Night Vision Tech Ppt Rajesh Sharma
-
Upload
chandra-mohan -
Category
Documents
-
view
222 -
download
1
Transcript of Night Vision Tech Ppt Rajesh Sharma
-
7/31/2019 Night Vision Tech Ppt Rajesh Sharma
1/22
NIGHT VISION
TECHNOLOGY
-
7/31/2019 Night Vision Tech Ppt Rajesh Sharma
2/22
NIGHT VISION TECHNOLOGY
IntroductionTypes of NVT
Thermal Imaging
Image EnhancementEquipments
Applications
ConclusionReferences
-
7/31/2019 Night Vision Tech Ppt Rajesh Sharma
3/22
Introduction
NVT allows us to see in the dark
Originally developed for military use
Now used for site security, surveillance
as well as search and rescueNight vision devices can work in two
different ways,depending on thetechnology used:
Thermal imaging
Image enhancement.
-
7/31/2019 Night Vision Tech Ppt Rajesh Sharma
4/22
Types of night vision
Categorized by generations
Each substantial change NVTestablishes a new generation
Categorized into:Generation-0
Generation-1
Generation-2Generation-3
Generation-4
-
7/31/2019 Night Vision Tech Ppt Rajesh Sharma
5/22
Generation-0
Created by US Army Uses active infrared A projection unit called IR illuminator
is attached
Full moon operation Use anode in conjunction with cathode
to accelerate the electrons Problemsacceleration causes
distortion of image as well asreduction of life of the tube Also, it was quickly duplicated by the
hostile nations
-
7/31/2019 Night Vision Tech Ppt Rajesh Sharma
6/22
Generation-1 (1960s)
Uses passive infrared
Uses ambient light provided by the moonand the stars
Dont require a source of projectedinfrared light
Dont work well on cloudy or moonlessnights
Uses same image-intensifier tubetechnology as Generation-0
Same problems as faced by theGeneration-0
-
7/31/2019 Night Vision Tech Ppt Rajesh Sharma
7/22
Generation-2 (1970s)
Offer improved resolution andperformance over Generation-1 devices
Considerably more reliable
Able to see in extreme low lightconditions due to the addition ofmicrochannel plate(MCP) to the image-intensifier tube
The images are less distorted andbrighter
-
7/31/2019 Night Vision Tech Ppt Rajesh Sharma
8/22
Generation-3 (1990s)
Currently used by the US Army
Better resolution and sensitivity
Photocathode is made up of Gallium
ArsenideMCP is coated with an ion barrier
Tube life is increased
-
7/31/2019 Night Vision Tech Ppt Rajesh Sharma
9/22
Generation-4 (2000s)
Known as filmless and gatedtechnology
Shows significant improvement in bothhigh- and low-level light environments
No ion barrier in MCP
Responds quickly to different lightningconditions
Reduced background noiseEnhances signal to noise ratio
Images are less distorted and brighter
-
7/31/2019 Night Vision Tech Ppt Rajesh Sharma
10/22
Thermal imagingThis technology operates by capturing
upper portion of the infrared lightspectrum, which is emitted as heat
Hotter objects emit more of this lightthan the cooler objects
These elements then create athermogram
Thermogram electric pulses display
data
-
7/31/2019 Night Vision Tech Ppt Rajesh Sharma
11/22
The basic components of aThermal-imaging system
-
7/31/2019 Night Vision Tech Ppt Rajesh Sharma
12/22
Thermal imaging
Thermal imaging lets you see again.
It is quite easy to see everythingduring the day...
...but at night, you can seevery little.
-
7/31/2019 Night Vision Tech Ppt Rajesh Sharma
13/22
Thermal imaging devices
Two types:
1. Uncooled.
2. Cryogenically cooled.
Great for detecting people or
working in near-absolutedarkness
-
7/31/2019 Night Vision Tech Ppt Rajesh Sharma
14/22
Image Enhancement
It is also known as Image intensificationRelies on image intensifier tube to collect
an amplify infrared and visible light Lens captures the light which is then sent
to image intensifier tube It has photocathode that converts photons
into electronsWhen electrons pass through MCP ,more
electrons are presented
This causes chain reaction where atomsare released
Electrons reach phosphor screen andphotons are released
Those phosphor create green image
-
7/31/2019 Night Vision Tech Ppt Rajesh Sharma
15/22
Image Enhancement
-
7/31/2019 Night Vision Tech Ppt Rajesh Sharma
16/22
Equipments
Three categories
Scopes
Goggles
Cameras
-
7/31/2019 Night Vision Tech Ppt Rajesh Sharma
17/22
DARK INVADER Multi-purpose Pocketscope
DARK INVADER Night-vision Goggles 4501
-
7/31/2019 Night Vision Tech Ppt Rajesh Sharma
18/22
Stealth 301 Series Day/Night Video Camera
Camcorders are a fast-growing segment of the night-vision industry.
-
7/31/2019 Night Vision Tech Ppt Rajesh Sharma
19/22
MilitaryLaw enforcement
Hunting
Wild life observation
Surveillance
Security
Navigation
Hidden-object detection
Applications
-
7/31/2019 Night Vision Tech Ppt Rajesh Sharma
20/22
Conclusions
Although the term ``night vision''currently encompasses threedistinct technologies, it is the
evolution of image intensificationtechnology that first made devicespractical and widely used.
Their success was the result ofadvancements in light amplificationand resolution techniques.
-
7/31/2019 Night Vision Tech Ppt Rajesh Sharma
21/22
References
http://electronics.howstuffworks.com/nightvision3.html http://www.nightvision.com/military/militaryhome.html http://www.physics.ohio-
state.edu/~wilkins/writing/Samples/shortmed/johnmedium/index.html
http://www.atncorp.com/HowNightVisionWorks http://www.morovision.com/hownightvisionworks.htm http://www.alanaecology.com/acatalog/Introduction_to_
Nightvision.html
-
7/31/2019 Night Vision Tech Ppt Rajesh Sharma
22/22