System, method, and apparatus for passive, multi-spectral, optical identification of remote objects

• US 7,290,710 B2
• Filed: 08/21/2003
• Issued: 11/06/2007
• Est. Priority Date: 08/21/2003
• Status: Active Grant

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Torti, Russell G., Betush, William J., Reed, James R.
• Primary Examiner(s): Stcyr; Daniel
• Assistant Examiner(s): TAYLOR, APRIL ALICIA
• Application Number:
  US10/645,029
• Publication Number:
  US 20050040245A1
• Time in Patent Office: 1,538 Days
• Field of Search: 235/384, 235/468, 235/454, 235400-411, 340/522, 367/128
• US Class Current: 235/454
• CPC Class Codes: G06K 19/06009 with optically detectable marking G06K19/063, G06K19/08 take precedence

Abstract

A system passively identifies objects at large distances with an integrated two-dimensional pattern, spectral tailoring, and an imaging system. Encoded information allows objects of various origin and configuration to be easily and rapidly identified by optical means, but is invisible to the naked eye. The devices used for detecting the objects may be ground-based, airborne, or even satellite-based, and can track engagements of such marked objects in real-time. A tailored reflective surface at a specific wavelength band is applied to the exteriors of the objects to form a unique signature. A scanning system passively records the light emanating from the signature in the specific band, and recognizes the signature to discern what the object is based on a database of information.

Claims

1. A system for passively and remotely identifying objects, comprising:

a series of signatures positioned on exterior surfaces of a plurality of objects, each of the signatures having an encoded, two-dimensional, reflective configuration that is spectrally tailored to define a unique signature for each of the objects; and

an optical imaging system for remotely and passively detecting and decoding the signatures and thereby identifying the objects based on the signatures, the optical imaging system having a scanning system that passively detects light emanating from the signatures in respective, specific wavelength bands, and recognizes the signatures to discern what the objects are based on a database of information.

2. The system of claim 1, wherein a remote position of the scanning system is selected from the group consisting of airborne and satellite-based.

3. The system of claim 1, wherein a material used to form reflective surfaces of the signatures only reflects energy in wavelength band widths of approximately one-half wavelength.

4. The system of claim 1, wherein the signatures utilize patterns and symbols to further distinguish between the objects, and the wavelength bands are encoded to lie outside of threat bands of hostile detectors and hostile guided weapons.

5. The system of claim 1, wherein the signatures are painted on the objects.

6. The system of claim 1, wherein the signatures are invisible to the naked human eye such that no intuitive knowledge can be gained by human observation of the signatures, and the objects comprise airborne aircraft, grounded aircraft, and tanks.

7. The system of claim 1, wherein the system tracks engagements of the objects and movement of supplies to and from the objects in real-time.

8. The system of claim 1, wherein

each of the signatures includes a substrate and a thin film mounted on a surface of the substrate, the thin film comprising a laminate including a plurality of layers having a high index of refraction that are interleaved with a plurality of layers having a low index of refraction, each of the layers having a thickness of approximately a fraction of a wavelength of the light to define the wavelength band for the unique signature;

and

a value of a reflectance of the wavelength band is dependent upon the number of layers in the signature.

9. The system of claim 8, wherein the wavelength band has multiple absorption lines having a very narrow, approximately half-wave bandwidth that is undetectable by sensors that utilize band averaging techniques.

10. The system of claim 8, wherein:

the signature utilizes a bar code configuration that is invisible to the naked human eye and can be detected and identified remotely when applied to an exterior surface of an object;

the light reflected by the signature is infrared light; and

the thin film is a dielectric and vapor-deposited on the substrate.

11. The system of claim 8, further comprising a center layer having a high index of refraction and located between the layers, the center layer also having a thickness that is greater than the thickness of the layers;

and

the thickness of each of the layers is approximately one-quarter wavelength, and the thickness of the center layer is approximately one-half wavelength.

12. The system of claim 8, wherein a peak reflectance of the signature is in a range from 50 to 100% reflectance, which is higher than a reflectance of a structure on which the signature is located, and a minimum reflectance of the signature is approximately one-half percent reflectance, which is lower than the reflectance of the structure on which the signature is located.

13. A system for passively and remotely identifying an object, comprising:

a signature positioned on an exterior surface of an object, the signature comprising a substrate and a thin film mounted on a surface of the substrate, the thin film including a laminate including a plurality of layers having a high index of refraction that are interleaved with a plurality of layers having a low index of refraction; and

an optical imaging system for remotely and passively detecting and decoding the signature and thereby identifying the object based on the signature, the optical imaging system having a scanning system that passively detects light emanating from the signature in a wavelength band, and recognizes the signature to discern what the object is based on a database of information.

14. The system of claim 13, wherein each of the layers has a thickness of approximately a fraction of a wavelength of the light to define the wavelength band, and the thin film is a dielectric and vapor-deposited on the substrate.

15. The system of claim 13, wherein:

the signature utilize patterns and symbols to further distinguish between the objects, and the signature is adhered to the objects as appliqué

; and

a peak reflectance of the signature is in a range from 50 to 100% reflectance, which is higher than a reflectance of a structure on which the signature is located, and a minimum reflectance of the signature is approximately one-half percent reflectance, which is lower than the reflectance of the structure on which the signature is located.

16. The system of claim 13, wherein the signature is painted on the objects and the signature is invisible to the naked human eye such that no intuitive knowledge can be gained by human observation of the signature.

17. The system of claim 13, wherein the objects comprise equipment, airborne aircraft, grounded aircraft, and tanks, and the system tracks engagements of the objects and movement of supplies to and from the objects in real-time.

18. The system of claim 13, wherein the wavelength band has multiple absorption lines having a very narrow, approximately half-wavelength bandwidth that is undetectable by sensors that utilize band averaging techniques.

19. The system of claim 13, further comprising a center layer having a high index of refraction and located between the layers, the center layer also having a thickness that is greater than the thickness of the layers.

20. The system of claim 19, wherein the thickness of each of the layers is approximately one-quarter wavelength, and the thickness of the center layer is approximately one-half wavelength.