night vision technology

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NIGHT VISION TECHNOLOHY

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NIGHT VISION TECHNOLOGY : 

NIGHT VISION TECHNOLOGY PRESENTED BY- FARHA ZEBA BRANCH - (E.C. -1) ROLL NO.- 1045031031

INTRODUCTION : 

INTRODUCTION Night vision technology allows one to see in the dark. It is originally developed for the military use. With the proper night vision equipment we can see a person standing over 200 yards away on a moonless cloudy night.

During the day... At night.. With night vision device

CHARACTERISTICS OF NIGHT VISION : 

CHARACTERISTICS OF NIGHT VISION TEXTURES, LIGHT AND DARK- Objects that appear light during the day may appear darker through the night vision device. DEPTH PERCEPTION- Night vision does not present normal depth perception. FOG AND RAIN- Due to fog and heavy rain its performance is degraded. BLACK SPOTS- These spots remain constant and should not increase in size or number.

Night vision approaches : 

Night vision approaches There are two types of night vision approaches – 1) Spectral range- Enhanced spectral range allows the viewer to take advantage of non-visible sources of electromagnetic radiation (such as near-infrared or ultraviolet radiation). Some animals can see well into the infrared or ultraviolet compared to humans. 2)Intensity range: It is the ability to see with very small quantities of light.Many animals have better night vision than humans do, enhanced intensity range is achieved via technological means through the use of an image intensifier, gain multiplication devices and photo detectors.

Types of night vision : 

Types of night vision Depending upon the way it is implemented it is broadly classified into two types- 1)Biological night vision: Molecules in the rods of the eye undergo a change in shape as light. Rhodopsin are sensitive to light and gets depleted and take 30 min. to regenerate .  Rhodopsin in the human rods is less sensitive to the longer red wavelengths of light. 2) Technical night vision: Night vision technologies can be broadly divided into two main categories: Image intensification Thermal imaging

Working of technical night vision : 

Working of technical night vision Night vision can work in two very different ways , depending on the technology used : 1)IMAGE INTENSIFICATION This method of night vision amplifies the available light to achieve better vision. A conventional lens, captures ambient light. The light energy causes electrons to be released from the photocathode plate.

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These electrons enter a micro channel plate and generate more electrons These electrons hit a phosphor screen and maintain their position through the channel. These phosphors create green image on the screen which is viewed through another lens, called the ocular lens.

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2) THERMAL IMAGING This method do not require any ambient light at all. principal -: All objects emit infrared energy as a function of their temperature. This technology operates by capturing the upper portion of infra red light spectrum. A special lens focuses the infrared light emitted by all of the objects in view. The focused light is scanned and create temperature pattern called THERMOGRAM. The pattern created is translated into electric impulses .

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The impulses are sent to a circuit board that translates the information into data for the display. signal-processing unit sends the information to the display.

GENERATIONS : 

GENERATIONS GENERATION 0 Night vision devices were based on image conversion rather than on image intensification. The first night vision device the "sniperscope" or "snooperscope", were introduced by the US Army in World War II GENERATION 1 Focused on the ability to see without additional light. NVD began using intensified natural lighting. Military scientists created two – stage cascade image tube.

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GENERATION 2 There were two major development in NVD technology , first was the micro channel plate and other was in thermal imaging. The images are less distorted and brighter GENERATION 3 Longer life and more defined images. It maintains the MCP from GEN 2 and also it has photocathode plate. Better resolution and sensitivity. GENERATION 4 Known as “filmless and gated” technology. improvement in high- and low-level light environments Reduced background noise

NIGHT VISION DEVICES : 

NIGHT VISION DEVICES Night vision devices are basically divided into three categories Scopes: They are monocular normally handheld or mounted on a weapon. Goggles: They are binocular and worn on the head. Cameras: Used for transmission or recording of images mostly if the location is fixed.

APPLICATIONS : 

APPLICATIONS Military Law enforcement Hunting and wildlife observation Security Navigation Entertainment

CONCLUSION : 

CONCLUSION Development of night vision technology, from the early 1940’s The application within the scientific or the civilian range is often prohibited by law. It is essential to combat terrorism which is a major problem being faced by mankind. .

Thank you : 

Thank you

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