Ppt

Night Vision Technology

By: Nikita Bansal

Introduction

Night vision technology has shaped history.

Pre 1940’s: Flares and spot lights were used for operations at night.

Introduction

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.

Introduction

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A tank from World War II

equipped with a search light used for night

combat.

Early Development

The night vision devices (NVD) were first created during WW II.

Functioned by placing an infrared filter over a searchlight.

Fighters would use special binoculars to see using the light from the searchlights.

Many problems came from this night vision method.

Basics Of Night Vision

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.

Infrared Spectrum

Near- Infrared Mid-InfraredThermal- Infrared

Spectrum

Difference between thermal IR and other two is : Thermal - IR is emitted by an object instead of reflected off it.Infrared light is emmited by an object because of what is happening at atomic level.

How Night Vision Works?

Technology Used

Thermal imaging (infrared)

Image enhancement(light amplification)

Thermal Imaging

Infrared light emitted by all objects

Temperature pattern created called a thermogram and

translated into electric impulses Information sent to the display

unit

Thermal Imaging

The basic components of a thermal-imaging system

Image Enhancement

Also called night-vision devices (NVDs)

a special tube, called an image-intensifier tube, to collect and amplify infrared and visible light.

ambient light and some near-infrared light captured

Image Enhancement

Image-intensifier tube changes photons to electrons and back again.

The image-intensifier tube changes photons to electrons and back again.

Generations

Generation 0

• based on image conversion, rather than intensification, required a source of invisible infrared (IR) light to illuminate the target area.

Generation 1

• had three image intensifier tubes connected in a series

Generations

Generation 2

• image intensification significantly increased gain and resolution by employing a micro-channel plate(MCP) that was light weight, and more effective at focusing light into clear images

Generation 3

• gallium arsenide (GaAs) photocathode and the ion-barrier film on the MCP

Current Generations

The currently generations of NVS are generations 3 and 4.

Generation 3 is much like generation 2 except for it has a substantially longer life, as well as more defined images.

Generation 4 has less noise than generation 3, however it has shorter life.

Current Generations Cont.

Here is a chart comparing the life in hours of the intensification tube for generations 1-3

Generation 1 Generation 2 Generation 3

2,000 hours 2,500- 4,000 hours

10,000 hours

Characteristics of Night Vision

Textures, Light and Dark - Objects that appear light during the day but have a dull surface may appear darker, through the night vision unit, than objects that are dark during the day but have a highly reflective surface.

Night vision does not present normal depth perception.

Characteristics of Night Vision

Fog and Rain - the light reflecting off of fog or heavy rain causes much more light to go toward the night vision unit and may degrade its performance.

Honeycomb - This is a faint hexagonal pattern which is the result of the manufacturing process.

Characteristics of Night Vision

Black Spots - A few black spots throughout the image area are also inherent characteristics of all night vision technology. These spots will remain constant and should not increase in size or number.

Night-vision equipments

Devices

Scopes Goggles Cameras

Night-vision equipments

Scopes - handheld or mounted on a weapon, scopes are monocular

Night-vision equipments

Goggles - worn on the head, goggles are binocular (two eye-pieces), excellent for constant viewing

Night-vision equipments

Cameras - can send the image to a monitor for display or to a VCR for recording

How do night vision goggles work

General Public Use

Development of NVD up until the 1980’s was completely focused around military purposes.

In the 80’s, companies in the US and Europe took NVT and found ways to improve everyday civilian life.

General Public Use

Military

Law Enforcement

This soldier is using DARK

Security INVADER night-vision goggles

NavigationHidden-object detectionEntertainment

General Public Use Cont.

Wildlife observation

Hunting

Surveillance

General Public Use Cont.

Security

Navigation

Hidden-Object detection

Entertainment

Conclusion

In conclusion I believe that is wonderful how something originally designed for destruction, can now help people on an every-day basis.

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