Combined laser/FLIR optics system

• US 6,359,681 B1
• Filed: 08/09/2000
• Issued: 03/19/2002
• Est. Priority Date: 04/01/1996
• Status: Expired due to Term

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Hill, Timothy A., Tener, Gene D., Bauer, Helmuth, Booth, John R., Donahue, John J., Cole, Jeffrey L., Schildwachter, Eric F., Robertson, Ward D., Jesse, Susan J., Newberg, G. Edward, Pearson, William A., Housand, Brien J., Montgomery, Harvey J., Patel, Bhikhubbai L., Weaver, John F.
• Primary Examiner(s): Buczinski, Stephen C.
• Application Number:
  US09/463,410
• Time in Patent Office: 587 Days
• Field of Search: 356/4.01, 356/141.3, 356/141.1, 356/153, 250/332, 250/342, 250/201.7, 359/558, 359/568, 359/601, 348/353, 348/354, 348/572, 348/574, 348/607, 348/576, 348/205, 348/241, 348/242, 348/252, 348/625, 348/144, 348/164, 318/638, 361/23, 324/522
• US Class Current: 356/4.01
• CPC Class Codes: G01S 17/86 Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders
• CPC Class Codes: G01S 17/87 Combinations of systems using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 7/481 Constructional features, e.g. arrangements of optical elements
• CPC Class Codes: G01S 7/4811 common to transmitter and receiver
• CPC Class Codes: G01S 7/4812 transmitted and received beams following a coaxial path
• CPC Class Codes: G01S 7/4813 Housing arrangements
• CPC Class Codes: G01S 7/4817 relating to scanning
• CPC Class Codes: G01S 7/486 Receivers
• CPC Class Codes: G01S 7/497 Means for monitoring or calibrating
• CPC Class Codes: G01S 7/4972 Alignment of sensor
• CPC Class Codes: G02B 13/14 for use with infrared or ultraviolet radiation G02B13/008, G02B13/16 take precedence
• CPC Class Codes: G02B 15/02 by changing, adding, or subtracting a part of the objective, e.g. convertible objective
• CPC Class Codes: G02B 23/00 Telescopes, e.g. binoculars; Periscopes; Instruments for viewing the inside of hollow bodies; Viewfinders; Optical aiming or sighting devices
• CPC Class Codes: G02B 23/12 with means for image conversion or intensification
• CPC Class Codes: G02B 27/642 Optical derotators, i.e. systems for compensating for image rotation, e.g. using rotating prisms, mirrors
• CPC Class Codes: G02B 27/644 compensating for large deviations, e.g. maintaining a fixed line of sight while a vehicle on which the system is mounted changes course
• CPC Class Codes: G06T 3/14 Transformations for image registration, e.g. adjusting or mapping for alignment of images

Abstract

In a FLIR/laser based targeting and imaging system, the ability to recognize, detect, locate, and/or track targets in an area of interest is significantly improved by reducing the fixed and dynamic alignment errors between the IR LOS and the laser LOS. Fixed alignment errors are reduced with an improved internal boresight module and corresponding boresight method. Dynamic alignment errors are reduced with an opto-electric subsystem that employs a single pitch bearing and a common pitch/yaw afocal for both the laser energy and the IR energy. A segmented window in the system housing includes a circular EMI grid pattern which significantly reduces the amount of off-axis EMI entering the optical pathways, and improved signal processing techniques are employed to enhance the quality of the IR image after the image has been digitized.

Claims

1. A targeting and imaging system comprising:

a forward-looking infrared (FLIR) optical subsystem for receiving infrared (IR) energy from an area of interest (AOI), and for generating an IR image of the AOI; and

a laser optical subsystem for generating laser energy for illuminating at least one object in the AOI and for receiving laser energy reflected by said at least one object;

wherein the laser optical subsystem and the FLIR optical subsystem share a common pitch bearing.

2. A targeting and imaging system in accordance with claim 1, wherein said laser optical subsystem comprises:

a laser transmitter; and

a laser receiver which receives said laser energy reflected by said at least one object.

3. A targeting and imaging system in accordance with claim 2, wherein the laser transmitter is a ND:

YAG laser transmitter.

4. A targeting and imaging system in accordance with claim 2, wherein the laser receiver comprises;

a laser range receiver; and

a laser spot tracker.

5. A targeting and imaging system in accordance with claim 2, wherein the laser transmitter transmits mid-wave IR signals.

6. A targeting and imaging system comprising:

a forward-looking infrared (FLIR) optical system for receiving infrared (IR) energy from an area of interest (AOI);

a FLIR optical imager for generating an IR image with the IR energy received from the AOI, wherein said FLIR optical imager is arranged to receive said IR energy from the FLIR optical system;

a laser transmitter;

a laser receiver; and

laser optics for directing laser energy from said laser transmitter to a desired target located in the AOI, and for directing laser energy returning from the desired target in the AOI to said laser receiver,

wherein said FLIR optical system and said laser optics share a common pitch bearing, such that all optical elements individually subject to pitch rotations are commonly shared by said FLIR optical system and said laser optics.

7. A targeting and imaging system in accordance with claim 6, wherein the optical elements shared by said FLIR optical system and said laser optics means include:

deroll means for optically stabilizing the optical image about the roll axis in response to FLIR energy line-of-sight, pitch angle perturbations.

8. A targeting and imaging system in accordance with claim 7, wherein the optical elements commonly shared by said FLIR optical system and said laser optics further include:

a pitch/yaw afocal; and

a fast steering mirror (FSM).

9. A targeting and imaging system in accordance with claim 7, wherein said deroll means comprises:

a deroll prism.

10. A targeting and imaging system in accordance with claim 6, wherein said FLIR optical system comprises:

a pitch/yaw afocal comprising a plurality of lenses which serve as a common aperture for both the laser energy and the IR energy;

a FLIR field of view (FOV) system which is switchable between a FLIR narrow field of view (NFOV) and a FLIR wide field of view (WFOV), wherein said FLIR FOV system is optically coupled to the pitch/yaw afocal;

a deroll prism; and

a fast steering mirror (FSM).

11. A targeting and imaging system in accordance with claim 10, wherein said FLIR FOV system comprises:

optics which maintains a real entrance pupil and a real exit pupil in an intermediate focal plane.

12. A targeting and imaging system in accordance with claim 6, further comprises:

a FLIR focus assembly for focusing the IR image, said FLIR imager being optically coupled to said FLIR optical system and said FLIR optical imager; and

a FLIR detector which generates an electronic representation of the IR image, said FLIR detector being optically coupled to said FLIR imager through a FLIR imager/detector interface.

13. A targeting and imaging system in accordance with claim 12, wherein said FLIR imager and said FLIR detector each contain a collimating lens for collimating the IR energy that passes through the FLIR imager/detector interface.

