Being able to see is a crucial aspect of
safety and performance for soldiers, and as a result, various pieces of
tactical gear are equipped with night vision. Called night vision
devices, or NVDs, such tactical gear encompasses goggles, binoculars,
illuminators, and sights designed for warfighters or law enforcement
professionals. NVDs are used by soldiers for surveillance, navigation,
vehicle operations, exact shooting, and stealthily approaching targets
and increase operational capabilities.
Tactical gear with night vision capabilities falls into one of two types: light amplification and thermal enhancement. The former, also known as image enhancement, is more common. On a basic level, a light amplification NVD has an Image Intensifier Tube that collects and amplifies infrared and invisible light. To do this, the tube converts photons into electrons and then converts them back again.
Thermal imaging, or enhancement, takes advantage of the fact that all objects emit infrared energy, which is proportional to the amount of heat it produces. NVDs with thermal enhancement sense infrared energy and then provide a thermal image of an area. Thermal imaging devices are either un-cooled or cryogenically cooled, with the former being more common. Cryogenically cooled thermal imaging tactical gear, on the other hand, has a far higher degree of resolution and sensitivity, allowing the user to see a difference of 0.2°F of infrared energy from 1,000 feet away. Although both types of NVDs are effective in tactical environments, thermal imaging allows for detection of people and vehicles in near darkness with no ambient lighting and can also be used in full daylight.
Tactical gear with night vision capabilities has been in use for more than 40 years, and since its introduction by the U.S. Army during World War II, it has experienced several changes and improvements. The first night vision devices, called "Generation 0," used active infrared technology. An IR illuminator was attached to an NVD, and for an object to be visible, a beam of light had to reflect off it and bounce back to the lens of the NVD. On a scientific level, an anode was used with a cathode to accelerate electrons, but the process resulted in distorted images and was quickly duplicated by other nations.
Generation 1 NVDs were passive infrared. For an object to be seen, ambient light from the moon or stars compounded to normal amounts of reflected infrared light in an environment, but such an approach meant that the device did not work well in cloudy or moonless conditions. While Generation 1 used the same image-intensifier tube as Generation 0, the newer NVDs did not need a source of projected infrared light.
Generation 2 had significant improvements over the first two systems, especially to the image-intensifier tubes. With better resolution, performance, and reliability, Generation 2 NVDs could be used in low-light conditions. A microchannel plate (MCP) was also added to the image-intensifier tube. Rather than accelerating existing electronics, the MCP increased the number of them, resulting in less image distortion.
Currently in use by the U.S. Military, Generation 3 NVDs employ the same technology as the previous system but have better resolution and sensitivity capabilities. Specific changes include a photo cathode made with gallium arsenide, which efficiently converts photons to electronics. The MCP, as well, is coated with an ion barrier, which extends the lifespan of the tube.
Using "filmless and gated" technology, Generation 4 NVDs offer better vision in low- and high-level light environments. With the ion barrier on the MCP removed, the device reduces background noise and enhances the signal-to-noise ratio. More electrons can reach the amplification stage, which creates brighter images with less distortion. Generation 4 NVDs also use an automated gated power supply system, which allows the photocathode voltage to quickly switch on and off. The tactical gear, as a result, responds to rapidly fluctuating light conditions, and the user can move from high- to low-light areas without visual interference.
Tactical gear with night vision capabilities falls into one of two types: light amplification and thermal enhancement. The former, also known as image enhancement, is more common. On a basic level, a light amplification NVD has an Image Intensifier Tube that collects and amplifies infrared and invisible light. To do this, the tube converts photons into electrons and then converts them back again.
Thermal imaging, or enhancement, takes advantage of the fact that all objects emit infrared energy, which is proportional to the amount of heat it produces. NVDs with thermal enhancement sense infrared energy and then provide a thermal image of an area. Thermal imaging devices are either un-cooled or cryogenically cooled, with the former being more common. Cryogenically cooled thermal imaging tactical gear, on the other hand, has a far higher degree of resolution and sensitivity, allowing the user to see a difference of 0.2°F of infrared energy from 1,000 feet away. Although both types of NVDs are effective in tactical environments, thermal imaging allows for detection of people and vehicles in near darkness with no ambient lighting and can also be used in full daylight.
Tactical gear with night vision capabilities has been in use for more than 40 years, and since its introduction by the U.S. Army during World War II, it has experienced several changes and improvements. The first night vision devices, called "Generation 0," used active infrared technology. An IR illuminator was attached to an NVD, and for an object to be visible, a beam of light had to reflect off it and bounce back to the lens of the NVD. On a scientific level, an anode was used with a cathode to accelerate electrons, but the process resulted in distorted images and was quickly duplicated by other nations.
Generation 1 NVDs were passive infrared. For an object to be seen, ambient light from the moon or stars compounded to normal amounts of reflected infrared light in an environment, but such an approach meant that the device did not work well in cloudy or moonless conditions. While Generation 1 used the same image-intensifier tube as Generation 0, the newer NVDs did not need a source of projected infrared light.
Generation 2 had significant improvements over the first two systems, especially to the image-intensifier tubes. With better resolution, performance, and reliability, Generation 2 NVDs could be used in low-light conditions. A microchannel plate (MCP) was also added to the image-intensifier tube. Rather than accelerating existing electronics, the MCP increased the number of them, resulting in less image distortion.
Currently in use by the U.S. Military, Generation 3 NVDs employ the same technology as the previous system but have better resolution and sensitivity capabilities. Specific changes include a photo cathode made with gallium arsenide, which efficiently converts photons to electronics. The MCP, as well, is coated with an ion barrier, which extends the lifespan of the tube.
Using "filmless and gated" technology, Generation 4 NVDs offer better vision in low- and high-level light environments. With the ion barrier on the MCP removed, the device reduces background noise and enhances the signal-to-noise ratio. More electrons can reach the amplification stage, which creates brighter images with less distortion. Generation 4 NVDs also use an automated gated power supply system, which allows the photocathode voltage to quickly switch on and off. The tactical gear, as a result, responds to rapidly fluctuating light conditions, and the user can move from high- to low-light areas without visual interference.
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