A Tale: Night Vision Goggles
Night vision equipment and applications offer a large range of uses, whether serving in the military, doing surveillance or law enforcement work; detective, entertainment or security work; or just hunting and taking in all the great outdoors and wildlife.
The three types of night vision equipment and applications are scopes/monocles, goggles/binoculars, and cameras. These pieces of equipment require at least one of the two different technologies, thermal imaging and image enhancement to work. These are both part of the infrared light spectrum but occupy different points along it.
Thermal imaging uses the upper portion of the infrared light spectrum, infrared light is emitted by an object’s heat rather than just being reflected as light. The hotter the object, the more light that is emitted. Warmer bodies or objects such as humans and animals emit more of this particular light than the colder objects such as trees, rocks and buildings. Thermal Imaging works with the use of a special lens which focuses the infrared light which is being emitted by all of the objects within view. The focused light is scanned by infrared-detector elements and creates a detailed temperature pattern called a thermogram. The thermogram is then translated into electric impulses which are then sent to a signal-processing unit. This signal-processing unit then sends the collected information to the display. The image is created by the combination of all of the impulses from all of the elements. Un-cooled and cryogenically cooled are the two categories of thermal imaging devices. Un-cooled is the most common, while cryogenically cooled is more precise but much more costly and susceptible to damage.
In Image Enhancement, very small amounts of light, even those at the lower end of the infrared spectrum which cannot be detected by the naked eye, are collected. It is then amplified so that the image is then easily viewed. NVD’s, or night vision devices, require a special tube called an image-intensifier. The purpose of using the cylinder is to gather and collect light waves and then increase the amplification of infrared light waves and visible light waves. A tool called an objective lens will capture certain types of light waves such as ambient light and near-infrared light waves. This collected light is then sent into an image-intensifier tube. The output voltage to the image-tube components from this tube is 5,000 volts. The component of the photocathode is the image-tube. The job of the photocathode is to convert the photons of light energy into electrons. One of the devices used in image enhancement technology, also frequently known as night vision, is an ocular lens which allows the image to be viewed and focused as well as magnified. the images can be pass through the eyepiece to be expanded and fixed the shadow on a mirror or on an electrical display The ocular lens has the capacity to directly display images.
With the use of the proper equipment, users of night vision goggles and equipment, will be able to see a person standing 200 yards away, including the ability to see that person through such conditions as moonless and/or cloudy nights, fog and pitch blackness.
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