14. A targeting and imaging system in accordance with claim 12, wherein said FLIR detector comprises:

a staring focal plane array;

a cooling assembly; and

an atmospheric absorption band, notch filter.

15. A targeting and imaging system in accordance with claim 6, wherein said laser optics comprise:

a pitch/yaw afocal;

laser focus optics which focuses the laser energy, said laser focus optics being optically coupled to the pitch/yaw afocal;

combined optics for directing the laser energy into said laser receiver, said combined optics being optically coupled to said laser focus optics;

a deroll prism;

a fast steering mirror (FSM); and

a compensator which steers the laser energy and adjusts the polarization of the laser energy, said compensator being connected to said combined optics through said deroll prism and said FSM, and connected to said laser transmitter.

16. A targeting and imaging system in accordance with claim 15, wherein said laser receiver comprises:

a laser range receiver (LRR); and

a laser spot tracker (LST).

17. A targeting and imaging system in accordance with claim 16, wherein said combined optics means comprises:

means for steering the laser energy inside said combined optics means; and

an LST/LRR switch means for directing laser energy into one of the LRR and the LST.

18. A targeting and imaging system in accordance with claim 17, wherein said means for steering the laser energy inside said combined optics means comprises:

a pair of Risley prisms.

19. A targeting and imaging system in accordance with claim 17, wherein said LRR/LST switch means comprises:

an optical waveplate.

20. A targeting and imaging system in accordance with claim 15, wherein said compensator means comprises:

a pair of optical waveplates for adjusting the polarization of the laser energy to ensure that a sufficient amount of laser energy passes through the deroll prism; and

a pair of Risley prisms for steering the laser energy.

21. A targeting and imaging system in accordance with claim 6, wherein said laser optics means comprises:

a pitch/yaw afocal;

laser focusing optics which focus the laser energy, said laser focusing optics being optically coupled to the pitch/yaw afocal;

means for reflecting the laser energy into said laser receiver means from said laser focus means;

a deroll prism optically coupled to said means for reflecting laser energy into said laser receiver means;

a fast steering mirror (FSM) optically coupled to said deroll prism; and

a compensator which steers the laser energy and adjusts the polarization of the laser energy, said compensator being connected to said FSM and to said laser transmitter.

22. A targeting and imaging system in accordance with claim 21, wherein said laser receiver comprises:

a combined laser range receiver (LRR)/laser spot tracker(LST).

23. A targeting and imaging system in accordance with claim 22, wherein said LRR is a pin diode;

wherein said LST is a quad-cell receiver; and

wherein said LRR and said LST are combined into a single unit, such that said LRR is located at the center of said LST.

24. A targeting and imaging system in accordance with claim 21, wherein said compensator comprises:

a pair of optical waveplates which adjust the polarization of the laser energy to control an amount of laser energy passes through the deroll prism; and

a pair of Risley prisms for steering the laser energy.

25. A targeting and imaging system comprising:

forward-looking infrared (FLIR) optics for steering an infrared (IR) line-of-sight (LOS) towards a desired area of interest (AOI), for receiving IR energy from the AOI, for focusing the IR energy, and for generating an optical image of the AOI;

a laser transmitter;

a laser range receiver (LRR);

a laser spot tracker (LST); and

laser optics means for steering a laser LOS, such that the transmitter laser energy illuminates at least a portion of the AOI, for receiving laser energy, and for directing the received laser energy into the LRR and the LST,

wherein said FLIR optics means and said laser optics means share a single pitch bearing, and

wherein the IR energy and the laser energy pass through a common aperture.

26. A targeting and imaging system in accordance with claim 25, further comprising:

LOS correction means for adjusting the IR LOS and the laser LOS, and for minimizing dynamic LOS alignment errors between the IR LOS and the laser.

27. A targeting and imaging system in accordance with claim 25, wherein said LOS correction means comprises:

optical elements that are shared by said FLIR optics and said laser optics, wherein each of said shared optical elements is individually subject to pitch axis rotations.

28. A targeting and imaging system in accordance with claim 27, wherein the shared optical elements include:

a pitch/yaw afocal;

a deroll prism for optically stabilizing the IR image about the roll axis in response to FLIR LOS pitch angle perturbations; and

a fast steering mirror (FSM) that reduces high frequency vibrations in the IR LOS and the laser LOS.

29. A targeting and imaging system in accordance with claim 26, wherein said LOS correction means comprises:

a plurality of gimbal assemblies;

a deroll prism that for optically stabilizing the IR image about the roll axis in response to FLIR LOS pitch angle perturbations;

a fast steering mirror that reduces high frequency vibrations in the IR LOS and the laser LOS; and

vibration isolation means for attenuating high frequency vibrations and structural bending forces.

30. A targeting and imaging system in accordance with claim 29, wherein said vibration isolation means is a passive, optical isolation bed.

31. A targeting and imaging system in accordance with claim 25, further comprising fault isolation means for isolating an electrical fault in a servo system comprising a servo motor and an amplifier, said fault isolation means comprises:

first means for driving current in a first direction through a winding in the servo motor;

second means for driving current in a second direction through the winding in the servo motor; and

means for isolating a fault between the amplifier and the servo motor as a function of an amount of current flowing into said first and said second means for driving current, and as a function of the current flowing out of said first and said second means for driving current.

32. A targeting and imaging system in accordance with claim 31, wherein said fault isolation means further comprises:

a first and a second means for each winding in the servo motor.

33. A targeting and imaging system in accordance with claim 32, wherein the servo motor is a dual-phase torque motor, and the amplifier is a pulse-width modulated amplifier.

34. A targeting and imaging system in accordance with claim 32, wherein the servo motor is a three-phase torque motor, and the amplifier is a pulse-width modulated amplifier.

35. A targeting and imaging system in accordance with claim 32, wherein the servo motor is a single phase torque motor, and the amplifier is a linear amplifier.

36. A targeting and imaging system in accordance with claim 31, wherein said means for isolating a fault between the amplifier and the servo motor as a function of the amount of current flowing into said first and second means, and as a function of the current flowing out of said first and second means comprises:

a first input resistor connected between a voltage source and said first means;

a second input resistor connected between the voltage source and said second means; and

an output resistor connected between said first and second means and ground.

37. A targeting and imaging system in accordance with claim 36, wherein said fault isolation means further comprises:

a first and a second means for each winding in the servo motor.

38. A targeting and imaging system in accordance with claim 31, wherein:

said first means for driving current in a first direction through the winding in the servo motor comprises;

a first linear amplifier connected to a first end of the winding,

a first return current sensing resistor connected between said first linear amplifier and ground,

a second linear amplifier connected to a second end of the winding,

a second return current sensing resistor connected between said second linear amplifier and ground,

a shunt resistor connected in parallel with the winding,

a voltage source connected to the input of the first and the second linear amplifiers through a supply current sensing resistor, and

control circuit means for biasing the first linear amplifier and the second linear amplifier such that the first linear amplifier produces a differential voltage output with respect to the second linear amplifier.

