Night vision technology

3.  What is night vision
 History
 Working of night vision device
 Generations
 Usage
 References

5.  The word ‘Night vision’ itself means the
ability to see in low light conditions.
 Humans have poor night vision compared to
many other animals.

6.  So we all might have a question in our mind that is this
really possible to see in the dark night?
 The answer is……..YES, we can see in the dark night
using the proper equipment made by using this
technology.
 We can see a person standing over 183m(200 yards)
away in the dark night.

7.  Pre 1940’s: Flares and spotlights were used for
operations at night.
 Due to the nature of these early night vision devices
(NVD), they gave away tactical positions.
 Military scientists began to think of ways to improve
night vision to gain a strategic advantage

9.  The night vision is possible because of two
approaches:
(1) Sufficient spectral range
(2) Sufficient intensity range.
 Two technologies are used for night vision:
(1)Thermal Imaging
(2)Image Intensification

10.  Infrared light is used to visualize the things in the dark.
 The amount of energy in a light wave is related to its
wavelength: Shorter wavelengths have higher energy.
 Of visible light, violet has the most energy, and red has the
least.
 Just next to the visible light spectrum is the infrared
spectrum.

15. 1.A special lens focuses the infrared light emitted by
all of the objects in view.
2.The focused light is scanned by a phased array of
infrared-detector elements. The detector elements
create a very detailed temperature pattern called a
thermogram. It only takes about one-thirtieth of a
second for the detector array to obtain the
temperature information to make the thermogram.
3.The thermogram created by the detector elements
is translated into electric impulses.
4.The impulses are sent to a signal-processing unit,
a circuit board with a dedicated chip that translates
the information from the elements into data for the
display.
5.The signal-processing unit sends the information
to the display, where it appears as various colors
depending on the intensity of the infrared
emission.
6.The combination of all the impulses from all of
the elements creates the image.

16.  NVDs have been around for more than 50
years. They are categorized by generation.
 Each substantial change in NVD technology
establishes a new generation.

17.  Created by US Army.
 Uses active infrared.
 A projection unit called IR illuminator is attached with
NVD.
 Use anode in conjunction with cathode to accelerate
the electrons.
 Problems : acceleration causes distortion of image and
reduction of the life of the tube.

18.  Uses passive infrared.
 Uses ambient light provided by the moon and the
stars.
 Doesn’t work well on cloudy or moonless nights.
 Uses same image-intensifier tube technology as
Generation-0.
 Same problems as faced by the Generation-0.

19.  Offer improved resolution and performance over
Generation-1 devices.
 Considerably more reliable.
 Able to see in extreme low light conditions due to the
addition of microchannel plate(MCP) to the image-
intensifier tube.
 The images are less distorted and brighter.

20.  Currently used by the US Army.
 Better resolution and sensitivity.
 Photocathode is made up of Gallium Arsenide-
efficient of converting photons to electrons.
 Tube life is increased

21.  Shows significant improvement in both high- and low-
level light environments.
 No ion barrier in MCP.
 Reduced background noise.
 Enhances signal to noise ratio.
 Images are less distorted and brighter.

22. It can be splitted in three broad categories:
 Scopes
 Goggles
 Cameras

26.  Military
 Hunting
 Wildlife observation
 Surveillance
 Security
 Hidden-object detection
 Entertainment

27.  An increase in nighttime situational awareness for
pilots.
 This would markedly decrease the possibility of
collisions with terrain or man-made obstructions.
 It does permit the user to see objects that normally
would not be seen by the unaided eye.

28.  Lack of color discrimination.
 Neck strain and fatigue.
 High initial cost to purchase.
 Require on-going maintenance.
 Need for recurrent training.
 Decreased field of aided view .

29. .
BMW's Night Vision with
Pedestrian Detection system
allows drivers to see what (or
who) is down the road -- even
on the darkest nights.

32.  http://en.wikipedia.org/wiki/Night_vision
 http://electronics.howstuffworks.com