Range imaging lidar

• US 8,427,649 B2
• Filed: 05/15/2010
• Issued: 04/23/2013
• Est. Priority Date: 05/15/2009
• Status: Active Grant

• Current Assignee: Michigan Aerospace Corporation
• Original Assignee: Michigan Aerospace Corporation
• Inventors: Hays, Paul Byron, Johnson, David Keith, Zuk, David Michael
• Primary Examiner(s): Chowdhury, Tarifur
• Assistant Examiner(s): HANSEN, JONATHAN M
• Application Number:
  US12/780,895
• Publication Number:
  US 20110164783A1
• Time in Patent Office: 1,074 Days
• Field of Search: 356/450, 356/4.01, 356/4.09
• US Class Current: 356/450
• CPC Class Codes: G01S 17/003 Bistatic lidar systems; Multistatic lidar systems
• CPC Class Codes: G01S 17/58 Velocity or trajectory determination systems; Sense-of-movement determination systems
• CPC Class Codes: G01S 17/95 for meteorological use
• CPC Class Codes: Y02A 90/10 Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Abstract

Light scattered by a portion of a fluid medium illuminated by a beam of substantially monochromatic light is received within a field-of-view nominally along an axis oriented in a different direction relative to the beam and processed by an interferometer to generate a corresponding fringe pattern that is detected and processed to generate at least one measure of the fluid medium at a plurality of different ranges.

Claims

1. A method of remotely sensing a fluid medium, comprising:

a. receiving scattered light from a portion of said fluid medium, wherein said scattered light is generated along a first beam of substantially monochromatic light projected into said fluid medium along a first axis, and the operation of receiving said scattered light is nominally along a second axis that is oriented in a different direction relative to said first axis;

b. forming an image of said scattered light through an interferometer, wherein said image of said scattered light comprises a first plurality of fringes, and each fringe of said first plurality of fringes is associated with a different portion of said portion of said fluid medium at a different range;

c. detecting at least a portion of said image of said first plurality of fringes of said scattered light so as to generate a corresponding plurality of detected signals;

d. analyzing at least a first fringe of said first plurality of fringes embodied in said plurality of detected signals so as to determine at least one measure of said fluid medium within a first portion of said fluid medium at a first range; and

e. analyzing at least a second fringe of said first plurality of fringes embodied in said plurality of detected signals so as to determine at least one measure of said fluid medium within at least a second portion of said fluid medium at least a second range, wherein said first portion of said fluid medium is different from said second portion of said fluid medium, and said first range is different from said second range.

2. A method of remotely sensing a fluid medium as recited in claim 1, further comprising:

a. receiving a portion of said substantially monochromatic light from a source thereof as a reference source; and

b. detecting said reference source, wherein the operations of analyzing said at least said first fringe of said first plurality of fringes and analyzing said at least said second fringe of said first plurality of fringes are responsive to at least one corresponding reference signal detected from said reference source.

3. A method of remotely sensing a fluid medium as recited in claim 2, wherein the operation of detecting said reference source comprises detecting an intensity of said reference source.

4. A method of remotely sensing a fluid medium as recited in claim 2, further comprising:

a. forming an image of said reference source through said interferometer, wherein said image of said reference source comprises at least a second fringe; and

b. processing said at least said second fringe, wherein the operations of analyzing said at least said first fringe of said first plurality of fringes and analyzing said at least said second fringe of said first plurality of fringes are responsive to the operation of processing said at least said second fringe.

5. A method of remotely sensing a fluid medium as recited in claim 4, further comprising interleaving said substantially monochromatic light of said reference source with said scattered light prior to forming said images of said scattered light and said reference source through said interferometer.

6. A method of remotely sensing a fluid medium as recited in claim 5, further comprising masking a portion of said reference source prior to the operation of interleaving said substantially monochromatic light of said reference source with said scattered light, so as to prevent a more than insubstantial overlap of said first plurality of fringes with said at least said second fringe in said images of said scattered light and said reference source through said interferometer.

7. A method of remotely sensing a fluid medium as recited in claim 6, wherein the operation of masking said portion of said reference source comprises blocking said portion of said reference source from transmission to said interferometer.