39. A targeting and imaging system in accordance with claim 31, wherein:

said second means for driving current in a second direction through the winding in the servo motor comprises;

the first linear amplifier connected to the first end of the winding,

the first return current sensing resistor between said first linear amplifier and ground,

the second linear amplifier connected to a second end of the winding,

the second return current sensing resistor between said second linear amplifier and ground,

the voltage source connected to the input of the first and the second linear amplifiers through the supply current sensing resistor, and

control circuit means for biasing the first linear amplifier and the second linear amplifier such that the second linear amplifier produces a higher voltage output than the first linear amplifier.

40. A targeting and imaging system in accordance with claim 31, wherein:

said means for isolating a fault between the amplifier and the servo motor as a function of the amount of current flowing into said first and second means, and as a function of the current flowing out of said first and second means comprises;

supply current sensing means for determining a voltage proportional to the amount of current flowing through the supply current sensing resistor, and

return current sensing means for determining a voltage proportional to the amount of current flowing through the first and the second return current resistors.

41. A targeting and imaging system in accordance with claim 38, wherein said supply current sensing means comprises:

a current sensing amplifier.

42. A targeting and imaging system in accordance with claim 38, wherein said return current sensing means comprises:

a current sensing amplifier.

43. A targeting and imaging system in accordance with claim 25, further comprising a boresight subsystem that includes:

means for projecting IR energy through a reticle pattern onto a focal plane array;

means for aligning the IR LOS with a plurality of IR openings in the reticle pattern;

means for receiving laser energy passing into the boresight subsystem through a laser opening in the reticle pattern, wherein the laser opening has lateral edges that project radially inward toward the centrally located opening;

means for translating the laser LOS toward the centrally located opening along a lateral edge;

means for translating the laser LOS in accordance with a number of grid positions; and

means for aligning the laser LOS in accordance with the grid position that corresponds with a peak laser energy detection by said means for receiving laser energy.

44. A targeting and imaging system in accordance with claim 25, further comprising a signal processing subsystem that includes an analog-to-digital converter for converting the optical image into a digital image.

45. A targeting and imaging system in accordance with claim 44, wherein said signal processing subsystem includes a two-dimensional (2D) sharpen filter comprising:

means for extracting a low frequency digital image from the digital image;

means for extracting a high frequency digital image from the digital image;

means for adjusting a relative gain between the low frequency digital image and the high frequency digital image to produce an adjusted low frequency digital image and an adjusted high frequency digital image; and

means for combining the adjusted low frequency digital image and the adjusted high frequency digital image.

46. A targeting and imaging system in accordance with claim 45, wherein said 2D sharpen filter further comprises:

means for measuring a contrast value for the digital image, wherein the relative gain is adjusted as a function of said contrast value.

47. A targeting and imaging system in accordance with claim 46, wherein said means for measuring a contrast value comprises:

means for determining a difference between digital values corresponding to neighboring pixels in the digital image; and

means for summing the difference values.

48. A targeting and imaging system in accordance with claim 45, wherein said means for extracting a low frequency digital image comprises:

means for averaging each pixel value in the digital image with a plurality of pixel values for neighboring pixels.

49. A targeting and imaging system in accordance with claim 44, wherein said analog-to-digital conversion means comprises a number “

n”

of analog-to-digital converters (ADCs), and wherein said signal processing subsystem includes an ADC offset pattern removal means comprising;

means for generating “

n”

histograms, wherein each of said n histograms reflects a dynamic range of pixel values produced by a corresponding one of said “

n”

ADCs;

means for adjusting a pixel offset coefficient for each pixel associated with the corresponding one of said “

n”

ADCs as a function of the dynamic range of the corresponding histogram; and

means for removing ADC offset pattern differences by adjusting the value of each pixel associated with the corresponding one of said “

n”

ADCs as a function of the corresponding, adjusted pixel offset coefficient.

50. A targeting and imaging system in accordance with claim 44, wherein said signal processing subsystem includes a subpixel dither means comprising:

means for horizontally shifting a portion of the IR image by an amount equal to a fraction of a pixel size;

means for generating a first video field by integrating the portion of the IR image with the horizontally shifted portion of the IR image;

means for vertically shifting the desired portion of the IR image by the same fraction of a pixel size;

means for horizontally shifting the vertically shifted portion of the IR image by the same fraction of a pixel size;

means for generating a second video field by integrating the vertically shifted portion of the IR image with the vertically and horizontally shifted portion of the IR image; and

means for electronically interleaving the first image field and the second image field.

51. A targeting and imaging system in accordance with claim 50, wherein said means for horizontally and vertically shifting the desired portion of the IR image comprises a fast steering mirror.

52. A targeting and imaging system in accordance with claim 44, wherein said signal processing subsystem includes means for focusing an IR image comprising:

means for adjusting an optical focusing element a plurality of times;

an array of IR detector elements;

optics means for illuminating the array of IR detector elements with a high frequency test pattern after each adjustment of the optical focusing element, wherein a random phase relationship exists between said test pattern and said array of IR detector elements, and wherein said analog-to-digital converter converts an analog value associated with each of said detector elements to a corresponding digital word;

means for generating a peak contrast measure based on the digital words after each adjustment of the optical focusing element; and

control means for generating a control signal which controls said means for focusing the optical focusing element, said control means being responsive to said means for generating a peak contrast measure.

53. A targeting and imaging system in accordance with claim 52, wherein said means for illuminating illuminates said array of IR detector elements high frequency test pattern which is a checkerboard pattern comprising an array of alternatively dark and light squares.

54. A targeting and imaging system in accordance with claim 52, wherein said means for generating a peak contrast measure comprises:

means for generating a best fit polynomial curve connecting the contrast measures.

55. A targeting and imaging system in accordance with claim 25, further comprising:

a housing assembly; and

a window associated with said housing assembly, through which IR energy and laser energy pass.

56. A targeting and imaging system in accordance with claim 55, wherein said window comprises a plurality of window panels angularly offset from one another.

57. A targeting and imaging system in accordance with claim 56, wherein each of said window panels comprises:

an electromagnetic interference coating.

58. A targeting and imaging system in accordance with claim 56, wherein each of said window panels comprises:

a rain erosion protection coating.

59. A targeting and imaging system in accordance with claim 56, wherein each of said window panels comprises:

a durable antireflection (DAR) coating.

60. A targeting and imaging system in accordance with claim 56, wherein each of said window panels comprises:

an interior anti-reflection coating.

61. A targeting and imaging system in accordance with claim 55, wherein said window comprises:

is an electro-magnetic interference (EMI) grid.

62. A targeting and imaging system in accordance with claim 61, wherein said EMI grid comprises:

an array of circular grid elements, and wherein said circular elements are aligned in rows and columns such that on-axis electro-magnetic radiation is permitted to pass through the grid, and off-axis electro-magnetic radiation is radially diffracted.

