Final Ppt Of Night Vision 306h4a

NIGHT VISION TECHNOLOGY THE BULLETS DON’T CARE HOW DARK IT IS

BY

Pradeep.S 4MH08EC026

OUTLINE INTRODUCTION THE BASICS OF INFRARED NIGHT VISION THERMAL IMAGING IMAGE ENHANCEMENT GENERATIONS EQUIPMENT AND APPLICATIONS CONCLUSION REFERENCES

INTRODUCTION 

What is Night Vision Technology ?

"Night Vision" as referenced here is that technology that provides us with the miracle of vision in total

darkness and the improvement of vision in low light environments. It is invented by the U.S.Army.

Infrared light is used in this technology.

Humans have poor night vision compared to many animals, in part because the human eye does not have a tapetum lucidum The tapetum lucidum is a layer of tissue in the eye of many animals, that lies immediately behind or sometimes within the retina. It reflects visible light back through the retina, increasing the light available to the photoreceptors. This improves vision in low-light conditions.

THE BASICS OF INFRARED 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 light can be split into three categories Near-infrared (near-IR) - Closest to visible light, near-IR has wavelengths that range from 0.7 to 1.3 microns meter. Mid-infrared (mid-IR) - Mid-IR has wavelengths ranging from 1.3 to 3 microns. Both near-IR and mid-IR are used by a variety of electronic devices, including remote controls

Thermal-infrared (thermal-IR) - Occupying the largest part of the infrared spectrum, thermal-IR has wavelengths ranging from 3 microns to over 30 microns

WORKING OF NIGHT VISION DEVICES – Night Vision technology consists of two major types: – image intensification (light amplification) and – Thermal imaging(infrared).

Thermal Imaging / Thermography Different from low-light imaging methods of night vision (which require some ambient light in order to produce an image), thermal imaging night vision methods do not require any ambient light at all. They operate on the principal that

all objects emit infrared energy as a function of their temperature. In general, the hotter an object is, the more radiation it emits. A thermal imager is a product that collects the infrared radiation from objects in the scene and creates an electronic

image Thermal images are normally black and white in nature, where black objects are cold and white objects are hot. Some thermal cameras show images in color.

► Capturing

infrared light

emitted by objects to form images ► The

cooler the object, the less

clear the image will be ► Good

nights

for moonless, cloudy

TYPES OF THERMAL IMAGING DEVICES  

 

Un-cooled Infrared Detector: The infrared-detector elements are contained in a unit that operates at room temperature. Bulky in size. Higher reliability than cooled detector thermal imagers .

Cooled Infrared Detector:  Expensive and susceptible to damage.  infrared-detector elements are sealed inside a container that cools them to below 32 F .  Able to detect people and vehicles at great distances.  Not affected by bright light sources 

IMAGE INTENSIFICATION

 It is also called light amplification  It is less expensive than thermal  Light amplification technology takes the small amount of light, such as moonlight or starlight, that is in the surrounding area, and converts the light energy (scientists call it photons), into electrical energy (electrons)

Disadvantages

Advantages

   

 Possibility of blooming and damage when observing bright sources under low-light conditions Excellent low-light level sensitivity.  Because they are based on amplification High resolution. methods, some light is required. This Low power and cost. method is not useful when there is Ability to identify people. essentially no light.



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

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

THE IMAGE IS GREEN BECAUSE THE PHOSPHOR IS GREEN IN COLOR THAT IS GOOD FOR HUMAN EYE TO PICK UP DETAIL

Generation-0

Created by US Army  Uses active infrared  A projection unit called IR illuminator is attached  Full moon operation

Generation-1 (1960’s) Uses ive infrared Uses ambient light provided by the moon and the stars Don’t require a source of projected infrared light Don’t work well on cloudy or moonless nights One quarter moon operation

Generation-2 (1970’s) Able to see in extreme low light conditions due to the addition of micro

Generation-3 (1990’s) Better resolution and sensitivity Photocathode is made up of Gallium

channel plate(M) to the imageintensifier tube The images are less distorted and

brighter

Arsenide M is coated with an ion barrier Tube life is increased

Generation-4 (2000’s) Shows significant improvement in both high- and low-level light environments

No ion barrier in M Responds quickly to different lightning conditions Reduced background noise Images are less distorted and brighter 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

HOW FAR CAN WE SEE ?? There are many different variables that can effect the distance that we see with a Night Vision device.  First which object we want to see. The larger the object the easier it is too see.  Second. Another variable is lighting conditions. The more ambient light we have (starlight, moonlight, infrared light) the better and further we will be able to see . If it is cloudy and overcast then we typically state that we can tell the difference between a male and a female or a dog and a deer at about 75 to 100 yards.

Characteristics of Night Vision

Textures, Light and Dark Depth Perception Honey comb Fog and Rain This is a faint hexagonal Honeycomb pattern which is the result of the Spots manufacturing process.

Textures, light and dark

The objects that are clearly visible on day appear dark and vice versa through night vision unit.  Fog and Rain Fog and rain reflect more light towards the night vision unit and this may degrade its performance.

BLACK SPOTS ON THE SCREEN

Comparison Half moon 0.05lux (meters)

Quartermoon 0.01lux ( meters)

Starlight 0.001lux ( meters)

230

130

45

_________

________

Generation I

300

200

150

100

50

Generation II

630

630

590

390

145

Generation III

810

810

770

530

200

International Identification range (human)

Without nightvision device

Full moon 0.1lux ( meters)

Overcast 0.0001lux ( meters)

NIGHT VISION DEVICES

• GOGGLES - While goggles can be handheld, they are most often worn on the head. Goggles are binocular (two eye-pieces) and may have a single lens or stereo lens, depending on the model. •

DARK INVADER Night-vision Goggles 4501

Goggles are excellent for constant viewing, such as moving around in a dark building.

• CAMERAS - Cameras with night-vision technology can send the image to a monitor for display.

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

• When night-vision capability is desired in a permanent location, such as on a building or as part of the equipment in a helicopter, cameras are used. • Also used for Wildlife photography and movie making.

Dark Invader Multipurpose Pocket-Scope

A Soldier equipped with Night Vision Binocular

A Night Vision Long Ranged Binocular

MISSION Night Vision’s mission is to: Acquire and Target enemy force in battlefield environment. Deny enemy surveillance & acquisition through electro-optic. For night driving and autopilot.

COMMON APPLICATIONS: Military Hunting Wildlife observation Surveillance Security Navigation Hidden-object detection Entertainment

Law Enforcement

Military

Nature

Miscellaneous

Night Vision System in Cars

 Night Vision makes a vehicle’s darkened surrounding visible out

to a distance of 150 meters.  Night Vision generates an electronically processed video image that can be displayed in real time in the head-up display.

Conclusion It’s a critical study, which plays a vital role in modern world as it is involved with advance use of science and technology.

The advances in technology have created the tremendous opportunities for Vision System and Image Processing. The technology has evolved greatly since their introduction, leading to several “generation” of night vision equipment with performance increasing and price decreasing.

From the above discussion we can conclude that this field has relatively more advantages and disadvantages and hence is very useful in varied branches.

References  [1] IEEE TRANSACTIONS ON INTELLIGENT TRANSPORTATION SYSTEMS, VOL. 3, NO. 3, SEPTEMBER 2002, Development of Night-Vision System Takayuki Tsuji, Hiroshi Hattori, Masahito Watanabe, and Nobuharu Nagaoka  http://electronics.howstuffworks.com/nightvision3.ht ml  http://www.nightvision.com/military/militaryhome.h tml  http://www.morovision.com/hownightvisionworks.ht m