8. A method of remotely sensing a fluid medium as recited in claim 6, wherein the operation of masking said portion of said reference source comprises controllably reflecting said portion of said reference source away from said interferometer.

9. A method of remotely sensing a fluid medium as recited in claim 5, further comprising masking a portion of said scattered light prior to the operation of interleaving said substantially monochromatic light of said reference source with said scattered light, so as to prevent a more than insubstantial overlap of said first plurality of fringes with said at least said second fringe in said images of said scattered light and said reference source through said interferometer.

10. A method of remotely sensing a fluid medium as recited in claim 5, further comprising diffusing and expanding an angular diversity of said substantially monochromatic light of said reference source prior to the operation of interleaving said substantially monochromatic light of said reference source with said scattered light.

11. A method of remotely sensing a fluid medium as recited in claim 1, further comprising generating said first beam of substantially monochromatic light and projecting said first beam of substantially monochromatic light into said fluid medium along said first axis.

12. A method of remotely sensing a fluid medium as recited in claim 1, further comprising collimating said scattered light prior to the operation of forming said image of said scattered light through said interferometer.

13. A method of remotely sensing a fluid medium as recited in claim 1, wherein each of said at least said first fringe and said at least said second fringe are arcuately shaped, further comprising azimuthally compressing said at least said first fringe and said at least said second fringe so as to form an associated linear fringe pattern, wherein the operation of detecting at least a portion of said image of said first plurality of fringes comprises detecting at least a portion of said associated linear fringe pattern.

14. A method of remotely sensing a fluid medium as recited in claim 13, wherein the operation of azimuthally compressing said at least said first fringe and said at least said second fringe comprises binning at least a portion of said plurality of detected signals corresponding to said image of said first plurality of fringes so as to generate a corresponding at least one set of detected signals representative of said at least said first fringe and said at least said second fringe.

15. A method of remotely sensing a fluid medium as recited in claim 13, wherein the operation of azimuthally compressing said at least said first and said at least said second fringes is performed with either a circle-to-line interferometer optic or a holographic optical element prior to the operation of detecting at least said portion of said image of said first plurality of fringes.

16. A method of remotely sensing a fluid medium as recited in claim 1, wherein said fluid medium comprises an atmosphere.

17. A method of remotely sensing a fluid medium as recited in claim 1, wherein said at least one measure of said fluid medium associated with at least one of said first or second portions of said fluid medium comprises a velocity of said fluid medium.

18. A method of remotely sensing a fluid medium as recited in claim 1, wherein said at least one measure of said fluid medium associated with at least one of said first or second portions of said fluid medium comprises a temperature of said fluid medium.

19. A method of remotely sensing a fluid medium as recited in claim 1, wherein said at least one measure of said fluid medium associated with at least one of said first or second portions of said fluid medium comprises a density of said fluid medium.

20. A method of remotely sensing a fluid medium as recited in claim 1, further comprising defining a first function comprising a model of an optical response of said interferometer underlying said first plurality of fringes, wherein said first function incorporates at least one parameter responsive to said fluid medium, the operation of detecting said image comprises generating a set of image data responsive to an intensity distribution of said image, at least one of the operations of analyzing said at least said first fringe of said first plurality of fringes or analyzing said at least said second fringe of said first plurality of fringes is in accordance with a function fitting process on corresponding fringe data of either said at least said first fringe of said first plurality of fringes or said at least said second fringe of said first plurality of fringes, corresponding to a corresponding portion of said fluid medium, wherein said function fitting process comprises determining said at least one parameter of said first function associated with said corresponding fringe data so that said first function at least approximates a portion of said set of image data corresponding to said corresponding fringe data, and said at least one measure of said fluid medium within said corresponding portion of said fluid medium is responsive to said at least one parameter associated with said corresponding fringe data.

21. A method of remotely sensing a fluid medium as recited in claim 20, wherein said fluid medium comprises an atmosphere, and said first function is responsive to a number of photons responsive to scattering by aerosols in said atmosphere, a number of photons responsive to scattering by molecules in said atmosphere, a number of photons resulting from background radiation, a magnitude of velocity of said atmosphere and a temperature of said atmosphere.

