29-10-2010, 12:36 AM
Night Vision Technology
Sarath S Panicker
College Of Engineering, Kalloopara
2007-11 batch
[attachment=6965]
Introduction
Literally allows one to see in the dark.
With the proper night-vision equipment, you can see a person standing over 200 yards away on a moonless, cloudy night.
Originally developed for military use.
Federal and state agencies now routinely utilize the technology for site security, surveillance as well as search and rescue.
Various Night Vision Snaps
Night Vision Technology
Night Vision can work in two different ways depending on the technology used.
1.Image enhancement
2:Thermal imaging
Image enhancement
Image Enhancement
Collects the tiny amounts of light including the lower portion of the infrared light spectrum.
&
Amplify it to the point that we can easily observe the image.
How Image Enhancement works?
Objective lens captures ambient light and some near-infrared light.
The gathered light is sent to the image-intensifier tube.
The tube outputs a high voltage to the image-tube components.
The image-intensifier tube has a photocathode, which is used to convert the photons of light energy into electrons.
As the electrons pass through the tube, similar electrons are released from atoms in the tube, multiplying the original number of electrons using a microchannel plate (MCP) in the tube.
At the end of the image-intensifier tube, the electrons hit a screen coated with phosphors.
The energy of the electrons causes the phosphors to reach an excited state and release photons.
The green phosphor image is viewed through the ocular lens, which allows you to magnify and focus the image.
Thermal Imaging
Captures the upper portion of the infrared light spectrum, which is emitted as heat by objects.
Hotter objects, such as warm bodies, emit more of this light than cooler objects like trees or buildings.
How Thermal Imaging Works?
A special lens focuses the IR emitted by all of the objects in view.
The focused light is scanned by a phased array of infrared-detector elements.
The detector elements create a very detailed temperature pattern called a thermogram.
The thermogram is translated into electric impulses
The impulses are sent to a signal-processing unit, that translates the information from the elements into data for the display.
The signal-processing unit sends the information to the display, where it appears as various colors depending on the intensity of the IR emission.
Thermal Imaging Devices
Two Types:
Un-cooled : Contained in a unit that operates at room temperature.
Completely quiet.
Activates immediately.
In-built battery.
Cryogenically cooled : Elements sealed inside a container that cools them to below zero C.
Incredible resolution.
High Sensitivity.
Night Vision Products
GENERATION 1 (Developed in 1960's)
Vacuum Tube Technology
Full Moon Operation
Amplification: 1,000
Operating Life: 2,000 Hours
GENERATION 2 (Developed in 1970's)
First Micro channel Plate (MCP) Application
One-Quarter Moon Operation
Amplification: 20,000
Operating Life: 2,500 Hours
GENERATION 2+ (1970s)
Development increased image tube bias voltage to improve gain.
Additionally, a glass faceplate was added to improve resolution.
GENERATION 3 (Developed in 1990's)
Improved MCP & Photocathode
Starlight Operation
Amplification: 40,000
Operating Life: 10,000 Hour
GENERATION 4 Enhanced (2000's)
Improvements in the photocathode and MCP resulted in increased gain and resolution.
An improvement over GEN 2 & 3
Night Vision Equipments
Characteristics of Night Vision
Some of the aspects of night vision that you should be aware of when you are using an image intensified night vision system.
Textures, Light and Dark
Depth Perception
Fog and Rain
Honeycomb
Black Spots
Applications
Military
Law enforcement
Hunting
Wildlife observation
Surveillance
Security
Navigation
Hidden-object detection
Advantages
High sensitivity in low-light
High speed imaging capability
Able to detect people and vehicles at at great distances
Eliminates shadows and reveal identifying lettering numbers and Objects
Disadvantages
Near illumination is required
U can get blind if u look at something bright
Blooming- night vision images gets partilaaly distorted or completely distored.
Optical distortion-classic&manufacturing
Night vision technology in cars
Conclusion
Night vision technology was developed by the US defense department mainly for defense purposes
Night Vision Technologies are now used in the daily lives.
While thermal imaging is great for detecting people or working in near-absolute darkness, most night-vision equipment uses image-enhancement technology.
Many people are beginning to discover the unique world that can be found after darkness falls
One estimate shows an entire battalion could be outfitted with the ability to "own the night" for less than two million dollars
In future many Other method will used for efficient way of working of Night Vision Technology
Future Scope
The United States Air Force is experimenting with Panoramic Night Vision Goggles (PNVGs) which double the user's field of view to around 95 degrees by using four 16 mm image intensifiers tubes, rather than the more standard two 18 mm tubes.And lets hope that more and more advancements will be made in the field of night vision technologies so that we can also “own the night” one day…………
References
1. answer.com
2. nightvision.com
3. google.com
4. wikipedia.org
[attachment=6965]
Sarath S Panicker
College Of Engineering, Kalloopara
2007-11 batch
[attachment=6965]
Introduction
Literally allows one to see in the dark.
