Three-dimensional hyperspectral imaging systems and methods using a light detection and ranging (LIDAR) focal plane array

• US 9,448,110 B2
• Filed: 09/27/2012
• Issued: 09/20/2016
• Est. Priority Date: 09/27/2012
• Status: Active Grant

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Inventors: Wong, Chung Ming
• Primary Examiner(s): Ratcliffe, Luke
• Assistant Examiner(s): RODRIGUEZ, VICENTE M
• Application Number:
  US13/628,126
• Publication Number:
  US 20140085622A1
• Time in Patent Office: 1,454 Days
• Field of Search: 356/5.04
• US Class Current: 1/1
• CPC Class Codes: G01J 3/0278 Control or determination of height or angle information for sensors or receivers
• CPC Class Codes: G01J 3/2803 using photoelectric array detector
• CPC Class Codes: G01J 3/2823 Imaging spectrometer
• CPC Class Codes: G01J 3/4406 Fluorescence spectrometry
• CPC Class Codes: G01S 17/08 for measuring distance only indirect measurement G01S17/46; active triangulation systems G01S17/48
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 7/4802 using analysis of echo signal for target characterisation; Target signature; Target cross-section
• CPC Class Codes: G01S 7/4814 of transmitters alone
• CPC Class Codes: G01S 7/4816 of receivers alone
• CPC Class Codes: G01S 7/4863 Detector arrays, e.g. charge-transfer gates

Abstract

A system for three-dimensional hyperspectral imaging includes an illumination source configured to illuminate a target object; a dispersive element configured to spectrally separate light received from the target object into different colors; and a light detection and ranging focal plane array (FPA) configured to receive the light from the dispersive element, configured to acquire spatial information regarding the target object in one dimension in the plane of the FPA, configured to acquire spectral information in a second dimension in the plane of the FPA, wherein the second dimension is perpendicular to the first dimension, and configured to obtain information regarding the distance from the FPA to the target object by obtaining times of flight of at least two wavelengths, thereby imaging the target object in three dimensions and acquiring spectral information on at least one 3D point.

Claims

1. A system for three-dimensional (3D) hyperspectral imaging, comprising:

an illumination source configured to illuminate a target object;

a dispersive element configured to spectrally separate light received from the target object into different colors; and

a light detection and ranging (LIDAR) focal plane array (FPA) configured to receive the light from the dispersive element, configured to acquire spatial information regarding the target object in one dimension in the plane of the FPA, configured to acquire spectral information in a second dimension in the plane of the FPA, wherein the second dimension is perpendicular to the first dimension, configured to obtain information regarding a distance from the FPA to the target object by obtaining different times of flight of at least two wavelengths, and configured to detect a single photon of light, thereby hyperspectrally imaging the target object in three dimensions and acquiring spectral information on at least one 3D point.

2. The system of claim 1, further comprising an objective optical element, the objective optical element being configured to receive light from the target object and to collect the light.

3. The system of claim 1, further comprising a slit element configured to spatially filter the light.

4. The system of claim 3, wherein the slit element is further configured to spatially filter the light so as to define a spatial line in the spatial dimension of the FPA.

5. The system of claim 1, further comprising collimating optics configured to collimate the light.

6. The system of claim 1, further comprising focusing optics configured to refocus the light onto the FPA.

7. The system of claim 1, wherein the FPA samples the return signal at a selected sampling time interval.

8. The system of claim 1, wherein the system operates in push-broom mode.

9. The system of claim 1, wherein the system operates in whiskbroom mode.

10. The system of claim 1, wherein the illumination source comprises a white light laser.

11. The system of claim 1, wherein the illumination source is spatially reformatted into a line.

12. The system of claim 11, wherein the line is closely matched to the field of view of the FPA so as to optimize performance.

13. The system of claim 1, wherein the system is configured to measure spectral information regarding the target object.

14. The system of claim 1, wherein the system is configured to measure an excited state lifetime of the target object following illumination.

15. The system of claim 1, wherein the system is configured to measure spectral information regarding the target object hidden beneath canopy.

16. The system of claim 1, wherein the system is configured to remove shadowing effects and to reduce data holes in a hyperspectral data cube.

17. The system of claim 1, wherein the FPA comprises an integrated circuit.

18. The system of claim 17, wherein the integrated circuit is configured to operate in a threshold mode, wherein the integrated circuit counts time for at least one pixel comprised in the FPA upon the illumination of the target object by the illumination source.

19. The system of claim 17, wherein the integrated circuit is configured to operate in a gated mode, wherein existing knowledge of the target range is used by the integrated circuit to determine the time when counting time begins for at least one pixel comprised in the FPA.

20. The system of claim 1, wherein at least two detections are performed, and wherein the at least two detections are used to construct a histogram representing the spectral reflectivity of the target object.