22. A method of remotely sensing a fluid medium as recited in claim 20, further comprising

a. receiving a portion of said substantially monochromatic light from a source thereof as a reference source;

and

b. detecting said reference source, wherein the operations of analyzing said at least said first fringe of said first plurality of fringes and analyzing said at least said second fringe of said first plurality of fringes are responsive to at least one corresponding reference signal detected from said reference source, wherein said first function comprises at least one term related to at least one defect of said interferometer, further comprising characterizing said at least one term related to said at least one defect responsive to said at least one corresponding reference signal.

23. A method of remotely sensing a fluid medium as recited in claim 1, further comprising

a. defining a first function comprising a model of an optical response of said interferometer underlying said first plurality of fringes, wherein said first function incorporates at least one parameter responsive to said fluid medium,

b. defining at least one second function as a partial derivative of said first function with respect to a corresponding one said at least one parameter, wherein at least one of the sets of operations of detecting and analyzing said at least said first fringe of said first plurality of fringes or detecting and analyzing said at least said second fringe of said first plurality of fringes is in accordance with an integration and solving process on corresponding fringe data of either said at least said first fringe of said first plurality of fringes or said at least said second fringe of said first plurality of fringes, corresponding to a corresponding portion of said fluid medium, wherein said integration and solving process comprises:

i. selectively integrating at least one portion of said corresponding fringe data, wherein said at least one portion of said corresponding fringe data is selected responsive to a value of said at least one second function in relation to a corresponding threshold, wherein said at least one second function corresponds to said corresponding one said at least one parameter, and the operation of selectively integrating said at least one portion of said corresponding fringe data provides for generating a corresponding integrated signal value;

ii. repeating the operation of selectively integrating said at least one portion of said corresponding fringe data for each said at least one parameter to be identified so as to provide for generating a set of integrated signal values, wherein said set of integrated signal values comprises either a set of first and second complementary signals for each said at least one parameter to be identified or a combination of at least one of said first or second complementary signals corresponding to each said corresponding one said at least one parameter and an integrated signal value resulting from an integration of an entirety of said corresponding fringe data, said first complementary signal corresponds to said corresponding integrated signal value for a first portion of said corresponding fringe data for which said at least one second function exceeds a first threshold, and said second complementary signal corresponds to said corresponding integrated signal value for a second portion of said corresponding fringe data for which said at least one second function is less than a second threshold; and

iii. determining said at least one parameter of said first function associated with said corresponding fringe data from said set of integrated signal values, wherein said at least one measure of said fluid medium within said corresponding portion of said fluid medium is responsive to said at least one parameter associated with said corresponding fringe data.

24. A method of remotely sensing a fluid medium as recited in claim 23, wherein said fluid medium comprises an atmosphere, and said first function is responsive to a number of photons responsive to scattering by aerosols in said atmosphere, a number of photons responsive to scattering by molecules in said atmosphere, a number of photons resulting from background radiation, a magnitude of velocity of said atmosphere and a temperature of said atmosphere.

25. A method of remotely sensing a fluid medium as recited in claim 23, wherein said fluid medium comprises an atmosphere, and said first function is of the form I(phi)=A*H(phi,mA)+M*H(phi,mM)+B*T^2/(1−

R^2), wherein I is an intensity of said portion of said image of said first plurality of fringes responsive to phi, phi is a function responsive to one said at least one parameter corresponding to a velocity of said atmosphere and responsive to a radial dimension of said first plurality of fringes, A is one said at least one parameter representative of a number of photons scattered by aerosol particles in said atmosphere, mA is a molecular mass of said aerosol particles, M is one said at least one parameter representative of a number of photons scattered by molecules in said atmosphere, mM is a molecular mass of said molecules, B is one said at least one parameter representative of a number of background photons from said atmosphere, T is a transmissivity associated with said interferometer, R is a reflectivity associated with said interferometer, and H is a function responsive to at least one measure of defects of said interferometer and responsive to one said at least one parameter responsive to a temperature of said atmosphere.

