Night Vision Tech Ppt Deepika

8/2/2019 Night Vision Tech Ppt Deepika

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NIGHT VISION

TECHNOLOGY

BYTushar choudhary

TT-CS



NIGHT VISION TECHNOLOGY

IntroductionTypes of NVT

Thermal Imaging

Image EnhancementPerformance Attributes

Technical characteristics

EquipmentsApplications

Conclusion

References



Introduction

NVT allows us to see in the dark

Originally developed for military use

Now used for site security, surveillance

as well as search and rescueEvolved from bulky optical instruments

in lightweight goggles through theadvancement of image intensificationtechnology.



Types of night vision

Categorized by generations

Each substantial change NVTestablishes a new generation

Categorized into:Generation-0

Generation-1

Generation-2Generation-3

Generation-4



Generation-0

Created by US Army Uses active infrared A projection unit called IR illuminator

is attached

Full moon operation Use anode in conjunction with cathode

to accelerate the electrons Problems –acceleration causes

distortion of image as well asreduction of life of the tube Also, it was quickly duplicated by the

hostile nations



Figure illustrates Generation 1Night vision technology.



Generation-1 (1960’s)

Uses passive infrared

Uses ambient light provided by the moonand the stars

Don’t require a source of projectedinfrared light

Don’t work well on cloudy or moonlessnights

One quarter moon operation

Uses same image-intensifier tubetechnology as Generation-0

Same problems as faced by the

Generation-0



Figure illustrates Generation 2Night vision technology.




Offer improved resolution andperformance over Generation-1 devices

Considerably more reliable

Able to see in extreme low lightconditions due to the addition ofmicrochannel plate(MCP) to the image-intensifier tube

The images are less distorted andbrighter




Currently used by the US Army

Better resolution and sensitivity

Photocathode is made up of Gallium

ArsenideMCP is coated with an ion barrier

Tube life is increased




Known as “filmless and gated”technology

Shows significant improvement in bothhigh- and low-level light environments

No ion barrier in MCP

Responds quickly to different lightningconditions

Reduced background noise

Enhances signal to noise ratio

Images are less distorted and brighter



Thermal imaging This technology operates by capturing

upper portion of the infrared lightspectrum, which is emitted as heat

Hotter objects emit more of this lightthan the cooler objects

These elements then create athermogram

Thermogram electric pulses display

data



The basic components of aThermal-imaging system



Thermal imaging

Thermal imaging lets you see again.

It is quite easy to see everythingduring the day...

...but at night, you can seevery little.



Thermal imaging devices

Two types:

1. Uncooled.

2. Cryogenically cooled.

Great for detecting people or

working in near-absolutedarkness



Image Enhancement



Image Enhancement

It is also known as Image intensification

Relies on image intensifier tube to collectan amplify infrared and visible light

Lens captures the light which is then sentto image intensifier tube

It has photocathode that converts photonsinto electrons

When electrons pass through MCP ,moreelectrons are presented

This causes chain reaction where atomsare released

Electrons reach phosphor screen andphotons are released

Those phosphor create green image



Sensitivity (photo response)- tube’sability to detect the available light

Signal- plays a key role in night

vision’s performance

Resolution- ability to dissolve detailin the image

Performance Attributes



Technical Characteristics

Textures, Light and Dark

Depth Perception

Fog and RainHoneycomb

Spots



Equipments

Three categories

Scopes

Goggles

Cameras



Scopes- monocular, handheld,better look at a specific object andthen return to normal viewing

conditions.Goggles- binocular, handheld or

worn, excellent for constantviewing

Cameras- send the image to amonitor for display or to a VCR forrecording.

Equipments



DARK INVADER Multi-purpose Pocketscope

DARK INVADER Night-vision Goggles 4501



Stealth 301 Series Day/Night Video Camera

Camcorders are a fast-growing segment of the night-vision industry.



Soldiers using

DARK INVADER night-vision Goggles.



Military

Law enforcement

Hunting

Wild life observationSurveillance

Security

Navigation

Hidden-object detection

Entertainment

Applications



Conclusions

Although the term ``night vision''currently encompasses threedistinct technologies, it is the

evolution of image intensificationtechnology that first made devicespractical and widely used.

Their success was the result ofadvancements in light amplificationand resolution techniques.





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Night Vision Tech Ppt Deepika

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