Night vision technology allows one to see in low-light or no-light conditions. There are two types: biological night vision in human eyes, and technical night vision using image intensifiers or thermal imaging. Image intensifiers work by amplifying ambient light captured and accelerating electrons to create a visible image, while thermal imaging detects infrared light emitted as heat. Night vision has advanced through generations with better amplification and resolution, and is used for military, security, hunting and wildlife applications.

2.  CONTENTS :
Introduction
Types of Night Vision
Working of Technical Night Vision
Night Vision Devises
Generations
Applications
Advantages
Disadvantages
Conclusion

3.  Introduction
• Night Vision Technology, literally allows one to see in the dark.
• It is originally developed for military use.
• With poor night vision equipment, we can see a person standing over 200
yards(183 m) away on a moonless, cloudy night.

4.  Types of night vision
It is broadly classified into two types
I. Biological night vision
 Molecules in the rods of the eye undergo a change in shape as a
light.
 Molecules in the human rods is insensitive to the light.
II. Technical night vision
 Image Intensifier
 Thermal imaging

5. Working of technical night vision
Image intensifier
 Night vision amplifies light to achive better vision.
 A conventional lens,captures ambient light.
 The gathered light is sent to the image-intensifier tube.
 The light energy released electron from the cathode and accelerated,
In image-intensifier tube, the electrons hit a screen.
 The energy of the electrons release photons and create green image
on the screen.
 The green phosphor image is viewed through another lens.

6. Image intensifier process

7.  Thermal imaging
All objects emit infraded energy as a function of their temperature.
 A lens focuses the infraded light.
 A focused light is scanned and create temperature pattern.
 The pattern created is translated into electron impulses.
 The impulses are sent to a circuit board that translate the
information into data for the display.
 Thermal images are black and white in nature.

8. Thermal imaging process

9. Night vision devices
Night vision devices basically devided into three categories.
SCOPES
• They are Monculer normally handeled or mounted on a weapon.

10.  GOGGLES
• They are binocular and worn on the head.

11.  CAMERAS
• Used for transmission or recording of images mostly if the location is
fix.

12. Generations
Generation 0:
The earlist (1950’s) Night Vision products were based on image
conversion, rather than intensification.
Generation 1
• Vacuum tube
• Full moon operation
• Amplification : 1,000
• Operating life : 2,000 hours

13. Generation 1

14.  Generation 2
• First micro channel plate application
• One-quarter moon operation
• Amplification : 20,000
• Operating Life : 2,500 Hours

15. Generation 2

16.  Generation 3
• Improved micro channel plate and photocathod
• Starlight Operation
• Amplification : 40,000
• Operating Life : 10,000 Hours

17. Applications
• Military
• Hunting
• Wildlife observation
• Security
• Hidden-object detection

18. Advanteges
• No particular skill is required.
• Accident cases reduction.
• Compact system
• 3X range visual

19. Disadvanteges
• The only disadvantages is that the inifial cost too high.

20. Conclusion
• Today in the 21`st century we have come a long way in the
development of night vision technology
from the early 1940’s.
• Night vision devices are basically designed for utmost
defensive purposes.
• In present scenario the applications of night vision
technology is very essential to combat terrorism which is a
major problem being faced by mankind.