26. A method of remotely sensing a fluid medium as recited in claim 23, further comprising:

a. receiving a portion of said substantially monochromatic light from a source thereof as a reference source; and

b. detecting said reference source, wherein the operations of analyzing said at least said first fringe of said first plurality of fringes and analyzing said at least said second fringe of said first plurality of fringes are responsive to at least one corresponding reference signal detected from said reference source, and said first function comprises at least one term related to at least one defect of said interferometer, further comprising characterizing said at least one term related to said at least one defect responsive to said corresponding reference signal.

27. A method of remotely sensing a fluid medium as recited in claim 23, wherein said first and second thresholds are dependent upon said at least one parameter.

28. A method of remotely sensing a fluid medium as recited in claim 23, wherein the operation of selectively integrating said at least one portion of said corresponding fringe data comprises selectively reflecting at least one portion of light associated with said corresponding fringe data to at least one photodetector, wherein said at least one photodetector generates said corresponding integrated signal value.

29. A method of remotely sensing a fluid medium as recited in claim 28, wherein the operation of selectively reflecting said at least one portion of light associated with said corresponding fringe data to said at least one photodetector comprises reflecting a first disjoint portion of said at least one portion of light associated with said corresponding fringe data to a first photodetector to generate said first complementary signal and reflecting a second disjoint portion of said at least one portion of light associated with said corresponding fringe data to a second photodetector to generate said second complementary signal.

30. A method of remotely sensing a fluid medium as recited in claim 28, wherein the operation of selectively reflecting said at least one portion of light associated with said corresponding fringe data to said at least one photodetector comprises reflecting one of a first and second disjoint portion of said at least one portion of light associated with said corresponding fringe data to a common one said at least one photodetector so as to provide for generating a corresponding either said first complementary signal or said second complementary signal.

31. A method of remotely sensing a fluid medium as recited in claim 11, wherein said fluid medium comprises an atmosphere, and the operations of generating said first beam of substantially monochromatic light and receiving said scattered light from said portion of said atmosphere are performed from an air vehicle, and said at least one measure of said atmosphere within each of said first and second portions of said atmosphere provides for generating air data used for controlling said air vehicle.

32. A method of remotely sensing a fluid medium as recited in claim 11, wherein said fluid medium comprises an atmosphere, and the operations of generating said first beam of substantially monochromatic light and receiving said scattered light from said portion of said atmosphere are performed from an air vehicle, and said at least one measure of said atmosphere within each of said first and second portions of said atmosphere provides for monitoring said atmosphere.

33. A method of remotely sensing a fluid medium as recited in claim 11, wherein said fluid medium comprises an atmosphere, and the operations of generating said first beam of substantially monochromatic light and receiving said scattered light from said portion of said atmosphere are performed from at least one of a housing of a wind turbine or a central axis of a rotating portion of said wind turbine, and said at least one measure of said atmosphere within each of said first and second portions of said atmosphere provides for controlling said wind turbine.

34. A method of remotely sensing a fluid medium as recited in claim 11, wherein said fluid medium comprises an atmosphere, and the operations of generating said first beam of substantially monochromatic light and receiving said scattered light from said portion of said atmosphere are performed from a ground station, and said at least one measure of said atmosphere within each of said first and second portions of said atmosphere provides monitoring or predicting at least one weather condition in said atmosphere.

35. A system for remotely sensing a fluid medium, comprising:

a. a first beam of substantially monochromatic light projected into the fluid medium along a first axis;

b. an interferometer configured to receive scattered light of said first beam of substantially monochromatic light from said fluid medium along a portion of said first beam of substantially monochromatic light;

c. a set of imaging optics that comprises an optic axis along which said scattered light is received, said set of imaging optics is operatively associated with or a part of said interferometer, said set of imaging optics provides for generating an image of a first plurality of fringes from said interferometer responsive to said scattered light, wherein said image of said first plurality of fringes is located at a focal plane of said set of imaging optics, and said optic axis is oriented in a different direction relative to said first axis;

d. at least one detector operatively associated with said set of imaging optics, wherein said at least one detector provides for detecting said image of said first plurality of fringes, and different fringes of said first plurality of fringes are associated with different portions of said fluid medium along said portion of said first beam of substantially monochromatic light; and

e. a processor operatively coupled to said at least one detector, wherein said processor provides for determining at least one measure of said fluid medium within a first portion of said fluid medium responsive to a detection of a first fringe of said image of said first plurality of fringes by said at least one detector, and said processor provides for determining at least one measure of said fluid medium within a second portion of said fluid medium responsive to a detection of a second fringe of said image of said first plurality of fringes by said at least one detector.