63. A method of isolating an electrical fault in a servo system comprising a servo motor, said method comprising the steps of:

(a) generating a first current activation signal;

(b) activating a first current control means for conducting current in a first direction through a winding in the servo motor in response to the first current activation signal independent of servo motor shaft position;

(c) generating a second current activation signal;

(d) activating a second current control means for conducting current in a second direction through the winding in the servo motor in response to the second current activation signal independent of servo motor shaft position; and

(e) determining whether a fault exists as a function of an amount of current flowing into and out of the first and the second current control means.

64. A method in accordance with claim 63, wherein the servo motor is a dual-phase motor, and the first and the second current control means are pulse-width modulated amplifiers.

65. A method in accordance with claim 63, wherein the servo motor is a three-phase motor, and the first and the second current control means are pulse-width modulated amplifiers.

66. A method in accordance with claim 63, wherein the servo motor is a single-phase motor, and the first and the second current control means are linear amplifiers.

67. A method in accordance with claim 63, wherein step (e) it is determined whether one of a motor winding short circuit, a motor winding short-to-ground, a motor winding open circuit, an amplifier short circuit, or an amplifier open circuit exists.

68. A method of isolating an electrical fault in a servo system comprising a servo motor and an amplifier, said method comprises the steps of:

(a) generating a first current command;

(b) activating a current control means for conducting current in a first direction through a motor winding in response to the first current command independent of servo motor shaft position;

(c) determining whether an amount of current flowing into the first current control means is greater than a predefined threshold;

(d) determining whether the amount of current flowing out of the first current control means is zero;

(e) generating a second current command;

(f) activating a second current control means for conducting current in a second direction through the motor winding in response to the second current command independent of servo motor shaft position;

(g) determining whether an amount of current flowing into the second current control means is greater than the predefined threshold;

(h) determining whether the amount of current flowing out of the second current control means is zero;

(i) determining whether an electrical fault has occurred in the amplifier or whether an electrical fault has occurred in the motor winding as a function of the amount of current flowing into and out of the first and the second current control means.

69. A method in accordance with claim 68, wherein said step of determining whether an electrical fault has occurred comprises:

determining the fault to be a motor winding short circuit fault if;

the amount of current flowing into said means for conducting first current is greater than the predefined threshold, and

the amount of current flowing into said means for conducting second current is greater than the predefined threshold.

70. A method in accordance with claim 68, wherein said step of determining whether an electrical fault has occurred comprises:

determining the fault to be a motor winding short-to-ground fault if;

the amount of current flowing into said means for conducting first current is greater than the predefined threshold, and

the amount of current flowing into said means for conducting second current is zero.

71. A method in accordance with claim 68, wherein said step of determining whether an electrical fault has occurred comprises:

determining the fault to be an amplifier short circuit fault if;

the amount of current flowing into said means for conducting first current is greater than the predefined threshold, or

the amount of current flowing into said means for conducting second current is greater than the predefined threshold,

but not if both are greater than the predefined threshold.

72. A method in accordance with claim 68, wherein said steps of determining whether an electrical fault has occurred comprises:

determining the fault to be a motor winding open circuit fault if;

the amount of current flowing into said means for conducting first current is not greater than the predefined threshold, and

the amount of current flowing into said means for conducting second current is not greater than the predefined threshold, and

the amount of current flowing out of said means for conducting first current and said means for conducting second current is zero.

73. A method in accordance with claim 68, wherein said step of determining whether an electrical fault has occurred comprises:

determining the fault to be an amplifier open circuit fault if;

the amount of current flowing into said means for conducting first current is not greater than the predefined threshold, and

the amount of current flowing into said means for conducting second current is not greater than the predefined threshold, and

the amount of current flowing out of said means for conducting first current or said means for conducting second current is not zero, but not both.

74. A method in accordance with claim 68, wherein said step of determining whether an electrical fault has occurred comprises:

identifying a no fault condition if;

the amount of current flowing into said means for conducting a first current is not greater than the predefined threshold, and

the amount of current flowing into said means for conducting a second current is not greater than the predefined threshold, and

the amount of current flowing out of said means for conducting a first current and the amount of current flowing out of said means for conducting a second current are both not zero.

75. A method of isolating an electrical fault in a servo system comprising a servo motor and an amplifier, said method comprising the steps of:

(a) generating an activation signal for a pair of drive transistors which controls current flow in a first direction through a winding in the multi-phase motor, said pair of drive transistors comprising an upper drive transistor and a lower drive transistor;

(b) determining whether an amount of current flowing through the upper drive transistor is greater than a predefined threshold;

(c) determining whether an amount of current flowing through the lower drive transistor is zero;

(d) generating an activation signal for a second pair of drive transistors which controls current flow in a second direction through the winding in the multi-phase motor, said second pair of drive transistors comprising a second upper drive transistor and a second lower drive transistor;

(e) determining whether an amount of current flowing through the second upper drive transistor is greater than a predefined threshold;

(f) determining whether an amount of current flowing through the second lower drive transistor is zero; and

(h) determining the electrical fault condition as a function of the amount of current flowing through the upper drive transistor and lower drive transistor for each drive transistor pair.

76. A method of isolating an electrical fault in accordance with claim 75, wherein step (h) it is determined whether one of an amplifier short circuit, a motor winding short circuit, a motor winding-to-ground short circuit, an amplifier open circuit, or a motor winding open circuit exists.

77. A method of determining a fault to be an electrical fault in a servo system comprising a servo motor and a linear amplifier, said method comprising the steps of:

(a) determining an amount of source current applied to a first linear amplifier and a second linear amplifier, wherein said first and said second linear amplifiers are connected to opposing ends of a single motor winding;

(b) generating a first voltage command such that the first linear amplifier generates more voltage than the second linear amplifier;

(c) determining an amount of current flowing out of the second linear amplifier;

(d) generating a second voltage command such that the second linear amplifier generates more voltage than the first amplifier;

(e) determining an amount of current flowing out of the first linear amplifier; and

(f) isolating the electrical fault as a function of said amount of current flowing out of the first linear amplifier, the amount of current flowing out the second linear amplifier, and the amount of source current.

78. A method of isolating an electrical fault in accordance with claim 77, wherein step (f) it is determined whether one of a motor winding open circuit, a motor winding line-to-line short circuit, a motor winding line-to-ground short circuit, a linear amplifier transistor open circuit, a linear amplifier transistor short circuit, or a linear amplifier output bond wire open circuit exists.

79. A method of isolating an electrical fault in accordance with claim 77, wherein the step of isolating the electrical fault comprises the step of:

determining the fault to be a motor winding open circuit fault if;

the amount of current flowing out of the first linear amplifier is equal to a shunt current,

the amount of current flowing out of the second linear amplifier is equal to the shunt current, and

the amount of source current is equal to the shunt current.

