Optical detection system

Abstract

The present invention pertains to radiant energy systems and more particularly to systems exhibiting the retroreflection principle wherein the system comprises a focusing means and a surface exhibiting some degree of reflectivity positioned near the focal plane of the device, and wherein incident radiation falling within the field-of-view of said system is reflected back in a direction which is parallel to the incident radiation. The present invention has great applicability in military optical system applications for detecting the presence of an enemy employing surveillance equipment and for neutralizing this surveillance capability.

1. The method of detecting an uncooperative optical system including a focusing means and a surface exhibiting some degree of reflectivity disposed substantially in the focal plane of said focusing means, said method comprising
 the step of directing optical energy at said optical system whereby that portion of said energy incident upon said optical system is retroreflected with an optical gain to thereby form a beam of retroreflected optical energy, and  
 the step of detecting said retroreflected optical energy having a radiant flux density in excess of a preselected value to thereby indicate the presence of said optical system.  
 
     
     
       2. The method of  claim 1 , including
 the step of scanning a predetermined geographical area to detect the presence of an optical system therein.  
 
     
     
       3. The method of  claim 2 , including
 the step of tracking said optical system after the presence thereof has been detected.  
 
     
     
       4. The method of  claim 3 , including the step of directing a weapon at the position of said optical system after the detection thereof. 
     
     
       5. The method of  claim 1 , wherein
 the radiant energy directed at said optical system is in the nonvisible region.  
 
     
     
       6. The method of  claim 1 , wherein
 the radiant energy directed at said optical system is light energy in the nonvisible region.  
 
     
     
       7. The method of  claim 6 , wherein
 the light energy in the nonvisible region is infrared.  
 
     
     
       8. The method of  claim 4 , wherein
 said weapon is a laser.  
 
     
     
       9. The method of  claim 1 , wherein
 the radiant energy is in the ultraviolet portion of the electromagnetic spectrum.  
 
     
     
       10. The method of  claim 1 , wherein
 the radiant energy is X-ray energy.  
 
     
     
       11. The method of  claim 1 , wherein
 the radiant energy comprises high energy particles related to quantum mechanics.  
 
     
     
       12. The method of  claim 1 , wherein
 the radiant energy is acoustical energy.    
     
     
       13. The method recited in  claim 1  wherein
 said optical system is a telescope.  
 
     
     
       14. The method recited in  claim 1  wherein
 said optical system is a binocular.  
 
     
     
       15. The method recited in  claim 1  wherein
 said optical system is a periscope.  
 
     
     
       16. The method recited in  claim 1  wherein
 said optical system is a human eye.  
 
     
     
       17. Apparatus for detecting the presence of an uncooperative optical system including a focusing means and a surface exhibiting some degree of reflectivity disposed substantially in the focal plane of said focusing means, said apparatus comprising
 means for producing radiant energy,  
 means for directing said energy toward said optical system whereby said energy is retroreflected with an optical gain by said optical system, and  
 means for detecting said retroreflected energy having a radiant flux density in excess of a preselected value to thereby indicate the presence of said optical system.  
 
     
     
       18. Apparatus in accordance with  claim 17  wherein said means for producing radiant energy is a radiant energy source operative in the nonvisible region. 
     
     
       19. Apparatus in accordance with  claim 17 , wherein said means for producing radiant energy is a radiant energy light source. 
     
     
       20. Apparatus in accordance with  claim 19 , wherein said radiant energy light source is an infrared source. 
     
     
       21. Apparatus in accordance with  claim 17 , wherein said means for producing radiant energy, said means for directing said energy toward said optical system, and said means for detecting the energy retroreflected by said optical system, form an optical transceiver. 
     
     
       22. Apparatus in accordance with  claim 21 , wherein said means for producing rays of  radiant energy,
 said means for directing said rays  energy toward said optical instrument  system, and  
 said means for detecting the rays  energy retroreflected by said optical instrument  system are concentrically disposed with respect to one another.  
 
     
     
       23. Apparatus in accordance with  claim 22 , wherein said means for producing radiant energy, said means for directing said energy toward said optical system, and said means for detecting said energy retroreflected by said optical system are concentrically disposed with respect to one another. 
     
     
       24. Apparatus in accordance with  claim 22 , wherein
 said means for producing radiant energy comprises a radiant energy source  
 said means for directing said energy toward said optical system comprises a primary mirror having a substantially parabolic configuration, and  
 said means for detecting said retroreflected energy comprising 
 a detector  
 said primary mirror, and  
 a secondary mirror having a substantially planar configuration  
 
 said primary mirror having an aperture concentric with the principal axis thereof,  
 said radiant energy source being positioned 
 adjacent the non-reflecting surface of said secondary mirror,  
 in the focal plane of said primary mirror,  
 
 said secondary mirror being positioned 
 adjacent said primary mirror, and  
 having the reflecting surface of said secondary mirror facing the reflecting surface of said primary mirror, and  
 
 said detector 
 being positioned adjacent the non-reflecting surface of said primary mirror,  
 being in axial alignment with the aperture thereof,  
 being positioned in the focal plane of said detection means.  
 
