IT IS VERY HELPFULL IN NIGHT IN THE FIELD OF SURVILLEANCE, MILITARY, LASER GUNS AND SO ON...

1. BY
ASHUTOSH KUMAR

2. Content
 Introduction
 Basics
 Thermal Imaging
 Image Enhancement
 Generations
 Night Vision Devices
 Applications
 Advantages
 Disadvantages
 Conclusion

3. Introduction
 The word “Night vision” itself means the ability to see
objects in low light conditions.
 Humans have poor night vision compared to many other
animals.
 With the proper night vision equipment , we can see a
person standing 200 yards (183 m) on a moonless or
cloudy night.

4. Basics
 In order to understand night vision ,it is important to
understand something about light.
 The amount of energy in a light wave is related to its
wavelength.
 Just next to visible light spectrum is the infrared
spectrum.

5.  Infrared can be split into three categories:
1. near-infrared
2. Mid-infrared
3. Thermal-infrared
 Infrared light is emitted by an object because of what is
happening at atomic level.

6. Thermal Imaging
 A special lens focuses the infrared light emitted by all the
objects in view.
 The focused light is scanned by a phased array of infrared
detector elements.
 The detector element creates a very detailed temperature
pattern called Thermogram.
 The thermogram created by detector elements is
translated into electrical impulses.
 The impulses are sent to signal processing unit

7.  The signal processing unit sends the information to
display. The combination of all the impulses from all of
the elements create the image.

8. Image Enhancement
 A conventional lens, called the objective lens captures
ambient light and some near-infrared light.
 The gathered light is sent to image intensifier tube.
 The image intensifier tube consists of :
1. Photocathode
2. Micro Channel Plate (MCP)
3. Phosphors coated screen

9. Fig : Image Enhancement

10. Generations
 Generation 0 :
The earliest (1950’s) night vision products were based on
image conversion , rather than intensification
 Generation 1 :
1. Vacuum tube technology
2. Full moon operation
3. Amplification : 1,000
4. Operating life : 2,000 Hours

11. Fig : Generation 1 night vision device

12.  Generation 2 :
1. First Micro Channel Plate operation
2. One-quarter moon operation
3. Amplification : 20,000
4. Operating life : 2,500 Hours
 Generation 3 :
1. Improved Micro Channel Plate & Photocathode
2. Starlight operation
3. Amplification : 40,000
4. Operating life : 10,000 Hours

13. Fig : Generation 2 night vision device

14. Night Vision Devices
 Night vision devices are basically divided into three
categories:
 Scopes : They are monocular normally handheld or
mounted on a weapon.

15.  Goggles : They are binocular and worn on the head.
 Cameras : Used for transmission and recording.

16. Applications
 Military
 Wildlife observation
 Hunting
 Surveillance
 Security
 Hidden object detection

17. Advantages
 Distant vision is possible.
 Detection of objects in absolute darkness.
 Less affected by temperature variations.

18. Disadvantages
 The image has low contrast and poor resolution.
 Do not see the target through transparent obstacles.
 High cost

19. Conclusion
 Today in the 21st century we have come a long way in the
development of night vision technology, from the early
1940s.
 In present scenario the applications of night vision
technology is very essential to combat terrorism which is
a major problem being faced by mankind.

20. Thank you