NIGHT VISION TECHNOLOGYNIGHT VISION TECHNOLOGY ((Night Vision DeviceNight Vision Device) )

PROJECT GUIDE: ANUSH

PRESENTED BY: SANKETH

WHAT WE WILL COVER !WHAT WE WILL COVER ! What is night vision What is night vision Types of night visionTypes of night vision Night vision approachesNight vision approaches The night vision technology The night vision technology Working of night vision device Working of night vision device GenerationsGenerations ApplicationsApplications ConclusionConclusion ReferencesReferences

It is quite easy to see everything during the day...

But at night, we can see very little.

Night Vision device lets us see again

What is Night Vision ??What is Night Vision ?? Ability to see in dark environmentAbility to see in dark environment Whether by biological or technological means, night vision Whether by biological or technological means, night vision

is made possible by a combination of two approaches: is made possible by a combination of two approaches: sufficient spectral range, and sufficient intensity rangesufficient spectral range, and sufficient intensity range . .

Humans have poor night vision compared to many animals, Humans have poor night vision compared to many animals, in part because the human eye does not have a tapetum in part because the human eye does not have a tapetum lucidumlucidum

The The tapetum lucidumtapetum lucidum(Latin: "bright tapestry", plural (Latin: "bright tapestry", plural tapeta lucidatapeta lucida) is a layer of tissue in the eye of many ) is a layer of tissue in the eye of many animals, that lies immediately behind or sometimes within animals, that lies immediately behind or sometimes within the retina. It reflects visible light back through the retina, the retina. It reflects visible light back through the retina, increasing the light available to the photoreceptors. increasing the light available to the photoreceptors.

This improves vision in low-light conditions.This improves vision in low-light conditions.

Types of Night VisionTypes of Night Vision

Be it biological or technical it based on two Be it biological or technical it based on two Night Vision Approaches-Night Vision Approaches-

(i)Spectral range(i)Spectral range

(ii)Intensity range(ii)Intensity range

Depending upon the way it is implemented Depending upon the way it is implemented it is broadly classified into two typesit is broadly classified into two types

(i) Biological Night vision(i) Biological Night vision (ii) Technical Night vision(ii) Technical Night vision

Night Vision ApproachesNight Vision Approaches Spectral range :Spectral range : Night-useful spectral range Night-useful spectral range

techniques make the viewer techniques make the viewer sensitive to types of light that sensitive to types of light that would be invisible to a human would be invisible to a human observer. Human vision is observer. Human vision is confined to a small portion of the confined to a small portion of the electromagnetic spectrum called electromagnetic spectrum called visible light. Enhanced spectral visible light. Enhanced spectral range allows the viewer to take range allows the viewer to take advantage of non-visible sources advantage of non-visible sources of electromagnetic radiation (such of electromagnetic radiation (such as near-infrared or ultraviolet as near-infrared or ultraviolet radiation). Some animals can see radiation). Some animals can see well into the infrared and/or well into the infrared and/or ultraviolet compared to humans, ultraviolet compared to humans, enough to help them see in enough to help them see in conditions humans cannot.conditions humans cannot.

Intensity range :Intensity range :

Sufficient intensity range Sufficient intensity range is simply the ability to see with very small is simply the ability to see with very small quantities of light. Although the human visual quantities of light. Although the human visual system can, in theory, detect single photons system can, in theory, detect single photons under ideal conditions, the neurological noise under ideal conditions, the neurological noise filters limit sensitivity to a few tens of photons filters limit sensitivity to a few tens of photons even in ideal conditions.even in ideal conditions.Many animals have better night vision than Many animals have better night vision than humans do, humans do, Enhanced intensity range is achieved via Enhanced intensity range is achieved via technological means through the use of an technological means through the use of an image intensifier, or other very low-noise and image intensifier, or other very low-noise and high-sensitivity array of photo detectors.high-sensitivity array of photo detectors.

Why do NVD devices Why do NVD devices always show images always show images in hues of green?in hues of green?

The image is green because the phosphor is green in colour that is good for human eye to pick up detail

A tank from World War II equipped with A tank from World War II equipped with a search light used for night combat.a search light used for night combat.

Night Vision DeviceNight Vision Device A A night vision devicenight vision device

(NVD) is an optical (NVD) is an optical instrument that allows instrument that allows

images to be produced in images to be produced in levels of light levels of light approaching total approaching total darkness.darkness.

They are most often used They are most often used by the military and law by the military and law enforcement agencies,enforcement agencies,

but are available to but are available to civilian users.civilian users.