80. A method of isolating a fault to be an electrical fault in accordance with claim 77, wherein the step of isolating the electrical fault comprises the step of:

determining the fault to be a motor winding line-to-line short circuit fault if;

the amount of current flowing out of the first linear amplifier is equal to an expected amount of current, and

the amount of current flowing out of the second linear amplifier is equal to the expected amount of current and there is erratic motion or no motion of the motor shaft.

81. A method of isolating an electrical fault in accordance with claim 77, wherein the step of isolating the electrical fault comprises the step of:

determining the fault to be a motor winding line-to-ground short circuit fault if;

the amount of current flowing out of the first linear amplifier is equal to zero, and

the amount of current flowing out of the second linear amplifier is equal to zero, and

the amount of source current is not equal to zero.

82. A method of isolating an electrical fault in accordance with claim 77, wherein the step of isolating the electrical fault comprises the step of:

determining the fault to be a linear amplifier transistor open circuit fault if;

the amount of current flowing out of the first linear amplifier equals an expected amount of current and the amount of current flowing out of the second linear amplifier equals zero, or

the amount of current flowing out of the first linear amplifier equals zero and the amount of current flowing out of the second linear amplifier equals the expected amount of current.

83. A method of isolating an electrical fault in accordance with claim 77, wherein the step of isolating the electrical fault comprises the step of:

determining the fault to be a linear amplifier short circuit fault if;

the amount of current flowing out of the first linear amplifier equals an expected amount of current and the amount of current flowing out of the second linear amplifier is greater than a maximum allowable amount of current, or

the amount of current flowing out of the first linear amplifier is greater than the maximum allowable amount of current and the amount of current flowing out of the second linear amplifier equals the expected amount of current.

84. A method of isolating an electrical fault in accordance with claim 77, wherein the step of isolating the electrical fault comprises the step of:

determining the fault to be an amplifier output bond wire open circuit fault if;

the amount of current flowing out of the first linear amplifier is equal to zero, and

the amount of current flowing out of the second linear amplifier is equal to zero, and

the amount of source current is equal to zero.

85. An apparatus for isolating an electrical fault in a servo system comprising a servo motor, said apparatus comprising:

first control means for generating a first current activation signal;

means for driving current in a first direction through a winding in the servo motor, responsive to said first current activation signal;

second control means for generating a second current activation signal;

means for driving current in a second direction through the winding in the servo motor, responsive to said means for generating a second current activation signal;

means for determining whether a fault exists as a function of an amount of current flowing into and out of said means for driving the first current and said means for driving the second current.

86. An apparatus in accordance with claim 85, wherein the servo motor is a dual-phase motor, and said means for driving the first current and said means for driving the second current are pulse-width modulated amplifiers.

87. An apparatus in accordance with claim 85, wherein the servo motor is a three-phase motor, and said means for driving the first current and said means for driving the second current are pulse-width modulated amplifiers.

88. An apparatus in accordance with claim 85, wherein the servo motor is a single-phase motor, and said means for driving the first current and said means for driving the second current are linear amplifiers.

89. An apparatus in accordance with claim 85, wherein said fault comprises a motor winding short circuit, a motor winding open circuit, an amplifier short circuit, or an amplifier open circuit.

90. An apparatus for isolating an electrical fault in a servo system comprising a servo motor and an amplifier, said apparatus comprising:

means for generating a first current command;

means for conducting current in a first direction through a motor winding, wherein said means for conducting a first current is responsive to the first current command;

means for determining whether an amount of current flowing into said means for conducting the first current is greater than a predefined threshold;

means for determining whether the amount of current flowing out of said means for conducting the first current is zero;

means for generating a second current command;

means for conducting current in a second direction through the motor winding, wherein said means for conducting the second current is responsive to the second current command;

means for determining whether an amount of current flowing into said means for conducting the second current is greater than the predefined threshold;

means for determining whether the amount of current flowing out of said means for conducting the second current is zero;

means for determining whether an electrical fault has occurred in the amplifier or whether an electrical fault has occurred in the motor winding as a function of the amount of current flowing into and out of said means for conducting the first current and said means for conducting the second current.

91. An apparatus for isolating an electrical fault in accordance with claim 90, wherein said means for determining whether an electrical fault has occurred comprises:

logic means for determining the fault to be a motor winding short circuit fault if;

the amount of current flowing into said means for conducting the first current is greater than the predefined threshold, and

the amount of current flowing into said means for conducting the second current is greater than the predefined threshold.

92. An apparatus for isolating an electrical fault in accordance with claim 90, wherein said means for determining whether an electrical fault has occurred comprises:

logic means for determining the fault to be an amplifier short circuit fault if;

the amount of current flowing into said means for conducting the first current is greater than the predefined threshold, or

the amount of current flowing into said means for conducting the second current is greater than the predefined threshold,

but not if both are greater than the predefined threshold.

93. An apparatus for isolating an electrical fault in accordance with claim 90, wherein said means for determining whether an electrical fault has occurred comprises:

logic means for determining the fault to be a motor winding open circuit fault if;

the amount of current flowing into said means for conducting the first current is not greater than the predefined threshold, and

the amount of current flowing into said means for conducting the second current is not greater than the predefined threshold, and

the amount of current flowing out of said means for conducting the first current and said means for conducting the second current is zero.

94. An apparatus for isolating an electrical fault in accordance with claim 90, wherein said means for determining whether an electrical fault has occurred comprises:

logic means for determining the fault to be an amplifier open circuit fault if;

the amount of current flowing into said means for conducting the first current is not greater than the predefined threshold, and

the amount of current flowing into said means for conducting the second current is not greater than the predefined threshold, and

the amount of current flowing out of said means for conducting the first current or said means for conducting the second current is not zero, but not both.

95. An apparatus for isolating an electrical fault in accordance with claim 90, wherein said means for determining whether an electrical fault has occurred comprises:

logic means for determining that a no fault condition exists if;

the amount of current flowing into said means for conducting the first current is not greater than the predefined threshold, and

the amount of current flowing into said means for conducting the second current is not greater than the predefined threshold, and

the amount of current flowing out of said means for conducting the first current and the amount of current flowing out of said means for conducting the second current are both not zero.

96. An apparatus for isolating an electrical fault in a servo system comprising a servo motor and an amplifier, said apparatus comprising:

control logic means for generating an activation signal for a pair of drive transistors which control current flow in a positive direction through a motor winding, said pair of drive transistors comprising an upper drive transistor and a lower drive transistor;

means for determining whether an amount of current flowing into the upper drive transistor is greater than a predefined threshold;

means for determining whether an amount of current flowing into the lower drive transistor is zero;

control logic means for generating an activation signal for a second pair of drive transistors which control current flow in a negative direction through the motor winding, said second pair of drive transistors comprising a second upper drive transistor and a second lower drive transistor;

means for determining whether an amount of current flowing into the second upper drive transistor is greater than a predefined threshold;

means for determining whether an amount of current flowing into the second lower drive transistor is zero; and

means for determining the electrical fault condition as a function of the amount of current flowing into the upper drive transistor and lower drive transistor for each drive transistor pair.