21. The system of claim 1, wherein the FPA is configured to operate at a high repetition rate on the order of tens of kilohertz.

22. The system of claim 1, wherein the target object is a multilayer target object, and wherein at least two of the different times of flight are recordable by a single pixel that sees more than one layer of the multilayer target object.

23. A system for three-dimensional (3D) hyperspectral imaging, comprising:

an illumination source configured to illuminate a target object using broadband laser light;

an objective optical element configured to receive light from the target object and to collect the light;

a slit element configured to receive the light from the objective optical element and to spatially filter the light;

a dispersive element configured to spectrally separate the light into different colors;

collimating optics configured to collimate the light onto the dispersive element;

focusing optics configured to refocus the spectrally separated light; and

a light detection and ranging (LIDAR) focal plane array (FPA) configured to receive the light from the focusing optics and to detect a single photon of light, configured to acquire spatial information regarding the target object in one dimension in the plane of the FPA, configured to acquire spectral information in a second dimension in the plane of the FPA, wherein the second dimension is perpendicular to the first dimension, and configured to obtain information regarding a distance from the FPA to the target object by obtaining different times of flight of at least two wavelengths, thereby hyperspectrally imaging the target object in three dimensions and acquiring spectral information on at least one 3D point,

wherein at least two detections are performed to construct a histogram representing the spectral reflectivity of the target object.

24. A method for three-dimensional (3D) hyperspectral imaging, comprising:

providing a three-dimensional (3D) hyperspectral imaging apparatus comprising an illumination source, a dispersive element, and a light detection and ranging (LIDAR) focal plane array (FPA);

illuminating a target object with the illumination source;

using the dispersive element, spectrally separating light received from the target object into different colors;

using the 3D LIDAR FPA, receiving the spectrally separated light, detecting a single photon of light, acquiring spatial information regarding the target object in one dimension in the plane of the FPA, and acquiring spectral information regarding the target object in a second dimension in the plane of the FPA, wherein the second dimension is perpendicular to the first dimension; and

using the 3D LIDAR FPA, obtaining information regarding the distance from the FPA to the target object by obtaining different times of flight of at least two wavelengths, thereby hyperspectrally imaging the target object in three dimensions and acquiring spectral information on at least one 3D point.

25. A method for three-dimensional (3D) hyperspectral imaging, comprising:

providing a three-dimensional (3D) hyperspectral imaging apparatus comprising an illumination source, an objective optical element, a slit element, collimating optics, a dispersive element, focusing optics, and a light detection and ranging (LIDAR) focal plane array (FPA) configured to detect a single photon of light;

illuminating a target object with the illumination source;

receiving and collecting light from the target object using the objective optical element;

using the slit element, spatially filtering the light;

using the collimating optics, collimating the light onto the dispersive element;

using the dispersive element, spectrally separating the light into different colors;

using the focusing optics, refocusing the spectrally separated light;

using the 3D LIDAR FPA, receiving the refocused light from the focusing optics, acquiring spatial information regarding the target object in one dimension in the plane of the FPA, and acquiring spectral information regarding the target object in a second dimension in the plane of the FPA, wherein the second dimension is perpendicular to the first dimension; and

using the 3D LIDAR FPA, obtaining information regarding the distance from the FPA to the target object by obtaining different times of flight of at least two wavelengths, thereby hyperspectrally imaging the target object in three dimensions and acquiring spectral information on at least one 3D point.

26. A system, comprising:

an illumination source configured to illuminate a target object using broadband laser light;

a dispersive element configured to spectrally separate light received from the target object into different colors; and

a focal plane array (FPA) configured to receive the light from the dispersive element, configured to acquire spatial information regarding the target object in one dimension in the plane of the FPA, configured to acquire spectral information in a second dimension in the plane of the FPA, wherein the second dimension is perpendicular to the first dimension, configured to obtain information regarding the distance from the FPA to the target object by obtaining different times of flight of at least two wavelengths, and configured to detect a single photon of light, thereby hyperspectrally imaging the target object in three dimensions.

27. A system for three-dimensional (3D) hyperspectral imaging, comprising:

an illumination source configured to illuminate a target object;

a dispersive element configured to spectrally separate light received from the target object into different colors; and

a focal plane array (FPA) configured to receive the light from the dispersive element, configured to acquire spatial information regarding the target object in one dimension in the plane of the FPA, configured to acquire spectral information in a second dimension in the plane of the FPA, wherein the second dimension is perpendicular to the first dimension, configured to obtain information regarding the distance from the FPA to the target object by obtaining different times of flight of at least two wavelengths, and configured to detect a single photon of light, thereby acquiring hyperspectral information on at least one 3D point.