Unlike most other jobs, military and law enforcement personnel have to perform their duties around the clock. This means that they may face threatening situations at any given time. When carrying out combat during the night, night vision goggles are one of the most important pieces of equipment one can carry.
Originally used for the first time during the 2nd World War, their mass scale usage started during the Vietnam War. Since then, night vision goggles have come a long way and have become more and more sophisticated.
The early night vision devices
The earlier night vision devices, or NVDs were meant to be used for tanks and planes carrying out mission during the night time. Some very also designed for use by snipers. These NVDs were relatively less sophisticated and relied on the availability of light from natural sources such as moon during night time.
Initially S-20 photocathodes were used in Gen I night vision devices, followed by S-25 photocathodes in Gen II which offered better results. Eventually, Gen III night vision devices had photocathodes made of gallium arsenide which allowed better photo resolution.
Types of night vision goggles
Initially, there only one type of night vision goggles that primarily concentrated on image enhancement. However, thermal imaging night vision goggles have also been in used for a fair amount of time and they perform an amazing job. Let’s learn more about the two types.
Image Intensifier Goggles
These work by amplifying small amounts of light including those at the lower portion of the infrared spectrum. Some of these lights are imperceptible to the naked eye. They use the photocathodes to convert the photon into electrons which are further enhanced using high voltage into a microchannel plate. They then go through a screen with phosphorous and create a near perfect image. These goggles, though highly accurate, have certain limitations in adverse conditions such as visibility in fog or when there is a high light reflection from other objects.
Thermal Imaging Goggles
Thermal imaging works by capturing the upper spectrum of infrared light. It works by creating imagery based on the heat emitted by the different objects. Human bodies typically release greater amount of heat when compared with different structures or plantation and thus are clearly visible in thermal imaging goggles. They have an added advantage of showing anyone hiding in camouflage or behind a smokescreen due to the nature of its functionality.
Other benefits of night vision devices
These devices also are used for aviation, climbing expeditions and wildlife observations. Civilian usage laws for night vision goggles are dictated by the authorities in different countries and permitted uses may vary around the world.