1. NIGHT VISION
TECHNOLOGY

2. Introduction
 Night vision is used to locate an object which is 200 yards away
even in moonless, cloudy night
 Night vision can work into two different ways, depending on the
technology used
 They are image enhancement and thermal imaging. Image
enhancement works by collecting lower portion of infrared light
spectrum
 Thermal imaging operates by capturing the upper portion of the
infrared light spectrum

3. TYPES OF NIGHT VISION
It is broadly classified into two types
 Biological Night Vision
 Molecules in the rods of the eye undergo a change in shape
as light.
 Molecules in the human rods is insensitive to the light.
 Technical Night Vision
 Image intensifier
 Thermal imaging

4. Technical Night Vision
 Image Intensifier
 Night vision amplifies light to achieve 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.
 These electrons enter micro channel plate and bounce off and generate more
electron.
 Thousands of other electrons to be released in each channel.
 Original electrons collide with the channel , exciting atoms and causing other
electrons.
 New electrons collide with other atoms, creating a chain.


5. Technical Night Vision (cont..)
 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. Technical Night Vision (cont..)
 Thermal Imaging
All objects emit infrared energy as a function of their temperature.
 A lens focuses the infrared light.
 The focused light is scanned and create temperature pattern.
 The pattern created is translated into electric impulses.
 The impulses are sent to a circuit board that translates the
information into data for the display.

7. Technical Night Vision (cont..)
The signal-processing unit sends the information to the is play, and
appears as various colors.
Thermal images are black and white in nature.

8. NIGHT VISION DEVICES
Night vision devices are basically divided into three categories
 SCOPES
 They are monocular normally
handheld or mounted on a weapon.
GOGGLES
 They are binocular and
worn on the head.
CAMERAS
 Used for transmission or recording
of images mostly if the location is fixed.

9. GENERATIONS
Generation 0
The earliest (1950's) night vision products were based
on image conversion, rather than intensification.
Generation 1
 Vacuum Tube Technology
 Full Moon Operation
 Amplification: 1,000
 Operating Life: 2,000 Hours

10. GENERATIONS (cont..)
Fig:- Generations1 Night vision
Sources: http://www.nightvision.com

11. GENERATIONS (cont..)
 Fiber optic plates collimate incoming light before impacting a
photo cathode which releases electrons, which in turn impact a
phosphor screen
 The excited screen emits green light into a second fiber optic
plate, and the process is repeated
 The complete process is repeated three times providing an overall
gain of 10,000

12. GENERATIONS (cont..)
Generation 2
 First Micro channel Plate Application
 One-Quarter Moon Operation
 Amplification: 20,000
 Operating Life: 2,500 Hours
Generation3
 Improved Micro channel Plate & Photocathode
 Starlight Operation
 Amplification: 40,000
 Operating Life: 10,000 Hour

13. GENERATIONS (cont..)
Fig:- Generations2 Night vision device
Sources: http://www.nightvision.com

14. GENERATIONS (cont..)
 In second-generation night visions the addition of the micro
channel plate (MCP) collimated electron flow and increased the
light-amplification gain Current image intensifiers incorporate
their predecessor's resolution with additional light amplification
 The multi alkali photo cathode is replaced with a gallium arsenide
photocathode; this extends the wavelength sensitivity of the
detector into the near infrared
 The moon and stars provide light in these wavelengths, which
boosts the effectively available light by approximately
30%, bringing the total gain of the system to around 30,000

15. Applications
Military
Law enforcement
Hunting
Wildlife observation
Surveillance
Security
Navigation
Hidden-object detection
Entertainment

16. CONCLUSIONS
 Night vision devices are basically designed for utmost
defensive purposes but the application within the
scientific or the civilian range is often prohibited by
law.
 In present scenario the applications of night vision
technology is very essential to combat terrorism
which is a major problem being faced by mankind.
 It is mainly used in military purposes as well as navigation
, surveillance and targeting .
 Night vision is used to locate an object which is 200 yards
away even in moonless , cloudy night

17. References

18. Thank you!