36. A system for remotely sensing a fluid medium as recited in claim 35, wherein said first beam of substantially monochromatic light comprises ultraviolet light.

37. A system for remotely sensing a fluid medium as recited in claim 35, further comprising a light source to generate said first beam of substantially monochromatic light.

38. A system for remotely sensing a fluid medium as recited in claim 37, wherein said light source comprises a laser.

39. A system for remotely sensing a fluid medium as recited in claim 37, further comprising a filter in cooperation with said light source so as to provide for said first beam of substantially monochromatic light projected into said fluid medium to be substantially monochromatic.

40. A system for remotely sensing a fluid medium as recited in claim 35, further comprising a pulsed laser light source to generate said first beam of substantially monochromatic light, wherein said processor is synchronized with said pulsed laser light source so as to provide for acquiring both a reference signal and at least one scattered light signal from said at least one detector.

41. A system for remotely sensing a fluid medium as recited in claim 35, wherein said interferometer comprises a Fabry-Perot etalon in cooperation with said set of imaging optics, said set of imaging optics are located between said Fabry-Perot etalon and an operative surface of an associated detection system, said detection system comprises said at least one detector, and said Fabry-Perot etalon comprises a plurality of partially reflective surfaces separated by a gap, and a size of said gap is controllable responsive to said processor.

42. A system for remotely sensing a fluid medium as recited in claim 35, wherein said interferometer comprises a Fabry-Perot etalon in cooperation with said set of imaging optics, said set of imaging optics are located between said Fabry-Perot etalon and an operative surface of an associated detection system, and said detection system comprises said at least one detector.

43. A system for remotely sensing a fluid medium as recited in claim 42, further comprising a collimating lens operatively associated with said interferometer and located so that said scattered light receive by said interferometer is first received by said collimating lens.

44. A system for remotely sensing a fluid medium as recited in claim 43, further comprising:

a. a first beam splitter optic configured to receive said first beam of substantially monochromatic light prior to an interaction thereof with said fluid medium, wherein said first beam splitter optic provides for generating a reference source of said substantially monochromatic light from a portion of said first beam of substantially monochromatic light; and

b. a fiber optic, wherein said substantially monochromatic light of said reference source is directed through said fiber optic to a focal plane of said collimating lens, and through said collimating lens to said interferometer, and said set of imaging optics provides for generating an image of a second plurality of fringes from said interferometer responsive to said substantially monochromatic light of said reference source, wherein said image of said second plurality of fringes is located at said focal plane of said set of imaging optics.

45. A system for remotely sensing a fluid medium as recited in claim 35, further comprising a bandpass filter in cooperation with said interferometer.

46. A system for remotely sensing a fluid medium as recited in claim 35, wherein said at least one detector comprises an imager having an operative surface substantially coincident with said image from said interferometer, and said imager provides for generating an electronic signal representative of said image.

47. A system for remotely sensing a fluid medium as recited in claim 46, wherein said imager comprises a CCD camera, and said electronic signal generated by said CCD camera comprises a pixilated representation of said image.

48. A system for remotely sensing a fluid medium as recited in claim 35, wherein said at least one detector comprises at least one photodetector of an associated detection system, and said detection system further comprises a digital micromirror device (DMD), wherein said digital micromirror device (DMD) comprises a plurality of micromirrors, each micromirror of said plurality of micromirrors comprises a reflective surface, the plurality of micromirrors comprising a plurality of reflective surfaces that are located substantially coincident with said image from said interferometer, each micromirror is positionable into any of a plurality of pixel-mirror rotational states, said digital micromirror device (DMD) is configured in relation to said at least one detector so that each said micromirror of said plurality of micromirrors in at least one of said plurality of pixel-minor rotational states provides for reflecting light of said image to a corresponding one said at least one photodetector.