97. An apparatus for isolating an electrical fault in accordance with claim 96, wherein said electrical fault comprises an amplifier short circuit, a motor winding short circuit, a motor winding-to-ground short circuit, an amplifier open circuit, or a motor winding open circuit.

98. An apparatus for isolating an electrical fault in a servo system comprising a servo motor and a linear amplifier, said apparatus comprising:

supply current sensing means for determining an amount of supply current applied to a first linear amplifier and a second linear amplifier, wherein said first and said second linear amplifiers are connected to opposing ends of a motor winding;

control means for generating a first voltage command such that the first linear amplifier generates more voltage than the second linear amplifier;

current sensing means for determining an amount of current flowing out of the second linear amplifier;

control means for generating a second voltage command such that the second linear amplifier generates more voltage than the first amplifier;

current sensing means for determining an amount of current flowing out of the first linear amplifier; and

logic means for determining the electrical fault, without a test load and a test load relay, as a function of the amount of current flowing out of the first linear amplifier, the amount of current flowing out the second linear amplifier, and the amount of source current.

99. An apparatus for isolating an electrical fault in accordance with claim 98, wherein the electrical fault comprises a motor winding open circuit, a motor winding line-to-line short circuit, a motor winding line-to-ground short circuit, a linear amplifier transistor open circuit, a linear amplifier transistor short circuit, or a linear amplifier output bond wire open circuit.

100. An apparatus for isolating an electrical fault in accordance with claim 98, wherein said logic means for isolating the electrical fault comprises:

logic means for determining the fault to be a motor winding open circuit fault if;

the amount of current flowing out of the first linear amplifier is equal to a shunt current,

the amount of current flowing out of the second linear amplifier is equal to the shunt current, and

the amount of source current is equal to the shunt current.

101. An apparatus for isolating an electrical fault in accordance with claim 98, wherein said logic means for isolating the electrical fault comprises:

logic means for determining the fault to be a motor winding line-to-line short circuit fault if;

the amount of current flowing out of the first linear amplifier is equal to an expected amount of current, and

the amount of current flowing out of the second linear amplifier is equal to the expected amount of current and there is erratic motion or no motion of the motor shaft.

102. An apparatus for isolating an electrical fault in accordance with claim 98, wherein said logic means for isolating the electrical fault comprises:

logic means for determining the fault to be a motor winding line-to-ground short circuit fault if;

the amount of current flowing out of the first linear amplifier is equal to zero, and

the amount of current flowing out of the second linear amplifier is equal to zero, and

the amount of source current is not equal to zero.

103. An apparatus for isolating an electrical fault in accordance with claim 98, wherein said logic means for isolating the electrical fault comprises:

logic means for determining the fault to be a linear amplifier transistor open circuit fault if;

the amount of current flowing out of the first linear amplifier equals an expected amount of current and the amount of current flowing out of the second linear amplifier equals zero, or

the amount of current flowing out of the first linear amplifier equals zero and the amount of current flowing out of the second linear amplifier equals the expected amount of current.

104. An apparatus for isolating an electrical fault in accordance with claim 98, wherein said logic means for isolating the electrical fault comprises:

logic means for determining the fault to be a linear amplifier short circuit fault if;

the amount of current flowing out of the first linear amplifier equals an expected amount of current and the amount of current flowing out of the second linear amplifier is greater than a maximum allowable amount of current, or

the amount of current flowing out of the first linear amplifier is greater than the maximum allowable amount of current and the amount of current flowing out of the second linear amplifier equals the expected amount of current.

105. An apparatus for isolating an electrical fault in accordance with claim 98, wherein said logic means for isolating the electrical fault comprises:

logic means for determining the fault to be an amplifier output bond wire open circuit fault if;

the amount of current flowing out of the first linear amplifier is equal to zero, and

the amount of current flowing out of the second linear amplifier is equal to zero, and

the amount of source current is equal to zero.

106. A method comprising the steps of:

converting an array of analog image data values into a digital image comprising an array of pixel values,

sharpening the contrast of the digital image data with a two-dimensional (2D) sharpening filter.

107. A method in accordance with claim 106, wherein said step of sharpening the contrast of the digital image data comprises the steps of:

extracting a low frequency digital image from the digital image;

extracting a high frequency digital image from the digital image;

adjusting a low frequency digital image gain to high frequency digital image gain ratio; and

combining the low frequency digital image and the high frequency digital image.

108. A method in accordance with claim 107, wherein said step of sharpening the contrast of the digital image further comprises the step of:

measuring a contrast value for the digital image, wherein said low frequency digital image gain to high frequency digital image gain ratio is adjusted as a function of said contrast value.

109. A method in accordance with claim 108, wherein said step of measuring a contrast value comprises the steps of:

generating a difference value for adjacent pixel values; and

summing the difference values.

110. A method in accordance with claim 107, wherein said step of extracting a low frequency digital image comprises the step of:

averaging each pixel value in the digital image with each neighboring pixel value.

111. A method of sharpening the contrast of an input digital image comprising an array of pixel values, said method comprising the steps of:

extracting a low frequency digital image from the input digital image, said low frequency digital image comprising an array of pixel values;

extracting a high frequency digital image from the input digital image, said high frequency digital image comprising an array of pixel values;

determining a difference value between adjacent pixels along each row of the input digital image;

determining a contrast measure for the input digital image by summing the difference values;

adjusting a low frequency digital image gain to high frequency digital image gain ratio as a function of said contrast measure; and

combining each pixel value in the low frequency digital image with a corresponding pixel value in the high frequency digital image.

112. A method in accordance with claim 111, wherein said step of extracting a low frequency digital image comprises the step of:

replacing each pixel value in the input digital image with a low pass value based on each pixel value and a plurality of neighboring pixel value.

113. A method in accordance with claim 111, wherein said step of extracting a high frequency digital image comprises the step of:

generating a difference value between each pixel value in the input digital image and a corresponding pixel value in the low frequency digital image.

114. A method in accordance with claim 111, wherein said step of combining the low frequency digital image with the high frequency digital image comprises the step of:

summing each pixel value in the low frequency digital image with a corresponding pixel value in the high frequency digital image.

