Enhanced vision system sensitive to infrared radiation

• US 6,373,055 B1
• Filed: 05/14/2001
• Issued: 04/16/2002
• Est. Priority Date: 03/05/1999
• Status: Expired due to Term

• Current Assignee: Teledyne FLIR LLC (Teledyne Technologies Incorporated)
• Original Assignee: FLIR Systems, Inc. (Teledyne Technologies Incorporated)
• Inventors: Kerr, Jones Richard
• Primary Examiner(s): Evans, F. L
• Application Number:
  US09/855,398
• Time in Patent Office: 337 Days
• Field of Search: 250/330, 348/33, 348/113, 348/115, 348/116, 348/164
• US Class Current: 250/330
• CPC Class Codes: B64D 2045/0075 Adaptations for use of electronic flight bags in aircraft; Supports therefor in the cockpit
• CPC Class Codes: B64D 43/00 Arrangements or adaptations of instruments arrangements of cameras B64D47/08; aeronautical measuring instruments per se G01C
• CPC Class Codes: B64D 45/08 optical
• CPC Class Codes: G01C 21/20 Instruments for performing navigational calculations G01C21/24, G01C21/26 take precedence
• CPC Class Codes: G06T 1/20 Processor architectures; Processor configuration, e.g. pipelining
• CPC Class Codes: G08G 5/0021 located in the aircraft
• CPC Class Codes: G08G 5/025 Navigation or guidance aids radar or analogous systems specially adapted for landing purposes G01S13/913
• CPC Class Codes: H01L 27/14649 Infrared imagers
• CPC Class Codes: H04N 5/33 Transforming infrared radiation cameras or camera modules for generating image signals from infrared radiation H04N23/20; circuitry of SSIS for transforming infrared radiation into image signals H04N25/20

Abstract

An enhanced vision system and method for use with vision systems with an imager sensitive to infrared radiation of less than 2-microns in wavelength, to produce a first image signal. Another imager sensitive to infrared radiation at least 3-microns in wavelength may be used to produce a second image signal. Preferably, the first image signal represents sensed electric light sources, and the second image signal represents sensed background such as terrain, runways, structures, and obstacles. A signal processor combines an image signal representing locally maximum values of the first image signal with the second image signal to create a displayed image.

Claims

1. An enhanced vision system, comprising:

a detection system configured to detect electromagnetic radiation, the detection system being adapted to produce a first image signal corresponding to radiation detected over a first range of wavelengths and a second image signal corresponding to radiation detected over a second range of wavelengths, where the first and second ranges are at least partially nonoverlapping; and

a signal processor operatively associated with the detection system that combines an image signal representing locally maximum values of the first image signal with the second image signal to create a displayed image.

2. The enhanced vision system of claim 1, where the detection system includes a first detector adapted to produce the first image and a second detector adapted to produce the second image.

3. The enhanced vision system of claim 1, where the detection system includes an integrated detector sensitive to both the first and second ranges of wavelengths adapted to produce both the first and second images.

4. The enhanced vision system of claim 1, where the first range of wavelengths lies below about 2.4 microns.

5. The enhanced vision system of claim 4, where the first range of wavelengths lies above about 0.4 microns.

6. The enhanced vision system of claim 5, where the first range of wavelengths lies above about 1.5 microns.

7. The enhanced vision system of claim 1, where the second range of wavelengths lies above about 0.4 microns.

8. The enhanced vision system of claim 7, where the second range of wavelengths lies above about 3 microns.

9. The enhanced vision system of claim 8, where the second range of wavelengths lies above about 8 microns.

10. The enhanced vision system of claim 7, where the second range of wavelengths lies below about 14 microns.

11. The enhanced vision system of claim 1, where the first and second ranges of wavelengths are nonoverlapping.

12. The enhanced vision system of claim 1, further comprising a spectral filter assembly configured to limit the passage to the detection system of radiation having wavelengths outside at least one of the first and second ranges of wavelengths.

13. The enhanced vision system of claim 12, where the spectral filter assembly includes a daylight filter configured to limit passage to the detection system of visible light during daylight operation.

14. The enhanced vision system of claim 1, where the locally maximum values are represented graphically as predefined dots.

15. The enhanced vision system of claim 1, further comprising a display operatively associated with the signal processor and configured to present the displayed image.

16. The enhanced vision system of claim 1, where the signal processor automatically combines the image signal representing locally maximum values of the first image signal with the second image signal to create the displayed image.

17. The enhanced vision system of claim 1, further comprising:

a visible light sensor; and

a processor that determines when adequate visibility is available of a desired object, and that deactivates at least a portion of the displayed image when adequate visibility is available.

18. The enhanced vision system of claim 1, where the detection system further is adapted to produce a third image signal corresponding to radiation detected over a third range of wavelengths, and where the signal processor further combines the image signal representing locally maximum values of the first image signal with the second image signal and the third image signal to create the displayed image.

19. The enhanced vision system of claim 1, where the second image is processed to reduce noise and/or enhance contrast.

20. The enhanced vision system of claim 1, further comprising an object identifier that compares at least one of the image signals to predefined data representative of expected sensed objects, and that modifies the at least one of the image signals to match the predefined data when sufficient similarity is found between the at least one of the image signals and the predefined data.

21. The enhanced vision system of claim 1, further comprising a location calculator that determines the difference between the relative location of an identified object within at least one of the image signals and a calculated location for the identified object based on predefined data, and that calculates a geographical position of the detector based on the determined difference.

22. An enhanced vision system, comprising:

means for detecting electromagnetic radiation adapted to produce a first image signal corresponding to radiation detected over a first range of wavelengths and a second image signal corresponding to radiation detected over a second range of wavelengths, where the first and second ranges are at least partially nonoverlapping;

means for processing the first image signal to produce a modified first image signal representing locally maximum values of the first image signal; and

means for combining the modified first image signal with the second image signal to create a displayed image;

where the means for detecting, processing, and combining are operatively associated.

23. The enhanced vision system of claim 22, further comprising means for presenting the displayed image.

24. The enhanced vision system of claim 22, further comprising means for identifying objects in at least one of the image signals by comparing the at least one of the image signals to predefined data representative of expected sensed objects.

25. The enhanced vision system of claim 22, further comprising means for calculating locations by determining the difference between the relative location of an identified object within at least one of the image signals and a calculated location for the identified object based on predefined data and calculating a geographical position of the detector based on the determined difference.

26. An enhanced vision system, comprising:

a detection system configured to detect electromagnetic radiation, the detection system being adapted to produce a first image signal corresponding to radiation detected over a first range of wavelengths, a second image signal corresponding to radiation detected over a second range of wavelengths, and a third image signal corresponding to radiation detected over a third range of wavelengths, where the first, second, and third ranges are at least partially nonoverlapping; and

a signal processor operatively associated with the detection system that combines an image signal representing locally maximum values of the first image signal with at least one of the second and third image signals to create a displayed image.

27. The enhanced vision system of claim 26, further comprising a controller that determines whether to combine the image signal representing locally maximum values of the first image signal with the second image signal, the third image signal, or both image signals.