49. A system for remotely sensing a fluid medium as recited in claim 48, further comprising a light block, wherein said plurality of pixel-mirror rotational states comprises at least two pixel-minor rotational states, each said micromirror of said plurality of micromirrors in a first of said plurality of pixel-mirror rotational states provides for reflecting light of said image to said corresponding one said at least one photodetector, and each said micromirror of said plurality of micromirrors in a second of said plurality of pixel-mirror rotational states provides for reflecting light of said image to said light block.

50. A system for remotely sensing a fluid medium as recited in claim 49, wherein said plurality of pixel-mirror rotational states comprises at least three pixel-mirror rotational states, and each said micromirror of said plurality of micromirrors in a third of said plurality of pixel-mirror rotational states provides for reflecting light of said image to another said at least one photodetector.

51. A system for remotely sensing a fluid medium as recited in claim 35, further comprising a first beam splitter optic configured to receive said first beam of substantially monochromatic light prior to an interaction thereof with said fluid medium, wherein said first beam splitter optic provides for generating a reference source of said substantially monochromatic light from a portion of said first beam of substantially monochromatic light, said substantially monochromatic light of said reference source is separately detected by said at least one detector so as to provide at least one associated reference signal that is used in cooperation with the detection of said different fringes of said first plurality of fringes associated with said different portions of said fluid medium.

52. A system for remotely sensing a fluid medium as recited in claim 51, wherein said substantially monochromatic light of said reference source is detected by a separate said at least one detector, wherein said separate said at least one detector comprises a photodetector that provides for detecting an intensity of said substantially monochromatic light of said reference source.

53. A system for remotely sensing a fluid medium as recited in claim 51, wherein said substantially monochromatic light of said reference source is directed through said interferometer prior to the separate detection by said at least one detector, and said set of imaging optics provides for generating an image of a second plurality of fringes from said interferometer responsive to said substantially monochromatic light of said reference source, wherein said image of said second plurality of fringes is located at said focal plane of said set of imaging optics.

54. A system for remotely sensing a fluid medium as recited in claim 53, further comprising a second beam splitter optic, wherein said second beam splitter optic provides for combining said substantially monochromatic light of said reference source with said scattered light of said first beam of substantially monochromatic light so as to form a combined light signal received by said interferometer.

55. A system for remotely sensing a fluid medium as recited in claim 54, wherein said substantially monochromatic light of said reference source is reflected by a partially reflective surface of said second beam splitter optic.

56. A system for remotely sensing a fluid medium as recited in claim 54, wherein said substantially monochromatic light of said reference source is transmitted through a partially reflective surface of said second beam splitter optic.

57. A system for remotely sensing a fluid medium as recited in claim 53, wherein said image of said first plurality of fringes is separated from said image of said second plurality of fringes.

58. A system for remotely sensing a fluid medium as recited in claim 54, wherein said image of said first plurality of fringes is interleaved with said image of said second plurality of fringes.

59. A system for remotely sensing a fluid medium as recited in claim 58, further comprising a first mask interposed between said reference source and said second beam splitter optic, wherein said first mask is shaped so as to block said second plurality of fringes from more than insubstantially overlapping said first plurality of fringes.

60. A system for remotely sensing a fluid medium as recited in claim 59, wherein said first mask comprises at least one opaque region on an otherwise transparent element located between said reference source and said second beam splitter optic.

61. A system for remotely sensing a fluid medium as recited in claim 59, further comprising a second mask interposed between said fluid medium and said second beam splitter optic, wherein said second mask is shaped so as to block said first plurality of fringes from more than insubstantially overlapping said second plurality of fringes.

62. A system for remotely sensing a fluid medium as recited in claim 59, wherein said first mask comprises a digital micromirror device (DMD) located between said reference source and said second beam splitter optic, wherein a plurality of micromirrors of said digital micromirror device (DMD) are set to a first pixel-mirror rotational state so as to provide for reflecting said substantially monochromatic light of said reference source towards said second beam splitter optic, and a remainder of said micromirrors of said digital micromirror device (DMD) illuminated by said reference source are set to another pixel-mirror rotational state so as to reflect light impinging thereon away from said second beam splitter optic.