 
     
     
       25. Apparatus in accordance with  claim 22 , wherein
 said means for producing radiant energy comprises a radiant energy source,  
 said means for directing said energy toward said optical system comprises 
 a collecting mirror having a substantially elliptical configuration  
 a primary mirror having a substantially parabolic configuration, and  
 a secondary mirror having a substantially planar configuration,  
 
 said means for detecting said retorreflected energy comprising 
 a detector, and  
 said primary mirror,  
 
 said primary mirror having an aperture concentric with the principal axis thereof,  
 said secondary mirror being positioned with the reflecting surface thereof facing the reflecting surface of said primary mirror,  
 said radiant energy source 
 being positioned between the reflecting surfaces of said primary and secondary mirrors, and  
 in axial alignment with said mirrors,  
 
 said collecting mirror being positioned adjacent the non-reflecting surface of said primary mirror, 
 in axial alignment with the aperture thereof, and said detector being positioned in the focal plane of said direction means adjacent the non-reflecting surface of said secondary mirror in the focal plane of said primary mirror.  
 
 
     
     
       26. Apparatus in accordance with  claim 21 , wherein
 said means for producing incident radiant energy is a radiant energy light source operative in the nonvisible region.  
 
     
     
       27. Apparatus in accordance with  claim 23 , wherein
 said radiant energy light source is an infrared source.  
 
     
     
       28. Apparatus in accordance with  claim 17 , wherein
 said means for directing said incident energy towards said optical system having scanning means operatively associated therewith to cause said rays  energy to scan a predetermined geographical area to detect and locate said optical system.  
 
     
     
       29. Apparatus in accordance with  claim 28 , including
 tracking means operatively associated with said scanning means to thereby track the movement of said optical system after detection thereof.  
 
     
     
       30. Apparatus in accordance with  claim 28 , including
 weapon means operatively associated with said tracking means for use against said optical system after detection thereof.  
 
     
     
       31. Apparatus in accordance with  claim 30 , wherein
 said weapon means is high energy source.  
 
     
     
       32. Apparatus in accordance with  claim 31 , wherein
 said high energy source is a laser.  
 
     
     
       33. The apparatus recited in  claim 17  wherein said optical system is a telescope. 
     
     
       34. The apparatus recited in  claim 17  wherein
 said optical system is a binocular.  
 
     
     
       35. The apparatus recited in  claim 17  wherein
 said optical system is a periscope.  
 
     
     
       36. The apparatus recited in  claim 17  wherein
 said optical system is a human eye.  
 
     
     
       37. Apparatus for measuring the retroreflective characteristics of an optical system consisting of at least a focusing means and a surface exhibiting some degree of reflectivity disposed substantially in the focal plane of said focusing means, said apparatus comprising
 a radiant energy source,  
 detection means,  
 measuring means connected to said detection means, and  
 means for directing said radiant energy produced by said source at said optical system,  
 whereby said radiant energy is retroreflected with an optical gain by said optical system and detected by said detecting means and the output thereof is coupled to said measuring means.  
 
     
     
       38. An optical system accordance with  claim 37 , including means disposed between said radiant energy source and said optical system
 for transmitting a portion of the radiant energy produced by said radiant energy source toward said optical system, and  
 for transmitting a portion of said energy retroreflected by said optical system toward said detecting means.  
 
     
     
       39. An optical system in accordance with  claim 38 , wherein said directing means and said detecting means are substantially concentric. 
     
     
       40. The method of detecting the presence of devices which exhibit the phenomenon of retroreflection, said method comprising
 the step of directing radiant energy at said devices whereby said radiant energy is retroreflected with an optical gain by said devices, and  
 the step of detecting said retroreflected radiant energy which is in excess of a preselected radiant flux density level to thereby indicate the presence of said devices.  
 
     
     
       41. The method of  claim 40 , including the step of analyzing said retroreflected radiant energy to thereby determine the spatial and temporal characteristics of said devices. 
     
     
       42. Apparatus for detecting the presence of devices which exhibit the phenomenon of retroreflection, said apparatus comprising
 means for producing radiant energy,  
 means for directing said energy toward said devices whereby said energy is retroreflected with an optical gain by said devices, and  
 means for detecting said retroreflected energy which is in excess of a preselected radiant flux density level to thereby indicate the presence of said devices.  
 
     
     
       43. apparatus for measuring the retroreflective characteristics of devices which exhibit the phenomenon of retroreflection, said apparatus comprising
 means for producing radiant energy,  
 means for directing said energy toward said devices whereby said energy is retroreflected with an optical gain by said devices,  
 means for detecting said retroreflected energy which is in excess of a preselected radiant flux density level to thereby indicate the presence of said devices, and  
 means for analyzing said detected energy to thereby determine the characteristics of said devices.  
 
