a second two dimensional array of detection elements with a pulse width of laser light emanating from said laser light source;

a spectrograph coupled to said one-dimensional fiber stack of said fiber array spectral translator device, wherein an entrance slit of the spectrograph is coupled to said one dimensional fiber stack to perform at least one of the following;

disperse said scattered photons output by the fiber array spectral translator device to generate a plurality of spatially resolved Raman spectra, and disperse said plasma emitted photons output by the fiber array spectral translator device to generate a plurality of spatially resolved atomic spectra; and

wherein said second two dimensional array of detection elements coupled to said spectrograph detects the plurality of spatially resolved Raman spectra or the plurality of spatially resolved atomic spectra produced by said spectrograph.

22. The system of claim 21, wherein said laser source comprises a Nd:

YAG laser that illuminates the sample using pulsed illumination at a first wavelength of 1064 nm to produce plasma emitted photons, illuminates the sample at a second wavelength of 532 nm to produce Raman scattered photons and illuminates the sample at a third wavelength of 266 nm to produce luminescence emitted photons.

23. The system of claim 21, wherein said laser source illuminates the sample with structured illumination.

24. The system of claim 21, said first optical system further comprising a telescope used to locate and focus on the target area, said telescope coupled to the first optical system.

25. The system of claim 21, further comprising a near infrared camera using an ambient light source to illuminate the target area having the unknown sample.

26. The system of claim 21, further comprising a targeting scope coupled to said video capture device.

27. The system of claim 21, further comprising:

a filter that sequentially filters collected reflected photons and directs the reflected photons to the infrared two dimensional array of detection elements coupled thereto and sequentially filters collected luminescence emitted photons in each of a plurality of predetermined wavelength bands and directs the luminescence emitted photons to the first two dimensional array of detection elements coupled thereto.

28. The system of claim 21, further comprising:

instructions executable by at least one processor that apply a fusion algorithm to two or more of the plurality of spatially resolved fluorescence spectra, the plurality of spatially resolved Raman spectra and the plurality of spatially resolved atomic spectra, in order to identify the unknown sample.

29. The system of claim 21, further comprising at least one processor configured to generate a plurality of control signals, wherein said control signals include:

first control signals that control operation of the laser light source and the broadband light source;

second control signals that control operation of the second optical system such that the second optical system directs the collected reflected photons and the luminescence emitted photons to a filter and directs the collected scattered photons and the plasma emitted photons to the fiber array spectral translator device; and

third control signals that control operation of the filter such that the filter sequentially filters collected reflected photons and collected luminescence emitted photons, in each of a plurality of predetermined wavelength bands; and

fourth control signals that control operation of steering mirror such that the steering mirror directs the luminescence emitted photons to the first two dimensional array of detection elements and directs the reflected photons to the infrared two dimensional array of detection elements.

30. The system of claim 29, further comprising at least one processor configured to generate a plurality of further instructions, for sequentially configuring the system in a luminescence emitted mode, an infrared mode, a Raman mode and a LIBS mode, wherein said instructions include:

wherein, in said luminescence emitted mode, the first control signals control operation of the laser light source in order to produce luminescence emitted photons from different locations on or within the unknown sample, the second control signals control the operation of the second optical system such that the second optical system directs the collected luminescence emitted photons to the filter, the third control signals control operation of the filter such that the filter sequentially filters collected luminescence emitted photons, in each of a plurality of predetermined wavelength bands, the fourth control signals such that a steering mirror directs the luminescence emitted photons to the first two dimensional array of detection elements;

wherein, in said infrared mode, the first control signals control operation of the broadband light source in order to produce photons reflected from different locations on or within the unknown sample, the second control signals control the operation of the second optical system such that the second optical system directs the collected reflected photons to the filter, the third control signals control operation of the filter such that the filter sequentially filters collected reflected photons, in each of a plurality of predetermined wavelength bands, the fourth control signals such that a steering mirror directs the reflected photons to the infrared two dimensional array of detection elements;

wherein, in said Raman mode, the first control signals control operation of the laser light source in order to produce scattered photons from different locations on or within the unknown sample, the second control signals control the operation of the second optical system such that the second optical system directs the collected scattered photons to the fiber array spectral translator device, and

wherein, in said LIBS mode, the first control signals control operation of the laser light source in order to produce plasma emitted photons from different locations on or within the unknown sample, the second control signals control the operation of the second optical system such that the second optical system directs the collected plasma emitted photons to the fiber array spectral translator device.

31. A method comprising:

surveying an above ground area to identify a region of interest based on at least one of size, shape and color of the region of interest;

illuminating the region of interest with a plurality of photons to thereby produce emitted photons from the region of interest;

analyzing the emitted photons, produced by the region of interest, using fluorescence spectroscopy to produce at least one of the following;

a plurality of spatially resolved fluorescence spectra and a plurality wavelength resolved fluorescence images;

using at least one of the following to identify a target area;

the plurality of spatially resolved fluorescence spectra and the plurality wavelength resolved fluorescence images;

illuminating the target area with a plurality of photons to thereby produce Raman scattered photons and plasma emitted photons from the target area;

collecting, via a fiber array spectral translator device, Raman scattered photons and plasma emitted photons produced by the target area, wherein said device comprises a two dimensional array of optical fibers drawn into a one dimensional fiber stack so as to effectively convert a two-dimensional field of view into a curvilinear field of view;

analyzing the Raman scattered photons, produced by the target area, using Raman spectroscopy to produce a plurality of spatially resolved Raman spectra;

analyzing the plasma emitted photons, produced by the target area, using laser induced breakdown spectroscopy to produce a plurality of spatially resolved atomic spectra; and

applying a fusion algorithm to at least two of the following to identify one or more chemical compounds in the target area;

the plurality of spatially resolved fluorescence spectra, the plurality of spatially resolved Raman spectra and the plurality of spatially resolved atomic spectra.

32. The method of claim 31, wherein said chemical compound comprises residue of an explosive material.

33. A method comprising:

surveying a subsurface area to identify a region of interest based on at least one of size, shape and color of the region of interest;

illuminating the region of interest with a plurality of photons to thereby produce reflected photons from the region of interest;

analyzing the reflected photons, produced by the region of interest, using near infrared spectroscopy to produce at least one of the following;

a plurality of spatially resolved near infrared spectra and a plurality wavelength resolved near infrared images;

using at least one of the following to identify a target area;

the plurality of spatially resolved near infrared spectra and the plurality wavelength resolved near infrared images;

illuminating the target area with a plurality of photons to thereby produce Raman scattered photons and plasma emitted photons from the target area;

collecting, via a fiber array spectral translator device, Raman scattered photons and plasma emitted photons produced by the target area, wherein said device comprises a two dimensional non-linear array of optical fibers drawn into a one dimensional fiber stack so as to effectively convert a two-dimensional field of view into a curvilinear field of view;

analyzing the Raman scattered photons, produced by the target area, using Raman spectroscopy to produce a plurality of spatially resolved Raman spectra;

analyzing the plasma emitted photons, produced by the target area, using laser induced breakdown spectroscopy to produce a plurality of spatially resolved atomic spectra; and

applying a fusion algorithm to at least two of the following to identify one or more chemical compounds in the target area;

the plurality of spatially resolved near infrared spectra, the plurality of spatially resolved Raman spectra and the plurality of spatially resolved atomic spectra.