Multi-spectral LADAR

• US 6,882,409 B1
• Filed: 06/25/2003
• Issued: 04/19/2005
• Est. Priority Date: 06/25/2003
• Status: Expired due to Fees

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Mitra, Pradip, Evans, Bruno J.
• Primary Examiner(s): Tarcza, Thomas H.
• Assistant Examiner(s): ANDREA, BRIAN K
• Application Number:
  US10/603,707
• Publication Number:
  US 20050068517A1
• Time in Patent Office: 664 Days
• Field of Search: 356 401- 515, 356/141.5, 356/305, 342/53, 250/339.01, 250/339.02, 250/339.05, 250/342
• US Class Current: 356/4.01
• CPC Class Codes: G01J 2003/2826 Multispectral imaging, e.g. filter imaging
• CPC Class Codes: G01J 3/0208 using focussing or collimating elements, e.g. lenses or mirrors; performing aberration correction
• CPC Class Codes: G01J 3/0264 Electrical interface; User interface
• CPC Class Codes: G01J 3/027 Control of working procedures of a spectrometer; Failure detection; Bandwidth calculation
• CPC Class Codes: G01J 3/0289 Field-of-view determination; Aiming or pointing of a spectrometer; Adjusting alignment; Encoding angular position; Size of measurement area; Position tracking
• CPC Class Codes: G01J 3/0291 Housings; Spectrometer accessories; Spatial arrangement of elements, e.g. folded path arrangements
• CPC Class Codes: G01J 3/10 Arrangements of light sources specially adapted for spectrometry or colorimetry
• CPC Class Codes: G01J 3/18 using diffraction elements, e.g. grating gratings per se G02B
• CPC Class Codes: G01J 3/26 using multiple reflection, e.g. Fabry-Perot interferometer, variable interference filters
• 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: G01S 17/87 Combinations of systems using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 17/894 3D imaging with simultaneous measurement of time-of-flight at a 2D array of receiver pixels, e.g. time-of-flight cameras or flash lidar
• CPC Class Codes: G01S 7/4802 using analysis of echo signal for target characterisation; Target signature; Target cross-section
• CPC Class Codes: G01S 7/481 Constructional features, e.g. arrangements of optical elements
• CPC Class Codes: G01S 7/4816 of receivers alone
• CPC Class Codes: G01S 7/4863 Detector arrays, e.g. charge-transfer gates

Abstract

A multi-spectral detector for use in a passive/active system and a method for use in identifying an object in a field of view are disclosed. The multi-spectral detection system comprises an optically dispersive element, a detector array, and an integrated circuit. The optically dispersive element is capable of separating received LADAR radiation and radiation received from a scene into a plurality of spectral components and distributing the separated spectral components; and a detector array. The detector array includes a plurality of detectors capable of detecting the LADAR radiation; and a plurality of detectors capable of detecting the spectral components of the scene radiation. The integrated circuit is capable of generating a plurality of electrical signals representative of predetermined characteristics of the detected LADAR radiation and the detected spectral components. The method comprises passively detecting scene radiation employing a detector array; and actively detecting LADAR radiation through the detector array in parallel with passively detecting the scene radiation.

Claims

1. A multi-spectral detector for use in a passive/active system, comprising:

an optically dispersive element capable of separating received LADAR radiation and radiation received from a scene into a plurality of spectral components and distributing the separated spectral components; and

a detector array including;

a plurality of detectors capable of detecting the LADAR radiation; and

a plurality of detectors capable of detecting the spectral components of the scene radiation; and

an integrated circuit capable of generating a plurality of electrical signals representative of predetermined characteristics of the detected LADAR radiation and the detected spectral components.

2. The detector of claim 1, wherein the optically dispersive element comprises a diffraction grating or a linear variable filter.

3. The detector of claim 2, wherein the optically dispersive element is integrated with the detector array.

4. The detector of claim 1, wherein the optically dispersive element is integrated with the detector array.

5. The detector of claim 1, wherein the detectors capable of detecting the LADAR radiation or the detectors capable of detecting the spectral components of the scene radiation comprise QWIPs or EQWIPs.

6. The detector of claim 1, wherein the detectors capable of detecting the LADAR radiation or the detectors capable of detecting the spectral components of the scene radiation have varied widths and are separated by varied pitches.

7. The detector of claim 6, wherein the detectors capable of detecting the LADAR radiation or the detectors capable of detecting the spectral components of the scene radiation comprise QWIPs or EQWIPs.

8. The detector of claim 1, wherein the detector array is integrated with the integrated circuit.

9. The detector of claim 8, wherein the optically dispersive element is integrated with the detector array.

10. A multi-spectral detector for use in a passive/active system, comprising:

means for distributing a plurality of spectral components of received LADAR radiation and radiation received from a scene;

means for detecting the distributed LADAR radiation;

means for detecting the spectral components of the infrared radiation; and

means for generating a plurality of electrical signals representative of predetermined characteristics of the detected LADAR radiation and the detected spectral components.