115. In an imaging system comprising a number “

n”

of analog-to-digital converters (ADCs), wherein each of the “

n”

ADCs converts every nth row or nth column of analog image data into digital image data, a method of removing ADC offset pattern differences from a digital image comprising the steps of;

generating “

n”

histograms, wherein each of the “

n”

histograms reflects a dynamic range of pixel values produced by a corresponding one of said “

n”

ADCs;

adjusting a pixel offset coefficient for each pixel associated with one of said “

n”

ADCs as a function of the dynamic range of the corresponding histogram; and

removing ADC offset pattern differences by adjusting each pixel value associated with said one of said “

n”

ADCs as a function of the corresponding, adjusted pixel offset coefficient.

116. A method in accordance with claim 115, wherein said step of adjusting a pixel offset coefficient comprises the steps of:

determining an average pixel value (H_n) for the corresponding histogram;

determining an average pixel value (H) based on the pixel values in each of the “

n”

number of histograms; and

adjusting a pixel offset coefficient as a function of the difference between the average pixel value (H_n) for the corresponding histogram and the average pixel value (H) based on the pixel values in each of the “

n”

histograms.

117. A method of enhancing a portion of a digital image comprising an array of pixel values, said method comprising the steps of:

extracting a desired portion of the digital image;

horizontally shifting the desired portion of the digital image by an amount equal to a fraction of a pixel width;

integrating the desired portion of the digital image with the horizontally shifted portion of the digital image to produce a first image field;

vertically shifting the desired portion of the digital image by a fraction of a pixel height,

horizontally shifting the vertically shifted portion of the digital image by the same fraction of a pixel width;

integrating the vertically shifted portion of the digital image with the vertically and horizontally shifted portion of the digital image to produce a second image field; and

interleaving the first image field and the second image field.

118. A method of focusing an image in an optical imaging system comprising a focus target, an optical focusing element and an array of detector elements, said method comprising the steps of:

adjusting the optical focusing element a plurality of times;

illuminating the array of detector elements with a high frequency test pattern after adjusting the optical focusing element, such that a random phase relationship exists between the test pattern and the array of detector elements;

converting the value associated with each detector element to a corresponding digital word;

generating a contrast measure after adjusting the optical focusing element based on the digital words; and

generating an optical focusing element control signal for controlling the adjustment of the optical focusing element as a function of a peak contrast measure.

119. A method in accordance with claim 118, wherein the high frequency test pattern is a checkerboard pattern comprising an array of alternatively light and dark squares.

120. A method in accordance with claim 118, wherein said step of generating a contrast measure comprises the steps of:

measuring a maximum intensity value from among the corresponding digital words;

measuring a minimum intensity value from among the corresponding digital words; and

determining the contrast measure as a function of the difference between said maximum intensity value and said minimum intensity value.

121. An apparatus for processing an image comprising:

analog-to-digital conversion means for converting an array of analog image data values into an array of digital image data; and

two-dimensional sharpen filter means for sharpening the contrast of the digital image data.

122. An apparatus in accordance with claim 121, wherein said 2D sharpen filter means comprises:

means for extracting a low frequency digital image from the digital image;

means for extracting a high frequency digital image from the digital image;

means for adjusting a low frequency image gain to high frequency image gain ratio; and

means for combining the low frequency digital image and the high frequency digital image.

123. An apparatus in accordance with claim 122, wherein said 2D sharpen filter means further comprises:

means for measuring a contrast value for the digital image, wherein said low frequency image gain to high frequency image gain ratio is adjusted as a function of said contrast value.

124. An apparatus method in accordance with claim 123, wherein said means for measuring a contrast value comprises:

means for summing pixel-to-pixel difference values.

125. An apparatus in accordance with claim 122, wherein said means for extracting a low frequency digital image comprises:

means for averaging each pixel value in the digital image with each neighboring pixel value.

126. An apparatus for sharpening the contrast of an input digital image comprising an array of pixel values, said apparatus comprising:

means for extracting a low frequency digital image from the input digital image;

means for extracting a high frequency digital image from the input digital image;

means for determining a difference value between adjacent pixels along each row of the input digital image;

means for determining a contrast measure for the input digital image by summing the difference values;

means for adjusting a low frequency digital image gain to high frequency digital image gain ratio as a function of said contrast measure; and

means for combining the low frequency digital image with the high frequency digital image.

127. An apparatus in accordance with claim 126, wherein said means for extracting a low frequency digital image comprising:

low pass filter convolution means for replacing each pixel value in the input digital image with a low pass pixel value, wherein each low pass pixel value is a function of each pixel value and a plurality of neighboring pixel values.

128. An apparatus in accordance with claim 126, wherein said means for extracting a high frequency digital image comprises:

means for removing the low frequency image from the input digital image.

129. An apparatus in accordance with claim 126, wherein said means for combining the low frequency digital image with the high frequency digital image comprises:

means for summing each pixel in the low frequency digital image with each pixel in the high frequency digital image.

130. In an imaging system comprising a number “

n”

of analog-to-digital converters (ADCs), wherein each of the “

n”

ADC converts every nth row or nth column of analog image data into digital image data, an apparatus for removing ADC offset pattern differences from a digital image comprising;

means for generating “

n”

histograms, wherein each of the “

n”

histograms reflects a dynamic range of pixel values produced by a corresponding one of said “

n”

ADCs;

means for adjusting a pixel offset coefficient for each pixel associated with one of said “

n”

ADCs as a function of the dynamic range of the corresponding histogram; and

means for removing ADC offset pattern differences by adjusting each pixel associated with said one of said “

n”

ADCs as a function of the corresponding adjusted pixel offset coefficient.

131. An apparatus in accordance with claim 130, wherein said means for adjusting the pixel offset coefficients comprises:

means for determining an average pixel value (H_n) for each of the “

n”

histograms;

means for determining an average pixel value (H) based on the pixel values in each of the “

n”

histograms; and

means for adjusting the pixel offset coefficients as a function of the difference between the average pixel value (H_n) for the corresponding histogram and the average pixel value (H) based on the pixel values in each of the n histograms.

132. An apparatus for enhancing a portion of a digital image comprising:

windowing means for extracting a desired portion of an input digital image;

means for horizontally shifting the desired portion of the input image by an amount equal to a fraction of a pixel width, and

means for generating a first image field by integrating the desired portion of the input image with the horizontally shifted portion of the input image;

means for vertically shifting the desired portion of the input image by the same fraction of a pixel height,

means for horizontally shifting the vertically shifted portion of the input image by the same fraction of a pixel height, and

means for generating a second image field by integrating the vertically shifted portion of the input image with the vertically and horizontally shifted portion of the input image; and

means for interleaving the first image field and the second image field.

133. An apparatus in accordance with claim 132, wherein said means for horizontally and vertically shifting the desired portion of the input image includes a fast steering mirror.

134. An apparatus for focusing an image in an optical imaging system comprising an optical focusing element and an array of detector elements, said apparatus comprising:

means for adjusting the optical focusing element a plurality of times;

means for illuminating the array of detector elements with a high frequency test pattern after adjusting the optical focusing element, wherein a random phase relationship exists between the test pattern and the array of detector elements;

analog-to-digital conversion means for converting the value associated with each detector element to a corresponding digital word;

means for generating a peak contrast measure after adjusting the optical focusing element based on the digital words; and

means for generating an optical focusing element control signal which controls said means for adjusting the optical focusing element as a function of a peak contrast measure.

