NIGHT VISION TECHNOLOGY
( NIGHT VISION DEVICE )
Presented by:-
Shudhanshu agarwal
EC-11
WHAT WE WILL COVER!
 What is night vision
 Night vision approaches
 Working of night vision technology
 Night vision D...
Night Vision!!!
 Ability to see in dark environment
 Whether by biological or technological means, night vision
is possi...
Night Vision Approaches!!
 Spectral range
 Night-useful spectral range
techniques can sense radiation
that is invisible ...
Intensity range:
 Sufficient intensity range is simply the ability to
see with very small quantities of light.
 Many ani...
Working of night vision devices!!
Night vision technologies can be broadly divided into two main categories:
 Image inten...
1)IMAGE INTENSIFICATION !!!!
 This method of night vision amplifies the available light
to achieve better vision. An obje...
 Night vision goggles are electro-optical
devices that intensify existing light
instead of relying on a light source.
Ima...
2)THERMAL IMAGING!!!
WORKING OF THERMAL IMAGING!!!
 Infrared thermography, thermal imaging, and thermal video are examples
of infrared imaging...
Night Vision Devices!!!
 A night vision device (NVD) is an
optical instrument that allows
images to be produced in levels...
1) Night glasses
 Night glasses are
telescopes or binoculars
with a large diameter
objective. Large lenses can
gather and...
2) Thermal vision
 Thermal imaging cameras
are excellent tools for night
vision. They detect thermal
radiation and do not...
3) Image intensifier
 The image intensifier is a vacuum-tube based device
that converts visible light from an image so th...
Generations!!!!
 Generation 0
 Generation 1 (GEN I)
 Generation 2 (GEN II)
 Generation 3 (GEN III)
 Omnibus-VII (GEN ...
Generation 0
At that time infra-red was commonly called black light, a
term later restricted to Ultraviolet. It was not a ...
Generation 1 (GEN I)
 First generation passive devices, introduced during
the Vietnam War, were an adaptation of earlier
...
Generation 2 (GEN II)
 Second generation devices feature an improved image-
intensifier tube utilizing micro-channel plat...
Generation 3 (GEN III)
 Third generation night vision systems maintain the MCP from Gen II, but
now use a photocathode ma...
Omnibus-VII (GEN III+)
 GEN-III OMNI-VII devices can differ from standard Generation 3 in two
important ways. First, an a...
USAGE
Common applications for night vision include:
 Military
 Hunting
 Wildlife observation
 Security
 Navigation
 ...
THANK YOU
Night vision technology by shudhanshu agarwal
Night vision technology by shudhanshu agarwal
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Night vision technology by shudhanshu agarwal

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Night vision technology by shudhanshu agarwal