The figure shows night The figure shows night vision gogglevision goggle

EXAMPLEEXAMPLES :S :1. 1. the AN/PVS-14 is the AN/PVS-14 is

a monocular night a monocular night vision device in vision device in use with the US use with the US military as well as military as well as by civilians. It by civilians. It may be mounted may be mounted on the user's head on the user's head for handsfree use for handsfree use with a harness or with a harness or helmet helmet attachmentattachment

2.2. Another example is binoculars Another example is binoculars night vision device.night vision device.

Binocular telescopesBinocular telescopes, or , or binocularsbinoculars (also known as field (also known as field glasses), are two identical or glasses), are two identical or mirror-symmetricalmirror-symmetrical

telescopes mounted side-by-side telescopes mounted side-by-side and aligned to point accurately and aligned to point accurately in the same direction, allowing in the same direction, allowing the viewer to use both eyes the viewer to use both eyes (binocular vision) when viewing (binocular vision) when viewing distant objects.distant objects.

3.3.

Another Example Another Example is monocular is monocular situated on the situated on the gun. The figure gun. The figure shows this type shows this type of night vision of night vision devicedevice

Working of Night Vision Working of Night Vision devicesdevices

Night Vision Night Vision technology technology consists of two consists of two major types: major types:

image image intensification intensification (light (light amplification) and amplification) and

Thermal Thermal imaging(infrared).imaging(infrared).

IMAGE IMAGE INTENSIFICATIONINTENSIFICATION

It is also called light amplificationIt is also called light amplification It is less expensive than thermalIt is less expensive than thermal Light amplification technology takes Light amplification technology takes the small amount of light, such as the small amount of light, such as moonlight or starlight, that is in the moonlight or starlight, that is in the surrounding area, and converts the surrounding area, and converts the light energy (scientists call it photons), light energy (scientists call it photons), into electrical energy (electrons)into electrical energy (electrons) These electrons pass through a thin These electrons pass through a thin disk that's about the size of a quarter disk that's about the size of a quarter and contains over 10 million channels.and contains over 10 million channels. As the electrons travel through and As the electrons travel through and strike the walls of the channels, strike the walls of the channels, thousands more electrons are released. thousands more electrons are released. These multiplied electrons then These multiplied electrons then bounce off of a phosphor screen which bounce off of a phosphor screen which converts the electrons back into converts the electrons back into photons and lets you see an impressive photons and lets you see an impressive nighttime view even when it's really nighttime view even when it's really dark. dark.

All image All image intensified intensified night vision night vision products on the products on the market today market today have one thing have one thing in common: in common: they produce a they produce a green output green output imageimage

PARTS OF NIGHT VISION PARTS OF NIGHT VISION DEVICEDEVICE

1.1. Image intensifier tubeImage intensifier tube

2.2. Phosphor screenPhosphor screen

3.3. Objective lensObjective lens

4.4. Infrared illuminatorInfrared illuminator

THERMAL THERMAL IMAGINGIMAGING

WORKING OF THERMALWORKING OF THERMAL IMAGINGIMAGING This method do not require any ambient light at all.This method do not require any ambient light at all. principle -: principle -: All objects emit infrared energy as a All objects emit infrared energy as a

function of their temperature.function of their temperature.

1.1. A special lens focuses the infrared light emitted by A special lens focuses the infrared light emitted by all of the objects in view. all of the objects in view.

2.2. The focused light is scanned by a phased array of The focused light is scanned by a phased array of infrared-detector elements. These create detailed infrared-detector elements. These create detailed temperature pattern called a temperature pattern called a thermogramthermogram..

3.3. The thermogram created by the detector elements The thermogram created by the detector elements is translated into electric impulses. is translated into electric impulses.

4.4. The impulses are sent to a circuit board with a The impulses are sent to a circuit board with a dedicated chip that translates the information from dedicated chip that translates the information from the elements into data for the display. 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 infrared emission.

6. Thermal images are normally black and white in nature, where black objects are cold and white objects are hot.

7. Some thermal cameras show images in color. This false color distinguishes between objects at different temperatures

TYPES OF THERMAL TYPES OF THERMAL IMAGING DETECTORSIMAGING DETECTORS

1.1. Un-cooled Infrared Detector:Un-cooled Infrared Detector: Common typeCommon type The infrared-detector elements are contained The infrared-detector elements are contained

in a unit that operates at room temperature. in a unit that operates at room temperature. Bulky in size.Bulky in size.