With the proper night-vision equipment, you can see a person standing over 200 yards away on a moonless, cloudy night.
Originally developed for military use.
Federal and state agencies now routinely utilize the technology for site security, surveillance as well as search and rescue.
Various Night Vision Snaps
Night Vision Technology
Night Vision can work in two different ways depending on the technology used.
1.Image enhancement
2:Thermal imaging
Image enhancement
Image Enhancement
Collects the tiny amounts of light including the lower portion of the infrared light spectrum.
&
Amplify it to the point that we can easily observe the image.
How Image Enhancement works?
Objective lens captures ambient light and some near-infrared light.
The gathered light is sent to the image-intensifier tube.
The tube outputs a high voltage to the image-tube components.
The image-intensifier tube has a photocathode, which is used to convert the photons of light energy into electrons.
As the electrons pass through the tube, similar electrons are released from atoms in the tube, multiplying the original number of electrons using a microchannel plate (MCP) in the tube.
At the end of the image-intensifier tube, the electrons hit a screen coated with phosphors.
The energy of the electrons causes the phosphors to reach an excited state and release photons.
The green phosphor image is viewed through the ocular lens, which allows you to magnify and focus the image.
Thermal Imaging
Captures the upper portion of the infrared light spectrum, which is emitted as heat by objects.
Hotter objects, such as warm bodies, emit more of this light than cooler objects like trees or buildings.
How Thermal Imaging Works?
A special lens focuses the IR emitted by all of the objects in view.
The focused light is scanned by a phased array of infrared-detector elements.
The detector elements create a very detailed temperature pattern called a thermogram.
The thermogram is translated into electric impulses
The impulses are sent to a signal-processing unit, that translates the information from the elements into data for the display.
The signal-processing unit sends the information to the display, where it appears as various colors depending on the intensity of the IR emission.
Thermal Imaging Devices
Two Types:
Un-cooled : Contained in a unit that operates at room temperature.
Completely quiet.
Activates immediately.
In-built battery.
Cryogenically cooled : Elements sealed inside a container that cools them to below zero C.
Incredible resolution.
High Sensitivity.
Night Vision Products
GENERATION 1 (Developed in 1960's)
Vacuum Tube Technology
Full Moon Operation
Amplification: 1,000
Operating Life: 2,000 Hours
GENERATION 2 (Developed in 1970's)
First Micro channel Plate (MCP) Application
One-Quarter Moon Operation
Amplification: 20,000
Operating Life: 2,500 Hours
GENERATION 2+ (1970s)
Development increased image tube bias voltage to improve gain.
Additionally, a glass faceplate was added to improve resolution.
GENERATION 3 (Developed in 1990's)
Improved MCP & Photocathode
Starlight Operation
Amplification: 40,000
Operating Life: 10,000 Hour
GENERATION 4 Enhanced (2000's)
Improvements in the photocathode and MCP resulted in increased gain and resolution.
An improvement over GEN 2 & 3
Night Vision Equipments
Characteristics of Night Vision
Some of the aspects of night vision that you should be aware of when you are using an image intensified night vision system.
Textures, Light and Dark
Depth Perception
Fog and Rain
Honeycomb
Black Spots
Applications
Military
Law enforcement
Hunting
Wildlife observation
Surveillance
Security
Navigation
Hidden-object detection
Advantages
High sensitivity in low-light
High speed imaging capability
Able to detect people and vehicles at at great distances
Eliminates shadows and reveal identifying lettering numbers and Objects
Disadvantages
Near illumination is required
U can get blind if u look at something bright
Blooming- night vision images gets partilaaly distorted or completely distored.
Optical distortion-classic&manufacturing
Night vision technology in cars
Conclusion
Night vision technology was developed by the US defense department mainly for defense purposes
Night Vision Technologies are now used in the daily lives.
While thermal imaging is great for detecting people or working in near-absolute darkness, most night-vision equipment uses image-enhancement technology.
Many people are beginning to discover the unique world that can be found after darkness falls
One estimate shows an entire battalion could be outfitted with the ability to "own the night" for less than two million dollars
In future many Other method will used for efficient way of working of Night Vision Technology
Future Scope
The United States Air Force is experimenting with Panoramic Night Vision Goggles (PNVGs) which double the user's field of view to around 95 degrees by using four 16 mm image intensifiers tubes, rather than the more standard two 18 mm tubes.And lets hope that more and more advancements will be made in the field of night vision technologies so that we can also “own the night” one day…………
References
1. answer.com
2. nightvision.com
3. google.com
4. wikipedia.org
[attachment=6965]
