11-01-2013, 03:48 PM
NIGHT VISION TECHNOLOGY
NIGHT VISION TECHNOLOGY.pptx (Size: 1.52 MB / Downloads: 62)
INTRODUCTION
Night vision is the ability to see in low light conditions.
Humans have poor night vision compared to many animals, in part because the human eye does not have a tapetum lucidum
The tapetum lucidum(Latin: "bright tapestry", plural tapeta lucida) 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.
INTERESTING FACTS ABOUT NIGHT VISION
With the proper NVD, you can see a person standing over 200 yards(183m) on a moonless, cloudy night.
The first Night vision devices (NVD) were created during World War II by placing an infrared filter over a searchlight.
Military uses it extensively, but it has public use also. E.g.: Hunting, Surveillance, Navigation etc.
Night vision are known for there eerie green tint.
NIGHT VISION TECHNOLOGY
The major night vision technology used are:
Image Enhancement: This captures the lower portion of infra red light and amplifies it for the human eyes. These are also called Night Vision Devices.
Thermal Imaging: It captures the upper portion of infra red spectrum emitted as heat by the objects.
FEATURES OF NIGHT VISION TECHNOLOGY
Automatic brightness control : An electronic feature that automatically reduces voltage to the micro channel plate to keep the image intensifier’s brightness within optimal limits and protect the tube.
Automated power supply : By this we mean that the signal is turning itself ON and OFF at a very rapid rate This combined with a thin film attached to the micro channel plate reduces blooming.
Black spots : They do not affect the performance of NVD and are inherent in the manufacturing process.
APPLICATIONS
Common applications for night vision include:
Military
Law enforcement
Hunting
Wildlife observation
Surveillance
Security
Navigation
Hidden-object detection
Entertainment