Night Vision Devices
The history of much the technology used by consumers has its birth in the military. They are responsible for the Internet, GPS, and freeze dried foods, just to name a few things. Night Vision Devices (NVD) is no exception. We are not speaking about the toys that your children can play with, but the real McCoy.
Historically speaking, nighttime warfare operations are preferred to daytime so that the troops can remain under the cover of night, belaying their locations until the last possible second. This was quite difficult in past centuries, as the human eye is quite limited in the dark and there needed to be a better way to see than starlight or blowing your cover with the use of searchlights and flashlights. The United States Army has engineers and researchers constantly at work to discover and expand upon technologies to procure optimum operational environments for troops. CECOM began in the 1950s to try to make the lives of soldiers easier to plan by.
There are ways to capture available light through electro magnetic radiation outside the eye's range with the NVDs. Using invisible light gives goggles and scopes the ability to see in the dark. At night or in low visibility the night vision technology allows the soldiers to see, maneuver and fight. There are two types: image intensifiers and thermal devices. Thermal devices work by way of sensing the differences in temperatures in the scene in front of the troops. The FLIT (Thermal Forward-Looking Infrared) detector option is what is used on combat vehicles and helicopters.
Using light intensification and available light, the image intensifiers augment the light by 2000 to 5000 times normal vision leading to the scene in front of the troops to be displayed by way of phosphorous screens with technology similar to imaging on a TV screen. With the eyepiece in place, it is possible to magnify the images for better clarity when viewing. The phosphor screen is green in color to aid the eye in compromising the scene in front of the soldier. The human eye discerns more levels of green than any other color in the visible spectrum.
Different magnifications are available on different lenses, so it would depend on which was being used wit the NVD devices. The range, however, would be anywhere from four hundred to with a few feet away from the troops. Missions can be achieved without any illumination by using only the image intensifiers. This keeps costs down with small, low power and lightweight sizes for easy transport.
Do not forget as you wear the goggles, you will experience tunnel vision since all peripheral vision is cut off within the eyepiece. Constant movement will allow you to detect your surroundings. Judging accurate distances can become tricky, as larger subjects seem closer than they really are and vice-versa. Vision drops from 20/20 to 20/25. The good news is, you can see. The military forces have the ability to work under the shroud of darkness, much like combatants do, allowing for a better chance to capture and conquer when necessary. The FLIRs help dramatically in locating human energy from within a heavy cover, allowing for the direction of troops to specific locations to carry out missions. Rescue missions also have a better chance of success with the use of the Night Vision Devices.
Source by Craig Mooney