2.2. Cooled Infrared Detector:Cooled Infrared Detector: Expensive and susceptible to damage.Expensive and susceptible to damage. infrared-detector elements are sealed inside infrared-detector elements are sealed inside

a container that cools them to below 32 F .a container that cools them to below 32 F . cooled systems can see a distance more than cooled systems can see a distance more than

1,000 ft (300 m) away. 1,000 ft (300 m) away.

Un-CooledUn-Cooled

This is the most common type of This is the most common type of thermal-imaging device. The thermal-imaging device. The infrared-detector elements are infrared-detector elements are contained in a unit that operates at contained in a unit that operates at room temperature. This type of room temperature. This type of system is completely quiet, activates system is completely quiet, activates immediately and has the battery immediately and has the battery built right in.built right in.

CooledCooled

More expensive and more susceptible to More expensive and more susceptible to damage from rugged use, these systems damage from rugged use, these systems have the elements sealed inside a container have the elements sealed inside a container that cools them to below 32 F (zero C). The that cools them to below 32 F (zero C). The advantage of such a system is the incredible advantage of such a system is the incredible resolution and sensitivity that result from resolution and sensitivity that result from cooling the elements. Cryogenically-cooled cooling the elements. Cryogenically-cooled systems can "see" a difference as small as systems can "see" a difference as small as 0.2 F (0.1 C) from more than 1,000 ft (300 0.2 F (0.1 C) from more than 1,000 ft (300 m) away, which is enough to tell if a person m) away, which is enough to tell if a person is holding a gun at that distance..is holding a gun at that distance..

Continue……Continue……

Unlike traditional most night-vision Unlike traditional most night-vision equipment which uses image-equipment which uses image-enhancement technology, thermal enhancement technology, thermal imaging is great for detecting people imaging is great for detecting people or working in near-absolute or working in near-absolute darkness with little or no ambient darkness with little or no ambient lighting (i.e. stars, moonlight, etc, ) lighting (i.e. stars, moonlight, etc, )

NIGHT VISION DEVICESNIGHT VISION DEVICES Night vision devices are basically divided Night vision devices are basically divided into three categories:into three categories:

Scopes: Scopes: They are monocular normally They are monocular normally handheld or mounted on a weapon.handheld or mounted on a weapon.

Goggles: Goggles: They are binocular and worn on They are binocular and worn on the head.the head.

Cameras: Cameras: Used for transmission or Used for transmission or recording of images mostly if the location recording of images mostly if the location is fixed.is fixed.

GENERATIONS:-GENERATIONS:-

Generation 1 : eg:-M1,M4

Generation 2 : eg:-AN/PVS-2

Generation 3 : eg:-AN/PVS-4 , SUPER GEN

Generation 4 : eg:-AN/PVS-7 , AN/PVS-14 NVS-7 ,NVS-14

GENERATION 1 GENERATION 1

The first night vision devices, the M1 and M3 The first night vision devices, the M1 and M3 infrared night sighting devices, also known as infrared night sighting devices, also known as the "sniperscope" or "snooperscope", were the "sniperscope" or "snooperscope", were introduced by the US Army in World War II, introduced by the US Army in World War II, and also used in the Korean War, to assist and also used in the Korean War, to assist snipers. They were active devices, using a snipers. They were active devices, using a large infrared light source to illuminate large infrared light source to illuminate targets. Their image intensifier tubes function targets. Their image intensifier tubes function using an anode and an S-1 photocathode, using an anode and an S-1 photocathode, made primarily of silver, caesium and oxygen made primarily of silver, caesium and oxygen to accelerate the electronsto accelerate the electrons

GENERATION 2GENERATION 2

Second generation passive devices, Second generation passive devices, introduced during the Vietnam War were an introduced during the Vietnam War were an adaptation of earlier active Gen 1 technology, adaptation of earlier active Gen 1 technology, and rely on ambient light instead of an and rely on ambient light instead of an infrared light source. Using an S-20 infrared light source. Using an S-20 photocathode, their image intensifiers photocathode, their image intensifiers produce a light amplification of around produce a light amplification of around 1000x, but are quite bulky and require 1000x, but are quite bulky and require moonlight to function properly.moonlight to function properly.

Examples:Examples: AN/PVS-2AN/PVS-2

GENERATION 3GENERATION 3 Third generation devices featured an improved Third generation devices featured an improved

image-intensifier tube utilizing micro-channel plate image-intensifier tube utilizing micro-channel plate (MCP)(MCP) with an S-25 photocathodewith an S-25 photocathode , resulting in a , resulting in a much brighter image, especially around edges of much brighter image, especially around edges of the lens. This leads to increased illumination in low the lens. This leads to increased illumination in low ambient light environments, such as moonless ambient light environments, such as moonless nights. Light amplification was around 20000x Also nights. Light amplification was around 20000x Also improved were image resolution and reliability.improved were image resolution and reliability.

