NIGHT VISION TECHNOLOGY…..see in darkness

SVISTPresented by:

D RAJESH11W51A0211

Deprt. Of Electrical and Electronics Engineering

S PURUSHOTHAM REDDY11W51A0239

CONTENTS

INTRODUCTIONTYPES OF NIGHT VISIONWORKING PRINCIPLE IMAGE INTENSIFIERTHERMAL IMAGINGNIGHT VISION DEVICESGENERATIONSAPPLICATIONSCONCLUSION

INTRODUCTION

Night vision technology allows one to see in darkness.

It is mainly developed for military surveillance.

We can see a person standing over 180 m distance in a moonless and cloudy night.

It plays a key role in search and rescue operations.

TYPES OF NIGHT VISION

Biological night vision:

Molecules in the rods of the eye undergo a change in shape according to the light.

Molecules in the human rods is insensitive to the light

Technical night vision:

Image intensifier

Thermal Imaging

WORKING PRINCIPLEImage Intensifier:

Night vision amplifies light to a better vision.

A convention lens will capture completely envelops the surrounding light.

The gathered light is sent to the image intensifier-tube.

In each channel there release thousands of electrons.

Electrons collide with each other and produce more.

The new atoms again collide and creates a chain.

These electrons after hitting a screen will produce photons and create a green image.

This green phosphor image is viewed through lens

CONTI….

THERMAL IMAGING In order to understand thermal imaging, it is important to

understand something about light.

CONTI….Three Types of IR rays:

Near Infrared:

Closest to visible light, near – IR has wavelengths that range from 0.7 to 1.3 microns.

Mid Infrared:

Mid – IR has wavelengths ranging from 1.3 to 3 microns.

Thermal Infrared:

Thermal infrared the largest part of the infrared spectrum, thermal – IR has wavelengths ranging from 3 microns to over 30 microns.

THERMAL IMAGING PROCESS:All objects emit infrared energy a function as a function of their temperature

All objects emit infrared energy a function as a function of their temperature

A lens will focuses the infrared light.

The focused light is scanned and create temperature pattern

The pattern is translated into electric impulses.

The impulses sent to an electrical circuit board that translates the information into the data to display

The signal processing unit sends the information and it appears in different colors.

Generally thermal images are black and white in nature.

NIGHT VISION DEVICESNight vision device can be split into three categories

SCOPESThey are monocular normally handheld or mounted on a weapon GOGGLESThe night vision binocular and worn on the head

CAMERASUsed for transmission or recording images mostly if the location is fixed

GENERATIONS Generation 1:

In 1950’s devices based on vacuum tube technology are available.

Generation 2:

The vacuum tubes are simplified to single stage in 2nd generation.

Generation 3:

The third generation night vision devices advanced in using small electronic circuits

Generation 4:

In present generation the researches are being made to bring it into the micro electron chips.

APPLICATIONS

Military surveillance

Wild life observation

CONTI….

Hidden Object

Detection

Property management-Security surveillance

CONCLUSION In present scenario night vision the applications of night

vision technology is very essential to combat terrorism which is the major problem faced by the mankind.

After a long journey from 1950’s we have much developed night vision technology but it is limited in use.

It will yield good results in future if we use it in every field for defensive purpose.

Any

Queries