Night vision devices

A night vision device (NVD), also known as a night optical/observation device (NOD), is an optoelectronic device that allows images to be produced in levels of light approaching total darkness. The image may be a conversion to visible light of both visible light and near-infrared, while by convention detection of thermal infrared is denoted thermal imaging. The image produced is typically monochrome, e.g. shades of green. NVDs are most often used by the military and law enforcement agencies, but are available to civilian users. The term usually refers to a complete unit, including an image intensifier tube, a protective and generally water-resistant housing, and some type of mounting system. Many NVDs also include optical components such as a sacrificial lens, or telescopic lenses or mirrors. An NVD may have an IR illuminator, making it an active as opposed to passive night vision device.

Night vision devices were first used in World War II and came into wide use during the Vietnam War. The technology has evolved greatly since their introduction, leading to several "generations" of night vision equipment with performance increasing and price decreasing. Consequently, they are available for a wide range of applications, e.g. for gunners, drivers and aviators.

The classification below was initially introduced by the US manufacturers through the US government. Other manufacturers do not abide by it.

In 1929, Hungarian physicist Kálmán Tihanyi invented the infrared-sensitive (night vision) electronic television camera for anti-aircraft defense in the UK.

The first military night vision devices were introduced by the German army as early as 1939. The first devices were being developed by AEG starting in 1935. In mid-1943, first tests with infrared night-vision (Nacht Jager) devices and telescopic rangefinders mounted on Panther started. Two different arrangements / solutions were created and used on Panther tanks. Solution A - Sperber FG 1250 (Sparrow Hawk), with range up to 600m, was made up of one 30 cm infrared searchlight and image converter operated by the commander. This was matched by an earlier experimental Russian version dubbed the PAU-2 and was field tested in 1942. From late 1944 to March 1945, some Panzerkampfwagen V Panther Ausf G (and other variants) mounted with FG 1250, were successfully tested. By the end of World War II, the German Reich had equipped approximately 50 (or 63) Panther tanks, which saw combat on both the Eastern and Western Fronts. The "Vampir" man-portable system for infantrymen was being used with Sturmgewehr 44 assault rifles. Parallel development of night vision systems occurred in the US. The M1 and M3 infrared night sighting devices, also known as the "sniperscope" or "snooperscope", were introduced by the US Army in World War II, and also used in the Korean War, to assist snipers. They were active devices, using a large infrared light source to illuminate targets. Their image intensifier tubes function using an anode and an S-1 , made primarily of silver, caesium, and oxygen and an electrostatic inversion with electron acceleration were used to achieve gain.

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