  1. 1. NIGHT VISION TECHNOLOGY ( NIGHT VISION DEVICE ) Presented by:- Shudhanshu agarwal EC-11
  2. 2. WHAT WE WILL COVER!  What is night vision  Night vision approaches  Working of night vision technology  Night vision Devices  Generation  Usage
  3. 3. Night Vision!!!  Ability to see in dark environment  Whether by biological or technological means, night vision is possible by combination of two approaches: sufficient spectral range, and sufficient intensity range  Human have poor night vision compared to many animals because the human eye does not have tapetum lucidum  Tapetum lucidum is a layer of tissue in the eye of many animals which improves vision in low night condition.
  4. 4. Night Vision Approaches!!  Spectral range  Night-useful spectral range techniques can sense radiation that is invisible to a human observer. Human vision is confined to a small portion of the electromagnetic spectrum called visible light. Enhanced spectral range allows the viewer to take advantage of non-visible sources of electromagnetic radiation (such as near-infrared or ultraviolet radiation).
  5. 5. Intensity range:  Sufficient intensity range is simply the ability to see with very small quantities of light.  Many animals have better night vision than humans do, the result of one or more differences in the morphology and anatomy of their eyes. These include having a larger eyeball, a larger lens, a larger optical aperture (the pupils may expand to the physical limit of the eyelids), more rods than cones (or rods exclusively) in the retina, and a tapetum lucidum.
  6. 6. Working of night vision devices!! Night vision technologies can be broadly divided into two main categories:  Image intensification  Image intensification technologies work on the principle of magnifying the amount of received photons from various natural sources such as starlight or moonlight.  Thermal imaging  Thermal imaging technologies work by detecting the temperature difference between the background and the foreground
  7. 7. 1)IMAGE INTENSIFICATION !!!!  This method of night vision amplifies the available light to achieve better vision. An objective lens focuses available light (photons) on the photocathode of an image intensifier. The light energy causes electrons to be released from the cathode which are accelerated by an electric field to increase their speed (energy level). These electrons enter holes in a micro channel plate and bounce off the internal specially-coated walls which generate more electrons as the electrons bounce through.
  8. 8.  Night vision goggles are electro-optical devices that intensify existing light instead of relying on a light source. Image intensifiers capture ambient light and amplify it thousands of times by electronic means to display the battlefield to a soldier via a phosphor display, hence why it becomes green. Green is a good choice for two reasons. One is that the phosphors, the things that glow and make the colour are relatively easy to make it green. And because the eye is more sensitive to green light than virtually any other wavelength, it means that you can make your display dimmer than any other wavelength and your eye will be sensitive to it.
  9. 9. 2)THERMAL IMAGING!!!
  10. 10. WORKING OF THERMAL IMAGING!!!  Infrared thermography, thermal imaging, and thermal video are examples of infrared imaging science.  Thermal imaging cameras detect radiation in the infrared range of the electromagnetic spectrum (roughly 9000–14,000 nanometers or 9–14 µm) and produce images of that radiation, called thermo grams. Since infrared radiation is emitted by all objects above absolute zero according to the black body radiation law, thermography makes it possible to see one's environment with or without visible illumination.  When viewed through a thermal imaging camera, warm objects stand out well against cooler backgrounds; humans and other warm-blooded animals become easily visible against the environment, day or night. As a result, thermography is particularly useful to military and other users of surveillance cameras.
  11. 11. Night Vision Devices!!!  A night vision device (NVD) is an optical instrument that allows images to be produced in levels of light approaching total darkness.  They are most often used by the military and law enforcement agencies, but are available to civilian users.  The term usually refers to a complete unit, including an image intensifier tube, a protective and generally water-resistant housing, and some type of mounting system.
  12. 12. 1) Night glasses  Night glasses are telescopes or binoculars with a large diameter objective. Large lenses can gather and concentrate light, thus intensifying light with purely optical means and enabling the user to see better in the dark than with the naked eye alone
  13. 13. 2) Thermal vision  Thermal imaging cameras are excellent tools for night vision. They detect thermal radiation and do not need a source of illumination. They produce an image in the darkest of nights and can see through light fog, rain and smoke.
  14. 14. 3) Image intensifier  The image intensifier is a vacuum-tube based device that converts visible light from an image so that a dimly lit scene can be viewed by a camera or the naked eye. While many believe the light is "amplified," it is not.
  15. 15. Generations!!!!  Generation 0  Generation 1 (GEN I)  Generation 2 (GEN II)  Generation 3 (GEN III)  Omnibus-VII (GEN III+)
  16. 16. Generation 0 At that time infra-red was commonly called black light, a term later restricted to Ultraviolet. It was not a success due to its size and cost. They were active devices, using a large infrared light source to illuminate targets. Their image intensifier tubes function using an anode and an S-1 photocathode, made primarily of silver, cesium, and oxygen and a electrostatic inversion with electron acceleration were used to achieve gain.
  17. 17. Generation 1 (GEN I)  First generation passive devices, introduced during the Vietnam War, were an adaptation of earlier active GEN 0 technology, and rely on ambient light instead of an infrared light source. Using an S-20 photocathode, their image intensifiers produce a light amplification of around 1,000×, but are quite bulky and require moonlight to function properly.  Examples:  AN/PVS-2 Starlight scope
  18. 18. Generation 2 (GEN II)  Second generation devices feature an improved image- intensifier tube utilizing micro-channel plate (MCP) with an S-25 photocathode, resulting in a much brighter image, especially around the edges of the lens. This leads to increased illumination in low ambient light environments, such as moonless nights. Light amplification is around 20,000×. Also improved were image resolution and reliability.  Examples:  AN/PVS-4  AN/PVS-5  SUPERGEN
  19. 19. Generation 3 (GEN III)  Third generation night vision systems maintain the MCP from Gen II, but now use a photocathode made with gallium arsenide, which further improves image resolution. In addition, the MCP is coated with an ion barrier film for increased tube life. The light amplification is also improved to around 30,000–50,000×.Power consumption is higher than GEN II tubes.  Examples:  AN/PVS-7  AN/NVS-7  AN/PVS-10  AN/PVS-14  AN/PNVS-14
  20. 20. Omnibus-VII (GEN III+)  GEN-III OMNI-VII devices can differ from standard Generation 3 in two important ways. First, an automatic gated power supply system regulates the photocathode voltage, allowing the NVD to instantaneously adapt to changing light conditions. The second is a removed or greatly thinned ion barrier. The disadvantage to a thin or removed ion barrier is the overall decrease in tube life from a theoretical 20,000 hrs mean time to failure (MTTF) for Gen III type, to 15,000 hrs MTTF for GEN IV type. However, this is largely negated by the low number of image intensifier tubes that reach 15,000 hrs of operation before replacement.  Examples:  AN/PVS-22  NVS-22
  21. 21. USAGE Common applications for night vision include:  Military  Hunting  Wildlife observation  Security  Navigation  Hidden-object detection  Entertainment
  22. 22. THANK YOU

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