     
     
       44. The method of detecting an uncooperative and non-radiating microwave antenna system consisting of at least a microwave focusing means and a microwave feed horn disposed substantially at the focal point of said focusing means, said method comprising
 the step of directing swept frequency microwave energy at said antenna system whereby substantially all energy at the operating frequency of said antenna system which is impingent thereon is focused by said focusing means and absorbed by said feed horn and energy of any other frequency is retroreflected by said antenna system with an energy density gain to thereby form a beam of retroreflected microwave energy, and  
 the step of detecting said retroreflected energy having an energy density in excess of a preselected value to thereby indicate the presence of said antenna system.  
 
     
     
       45. The method recited in  claim 44  further including
 the step of determining the frequency at which the energy density of said retroreflected energy is of a minimum level to thereby determine the operating frequency of said antenna system.  
 
     
     
       46. The method recited in  claim 44  further including
 the step of analyzing any temporal characteristics of said energy retroreflected by said antenna system.  
 
     
     
       47. The method recited in  claim 44  further including
 the step of analyzing any spatial characteristics of said beam of energy retroreflected by said antenna system.  
 
     
     
       48. A method of detecting characteristics or properties of an optical system based on a retroreflected beam, comprising:
 transmitting radiant energy at an optical system having retroreflective characteristics;    receiving reflected radiant energy after retroreflection of the radiant energy;    detecting the reflected radiant energy after retroreflection to determine at least one characteristic or property of the optical system.   
     
     
       49. The method of  claim 48 , wherein the at least one characteristic or property is determined based on temporal properties of the reflected radiant energy. 
     
     
       50. The method of  claim 48 , wherein the at least one characteristic or property is determined based on spectral properties of the reflected radiant energy. 
     
     
       51. The method of  claim 48 , wherein one of the at least one property or characteristic is a relative position of the retroreflective portion of the optical system. 
     
     
       52. The method of  claim 48 , further comprising redirecting the reflected radiant energy using a beam splitter. 
     
     
       53. The method of  claim 52 , wherein the beam splitter passes the radiant energy toward the retroreflective portion of the optical system. 
     
     
       54. The method of  claim 48 , further comprising:
 comparing the reflected radiant energy with the transmitted radiant energy as part of the detecting.   
     
     
       55. The method of  claim 48 , wherein the transmitting includes directing the radiant energy to scan a preselected area. 
     
     
       56. The method of  claim 48 , wherein the transmitting and receiving are performed by portions of a concentric optical system. 
     
     
       57. The method of  claim 48 , wherein the radiant energy is generated by a laser. 
     
     
       58. The method of  claim 48 , wherein the reflected radiant energy has an optical gain. 
     
     
       59. The method of  claim 48 , wherein the at least one property or characteristic includes at least one property or characteristic of a reticle within the optical system. 
     
     
       60. The method of  claim 48 , wherein the optical system includes a retroreflector having a lens positioned in front of a surface having at least some reflectivity. 
     
     
       61. An apparatus for detecting characteristics or properties of an optical system based on a retroreflected beam, comprising:
 a source of radiant energy;    a detector; and    an optical system that directs radiant energy from the source toward a retroreflective surface and returns reflected radiant energy to the detector;    wherein the detector determines at least one characteristic or property of the optical system.   
     
     
       62. The apparatus of  claim 61 , wherein the optical system further comprises a beam splitter that directs the radiant energy to the detector and redirects the reflected radiant energy to the detector. 
     
     
       63. The apparatus of  claim 61 , further comprising a collimator that collimates the radiant energy from the source. 
     
     
       64. The apparatus of  claim 61 , wherein the at least one characteristic or property is determined based on at least one temporal property of the reflected radiant energy. 
     
     
       65. The apparatus of  claim 61 , wherein the at least one characteristic or property is determined based on at least one spectral characteristic of the optical system. 
     
     
       66. The apparatus of  claim 61 , wherein the detector compares the reflected radiant energy with the transmitted radiant energy as part of the detecting. 
     
     
       67. The apparatus of  claim 61 , wherein the at least one characteristic or property includes a relative position of the retroreflective portion of the optical system. 
     
     
       68. The apparatus of  claim 61 , wherein the source of radiant energy is a laser. 
     
     
       69. The apparatus of  claim 61 , wherein the reflected radiant energy has an optical gain. 
     
     
       70. The apparatus of  claim 61 , wherein the at least one characteristic or property includes at least one characteristic or property associated with a reticle within the optical system. 
     
     
       71. The apparatus of  claim 61 , wherein the optical system includes a retroreflector having a lens positioned in front of a surface having at least some reflectivity.