135. An apparatus in accordance with claim 134, wherein the high frequency test pattern is a checkerboard pattern comprising an array of alternatively dark and light squares.

136. An apparatus in accordance with claim 134, wherein said means for generating a contrast measure comprising:

means for measuring a maximum intensity value from among the corresponding digital words;

means for measuring a minimum intensity value from among the corresponding digital words; and

means for determining the contrast measure as a function of the difference between said maximum intensity value and said minimum intensity value.

137. An optical image system comprising:

a housing assembly;

a window associated with said housing assembly, through which optical energy passes; and

an electromagnetic interference grid for transmitting on-axis optical energy through the window and for radially diffracting off-axis electromagnetic interference, wherein said electromagnetic interference grid is integrated into said window, and wherein said electromagnetic interference grid comprises an array of circular grid elements aligned in rows and columns.

138. A method of aligning first radiation from a first source with second radiation from a second source, said method comprising the steps of:

aligning the first radiation with a plurality of openings in a reticle pattern, said plurality of openings being spaced away from a centrally located opening;

projecting said second radiation through an opening in the reticle pattern, wherein the opening has lateral edges that project radially inward toward the centrally located opening;

translating a path of said second radiation until it is coincident with a lateral edge; and

translating said path toward the centrally located opening along the lateral edge toward the centrally located opening.

139. A method in accordance with claim 138, further comprising the step of:

translating a path of said second radiation along the lateral edge of the opening until the energy is coincident with an inner edge of the opening;

translating said path in accordance with a number of grid positions; and

aligning the path in accordance with the grid position that results in a peak energy detection through the centrally located opening.

140. A method in accordance with claim 138, wherein the first radiation is infrared radiation.

141. A method in accordance with claim 138, wherein the second radiation is laser radiation.

142. A method in accordance with claim 138, wherein said plurality of openings, through which said first radiation passes, are of equal distance from the centrally located opening.

143. In a forward-looking infrared (FLIR)/laser based optical imaging system, a method of aligning IR line-of-sight (LOS) and laser LOS comprising the steps of:

projecting infrared (IR) energy from an IR energy source through a reticle pattern onto a focal plane array;

aligning the IR LOS such that a maximum amount of IR energy passes through a plurality of peripheral openings in the reticle pattern, wherein the peripheral openings are of equal distance from a centrally located opening;

projecting laser energy from a laser transmitter through one of a plurality of wedge-shaped openings in the reticle pattern, wherein each of the wedge-shaped openings has lateral edges that project radially inward toward the centrally located opening;

translating the laser LOS until it is coincident with a lateral edge; and

translating the laser LOS toward the centrally located opening along the lateral edge.

144. A method in accordance with claim 143, further comprising the steps of:

translating the laser LOS along the lateral edge until the laser LOS is coincident with an inner edge of the one wedge-shaped opening;

translating the laser LOS in accordance with a number of grid positions; and

aligning the laser LOS in accordance with the grid position that results in a peak laser energy detection through the centrally located opening.

145. A method in accordance with claim 143, further comprising the step of:

focusing the IR energy.

146. A method in accordance with claim 145, wherein said step of focusing the IR energy comprises the steps of:

projecting IR energy through an array of square openings in the reticle pattern, such that a high frequency test pattern appears on the focal plane array;

adjusting an IR energy optical focusing element a plurality of times;

generating a contrast measure for the high frequency test pattern after each adjustment of the optical focusing element; and

focusing the IR energy as a function of a peak contrast measure.

147. A method in accordance with claim 146, wherein the high frequency test pattern is a checkerboard pattern comprising an array of alternatively dark and light squares.

148. In an optical system that employs at least two energy sources, an apparatus for aligning a first energy source with a second energy source, said apparatus comprising:

means for aligning the first energy source with a plurality of openings in a reticle pattern such that said plurality of openings in the reticle pattern are of equal distance from a centrally located opening;

means for projecting energy from the second energy source through an opening in the reticle pattern, wherein the opening has lateral edges that project radially inward toward the centrally located opening;

means for translating the energy from the second energy source until it is coincident with a lateral edge; and

means for translating said energy toward the centrally located opening along the lateral edge.

149. An apparatus in accordance with claim 148, further comprising:

means for translating a path of said second radiation along the lateral edge of the opening until the energy is coincident with an inner edge of the opening;

means for translating said path in accordance with a number of grid positions; and

means for aligning said path in accordance with the grid position that results in a peak energy detection through the centrally located opening.

150. An apparatus in accordance with claim 148, wherein the first energy source is an infrared energy source.

151. An apparatus in accordance with claim 148, wherein the second energy source is a laser transmitter.

152. In a forward-looking infrared (FLIR)/laser based optical imaging system, an apparatus for boresighting IR line-of-sight (LOS) and laser LOS comprises:

IR energy source means for projecting infrared (IR) energy through a reticle pattern onto a focal plane array;

IR optics means for aligning the IR LOS such that a maximum amount of IR energy passes through a plurality of peripheral openings in the reticle pattern, wherein the peripheral openings are of equal distance from a centrally located opening;

laser transmitter means for projecting laser energy through one of a plurality of wedge-shaped openings in the reticle pattern, wherein each of the wedge-shaped openings has lateral edges that project radially inward toward the centrally located opening;

laser optics means for translating the laser LOS until it is coincident with a lateral edge; and

laser optics means for translating the laser LOS toward the centrally located opening along the lateral edge.

153. An apparatus in accordance with claim 152, further comprises:

first laser optics for translating the laser LOS along the lateral edge until the laser LOS is coincident with an inner edge of the one wedge-shaped opening;

second laser optics for translating the laser LOS in accordance with a number of grid positions; and

means for aligning the laser LOS in accordance with the grid position that results in a peak laser energy detection through the centrally located opening.

154. An apparatus in accordance with claim 153, wherein the laser optics means for translating the laser LOS comprises a pair of Risley prisms.

155. An apparatus in accordance with claim 152, further comprises:

means for focusing the IR energy.

156. An apparatus in accordance with claim 154, wherein said means for focusing the IR energy comprises:

IR energy source means for projecting IR energy through an array of square openings in the reticle pattern, such that a high frequency test pattern appears on the focal plane array;

means for adjusting an IR energy optical focusing element a plurality of times;

means for generating a contrast measure for the high frequency test pattern after each adjustment of the optical focusing element; and

means for focusing the IR energy as a function of a peak contrast measure.

157. An apparatus in accordance with claim 156, wherein the high frequency test pattern is a checkerboard pattern comprising an array of alternatively dark and light squares.