63. A system for remotely sensing a fluid medium as recited in claim 58, wherein said first beam of substantially monochromatic light is pulsed, and a detection by said at least one detector is timed in relation to a pulsing of said first beam of said substantially monochromatic light so as to provide for said at least one detector to detect said second plurality of fringes prior to detecting said first plurality of fringes.

64. A system for remotely sensing a fluid medium as recited in claim 58, wherein said reference source further comprises a rotating diffuser in cooperation with an integrating sphere, said substantially monochromatic light of said reference source from said first beam splitter optic is directed into said integrating sphere and reflected from an internal surface thereof, and said substantially monochromatic light of said reference source from said first beam splitter optic is transmitted through said rotating diffuser.

65. A system for remotely sensing a fluid medium as recited in claim 35, wherein said plurality of different scattered light signals are processed by a common said interferometer that provides for generation a plurality of sets of said first plurality of fringes.

66. A system for remotely sensing a fluid medium as recited in claim 65, further comprising a pyramidal reflector comprising a plurality of different reflective surfaces, each of said plurality of different reflective surfaces on different sides of said pyramidal reflector, wherein each reflective surface of said plurality of different reflective surfaces reflects a different scattered light signal of different said scattered light toward said interferometer so as to provide for generating a different set of said plurality of sets of said plurality of fringes.

67. A system for remotely sensing a fluid medium as recited in claim 35, further comprising a set of receiver optics operatively positioned with said set of imaging optics, wherein said set of receiver optics and said set of imaging optics comprise an optic axis along which said scattered light is received, said set of receiver optics is operative between said interferometer and said portion of said first beam of substantially monochromatic light.

68. A system for remotely sensing a fluid medium as recited in claim 67, wherein said set of receiver optics is located so that said scattered light receive by said interferometer is first received by said set of receiver optics.

69. A system for remotely sensing a fluid medium as recited in claim 67, further comprising a collimating lens operatively associated with said interferometer and located so that said scattered light receive by said interferometer is first received by said collimating lens, wherein said set of receiver optics is located so that said scattered light receive by said interferometer is first received by said set of receiver optics, said set of receiver optics and said collimating lens are configured in relation to one another so as to provide for an intermediate image plane therebetween, said set of receiver optics is configured to form an intermediate image of said scattered light in said intermediate image plane, and said collimating lens in cooperation with said set of imaging optics is configured to form an image of said intermediate image in said focal plane of said set of imaging optics substantially coincident with said operative surface of said detection system.

70. A system for remotely sensing a fluid medium as recited in claim 69, wherein said set of receiver optics are configured in relation to said collimating lens so as to satisfy a Scheimpflug condition in respect of said intermediate image plane.

71. A system for remotely sensing a fluid medium as recited in claim 67, further comprising a plurality of sets of receiver optics that provide for receiving a plurality of different scattered light signals from a plurality of different regions of said fluid medium, each of said plurality of different scattered light signals comprising different said scattered light, wherein each set of receiver optics of said plurality of sets of receiver optics is oriented in a different direction relative to an axis of a corresponding beam of substantially monochromatic light from which a corresponding scattered light signal of said plurality of different scattered light signals is generated.

72. A system for remotely sensing a fluid medium as recited in claim 71, further comprising at least a second beam of substantially monochromatic light projected into said fluid medium along a corresponding axis, wherein at least a first set of receiver optics oriented in a different direction relative to said first beam of substantially monochromatic light is configured to receive scattered light from a portion of said fluid medium illuminated by said first beam of substantially monochromatic light;

and at least a second set of receiver optics oriented in a different direction relative to said at least said second beam of substantially monochromatic light is configured to receive said scattered light from said fluid medium originating with said at least said second beam of substantially monochromatic light.

73. A system for remotely sensing a fluid medium as recited in claim 71, wherein at least two different sets of receiver optics of said plurality of sets of receiver optics are configured to receive said scattered light from a common region of said fluid medium, and each of said at least two different sets of receiver optics is oriented in a different direction relative to a corresponding said beam of substantially monochromatic light illuminating said common region of said fluid medium.