Examples:Examples: AN/PVS-4AN/PVS-4 AN/PVS-5AN/PVS-5 SUPERGENSUPERGEN

GENERATION 4GENERATION 4 Fourth generation night vision systems maintain the Fourth generation night vision systems maintain the

MCP from Gen II, but now use a photocathode made MCP from Gen II, but now use a photocathode made with gallium arsenide, which further improves image with gallium arsenide, which further improves image resolution. In addition, the MCP is coated with an ion resolution. In addition, the MCP is coated with an ion barrier film for increased tube life. The light barrier film for increased tube life. The light amplification is also improved, to around 30000-amplification is also improved, to around 30000-50000x 50000x

Examples:Examples: AN/PVS-7AN/PVS-7 NVS-7NVS-7 AN/PVS-14AN/PVS-14 NVS-14NVS-14 XD-4, autogated or notXD-4, autogated or not

Continued……Continued……

GEN 2 GEN 3 % Improvement

Photoresponse(µA/Im)

1800 1800 -

Signal-to-Noise Ratio

21.0 25 20% Higher

Resolution(lp/mm)

64 64 -

Halo(mm) 1.25 0.75 40% Smaller

Reliability(hours)

10,000 10,000 -

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How Far Can We See ??How Far Can We See ?? There are many different variables that can effect the There are many different variables that can effect the

distance that we see with a Night Vision device.distance that we see with a Night Vision device. First which object we want to see.First which object we want to see. The larger the object the easier it is too see.The larger the object the easier it is too see. Second. Another variable is lighting conditions. The Second. Another variable is lighting conditions. The

more ambient light we have (starlight, moonlight, more ambient light we have (starlight, moonlight, infrared light) the better and further we will be able to infrared light) the better and further we will be able to see .If it is cloudy and overcast then we typically state see .If it is cloudy and overcast then we typically state that we can tell the difference between a male and a that we can tell the difference between a male and a female or a dog and a deer at about 75 to 100 yards.female or a dog and a deer at about 75 to 100 yards.

If there is ambient light then we can see about 500 If there is ambient light then we can see about 500 yards.yards.

BLACK SPOTS ON THE BLACK SPOTS ON THE SCREENSCREEN

As we look through a As we look through a night vision device we night vision device we may notice black spots may notice black spots on the screen. A NVD is on the screen. A NVD is similar to a television similar to a television screen and attracts dust screen and attracts dust and dirt. Typically these and dirt. Typically these spots can be cleaned.spots can be cleaned.

These black spots will These black spots will not affect the not affect the performance or performance or reliability of the night reliability of the night vision device.vision device.

APPLICATIONSAPPLICATIONS Military Military Hunting Hunting Wildlife observation Wildlife observation Surveillance Surveillance Security Security Hidden-object detection Hidden-object detection EntertainmentEntertainment

SECURITY SYSTEMSECURITY SYSTEM

MECHANICAL APPLICATIONMECHANICAL APPLICATION

BLAST FURNACE MONITORI NGBLAST FURNACE MONITORI NG

ConclusionConclusion Today in the 21Today in the 21stst century we have come a long century we have come a long

way in the development of night vision way in the development of night vision technology, from the early 1950’s. technology, from the early 1950’s.

Night vision devices are basically designed for Night vision devices are basically designed for utmost defensive purposes.utmost defensive purposes.

In present scenario the applications of night In present scenario the applications of night vision technology is very essential to combat vision technology is very essential to combat terrorism which is a major problem being faced terrorism which is a major problem being faced by mankind.by mankind.

ReferencesReferences

1.WWW.WIKIPEDIA.ORG1.WWW.WIKIPEDIA.ORG

2.EN.WIKIPEDIA.ORG/WIKI/NIGHT_VISION_DEVICE2.EN.WIKIPEDIA.ORG/WIKI/NIGHT_VISION_DEVICE

3.WWW.MOROVISION.COM/3.WWW.MOROVISION.COM/HOW_THERMAL_IMAGING_WORKS.HTMHOW_THERMAL_IMAGING_WORKS.HTM

4.EN.WIKIPEDIA.ORG/WIKI/NIGHT_VISION4.EN.WIKIPEDIA.ORG/WIKI/NIGHT_VISION

Questions??Questions??