Night Vision Technology: Weighing the Advantages|
Although there is more than one way to see in the dark, there is without a doubt a great deal of qualification regarding the merits of each method when they are compared with each other. Every type of night vision technology available creates a common advantage in that they provide a means of visual perception in otherwise lightless conditions. Whether the technology involves amplification of available or ambient light, or relies on radiated infrared energy more commonly known as heat, it produces a visible image of otherwise obscured or invisible sources. The potential such technology provides has not gone unnoticed, and indeed night vision has been heavily developed and adapted to a wide range of applications ranging from military operations, to law enforcement, to private security, and even recreational hunting.
The most commonly recognized form of night vision is based in light amplification technology. Introduced in World War 2 and heavily developed and improved since, this is the kind of night vision most commonly seen in movies and on television and made famous by the same. The images are always green and somewhat strangely contrasted, although not detrimentally so, and depending on the type of device show amazing detail even in almost lightless conditions. While the images produced by this technology are not as clear or detailed as those produced by normal daytime imaging devices, they are very close and lack only true color representation. These devices take any available light, whether it is starlight, moonlight, or simply ambient light from distant sources and amplifies it thousands of times. More importantly, these devices typically sense and amplify light across both the visible and invisible light spectrum.
The other type of technology most commonly associated with night vision is thermal imaging. This type of night vision technology is not true night vision, only because it can be effectively utilized in daylight as well as nighttime conditions. This technology relies on sensing equipment that detects the heat radiated by objects and uses the contrast between sources to form an image. This type of technology is particularly effective for general location of objects or persons that may be obscured or camouflaged. While an object or person can be hidden by leaves, netting, or some similar form of obscurant, the heat they radiate cannot so easily be masked and is easily detected by thermal imaging devices. Thermal imaging produces images that can show an amazing amount of general detail making identification of persons or object possible, but it lacks the ability to produce fine details such as facial features or lettering on surfaces.
Because of their inherent differences, these two forms of night vision technology are not wholly interchangeable and each offers its own advantages and disadvantages. Much of each type’s practicality hinges upon the needs of the user and the surrounding conditions. While light amplification devices are effective for very low light conditions and produce finely detailed images, they still require some amount of light to function. Thermal imaging devices on the other hand do not require any light whatsoever and can be used effectively in total darkness, however, their effectiveness is limited by interference between strong heat sources within close proximity to each other and the inability to produce fine detail.
Light amplification devices hold a distinct advantage over thermal imaging despite their need for some amount of light to operate. The problems with low or no light levels can be mitigated or removed by the addition of external light sources that produce illumination in the invisible spectrum. Almost all light amplification devices are sensitive to the infrared end of the light spectrum. Since infrared light is invisible to the naked eye, the covert nature of the technology remains uncompromised unless those being observed have the necessary equipment to detect the infrared light being used and are alert to the possible presence of light amplification devices. The direct advantage comes from light amplifications ability to produce highly detailed images. In many critical covert operations, it is often not enough to simply locate specific persons or targets. Positive recognition of a person’s identity is often mandatory to assure the safety of non targeted personnel as well as guarantee the successful acquisition of an intended objective. Thermal imaging is currently incapable of such detailed identification. Although thermal imaging has excellent target acquisition abilities, it lacks the ability to distinguish facial features or other fine details that may indicate the presence of a weapon.
Night vision that relies on light amplification also has the ability to be greatly enhanced with supplemental illumination in the form of infrared light emitters. Infrared emitters like the Larson Electronics 240 watt IR LED Light Bar can greatly improve the effectiveness with which light amplification night vision is used. In conditions where there is little to no light, these emitters allow night vision to be used without any degradation in image quality. In normal low light conditions, these emitters greatly improve the effective range of night vision devices as well as the quality of the images they produce. In situations such as military convoy operations, the securing of buildings and locations, management of civilians among combatants, operations at sea and more, these emitters can make the difference between unnecessary casualties and successfully completed objectives.
Infrared light emitters vary in their design and effectiveness as well. While older emitters may rely on incandescent lamps and filters to produce infrared light, they typically consume a lot of energy and create a great deal of heat. Newer emitters rely on LED technology to produce infrared illumination and produce light only in that spectrum, removing the need for filters or incandescent lamps. These emitters typically can be run on a variety of voltages, making them ideal for portable or mobile applications. They also use very little electrical power, making them excellent choices for applications such as vehicle mounted systems where power availability is limited. LEDs are quickly making any other form of IR emitter obsolete and represent the best way to augment light amplification technology.
Current night vision technology is improving by leaps and bounds. Although both thermal imaging and light amplification technology continues to improve and offer great advantages over those unequipped, neither is perfect for every application. As the technology progresses, new developments promise to integrate both thermal and amplification abilities into a new breed of night vision that produces the best aspects of both in one technology. Until this new technology is perfected however, only infrared light amplification provides the fine imagery detail that allows for the positive identification of targets among non targets.