11. The detector of claim 10, wherein the distributing means diffracts the received LADAR and radiation.

12. The detector of claim 11, wherein the distributing means comprises a diffraction grating.

13. The detector of claim 10, wherein the distributing means comprises a diffraction grating.

14. The detector of claim 10, wherein the distributing means is integrated with the detecting means.

15. The detector of claim 10, wherein the detecting means comprises QWIPs or EQWIPs.

16. The detector of claim 10, wherein detecting means comprises a plurality of detectors have varied widths and are separated by varied pitches.

17. The detector of claim 10, wherein the detecting means is integrated with the generating means.

18. An imaging system, comprising:

a laser capable of transmitting LADAR radiation;

a multi-spectral detector for use in a passive/active system, comprising;

an optically dispersive element capable of separating received LADAR radiation and radiation received from a scene into a plurality of spectral components and distributing the separated spectral components; and

a detector array including;

a plurality of detectors capable of detecting the LADAR radiation; and

a plurality of detectors capable of detecting the spectral components of the scene radiation; and

an integrated circuit capable of generating a plurality of electrical signals representative of predetermined characteristics of the detected LADAR radiation and the detected spectral components; and

a processor for processing the electrical signals.

19. The imaging system of claim 18, wherein the optically dispersive element comprises a diffraction grating or a linear variable filter.

20. The imaging system of claim 18, wherein the optically dispersive element is integrated with the detector array.

21. The imaging system of claim 18, wherein the detectors capable of detecting the LADAR radiation or the detectors capable of detecting the spectral components of the scene radiation comprise QWIPs or EQWIPs.

22. The imaging system of claim 18, wherein the detectors capable of detecting the LADAR radiation or the detectors capable of detecting the spectral components of the scene radiation have varied widths and are separated by varied pitches.

23. The imaging system of claim 18, wherein the detector array is integrated with the integrated circuit.

24. A method for use in identifying an object in a field of view, comprising:

passively detecting radiation from a scene, the detection employing a detector array; and

actively detecting LADAR radiation through the detector array in parallel with passively detecting the scene radiation.

25. The method of claim 24, wherein passively detecting scene radiation includes passively detecting infrared radiation.

26. The method of claim 25, wherein passively detecting infrared radiation includes passively detecting hyperspectral infrared radiation.

27. The method of claim 24, wherein passively detecting scene radiation includes passively detecting hyperspectral scene radiation.

28. The method of claim 24, further comprising receiving the scene and LADAR radiation through the same optical train.

29. The method of claim 28, wherein detecting the scene and LADAR radiation includes separating the received LADAR and scene radiation into a plurality of spectral components and distributing the separated spectral components across the detector array.

30. The method of claim 24, further comprising generating a plurality of electrical signals representative of predetermined characteristics of the detected LADAR radiation and the detected spectral components.

31. An apparatus for use in identifying an object in a field of view, comprising:

means for passively detecting scene radiation employing a detector array; and

means for actively detecting LADAR radiation through the detector array in parallel with passively detecting the scene radiation.

32. The apparatus of claim 31, wherein the means for passively detecting scene radiation includes means for passively detecting infrared radiation.

33. The apparatus of claim 31, wherein the means for passively detecting scene radiation includes means for passively detecting hyperspectral scene radiation.

34. The apparatus of claim 31, further comprising means for receiving the scene and LADAR radiation through the same optical train.

35. The apparatus of claim 31, further comprising means for generating a plurality of electrical signals representative of predetermined characteristics of the detected LADAR radiation and the detected spectral components.

44. The apparatus of claim 31, further comprising:

means for separating received LADAR radiation and radiation received from a scene into a plurality of spectral components; and

means for distributing the separated spectral components across the detector array.

36. A method, comprising:

receiving LADAR and scene radiation from a field of view;

separating the received LADAR and scene radiation into a plurality of spectral components;

directing the spectral components to respective detectors;

detecting the spectral components; and

generating an electrical signal representative of predetermined characteristics of the detected spectral components.

37. The method of claim 36, wherein receiving the scene radiation includes receiving infrared radiation.

38. The method of claim 36, wherein receiving the scene radiation includes receiving hyperspectral scene radiation.

39. The method of claim 36, wherein receiving the scene and LADAR radiation includes receiving the scene and LADAR radiation through the same optical train.

40. An apparatus, comprising:

means for receiving LADAR and scene radiation from a field of view;

means for separating the received LADAR and scene radiation into a plurality of spectral components;

means for directing the spectral components to respective detectors;

means for detecting the spectral components; and

means for generating an electrical signal representative of predetermined characteristics of the detected spectral components.

41. The apparatus of claim 40, wherein the means for receiving the scene radiation includes means for receiving infrared radiation.

42. The apparatus of claim 40, wherein the means for receiving the scene radiation includes means for receiving hyperspectral scene radiation.

43. The apparatus of claim 40, wherein the means for receiving the scene and LADAR radiation includes means for receiving the scene and LADAR radiation through the same optical train.