Night vision is a pretty specific term – it is simply the ability to see in dark or low-light situations. Generally, at least associated with many other animals, humans have poor living night vision, originating the wish to see in the dark challenging to fulfill.
Challenging, but not impossible – at this point, we have many diverse night vision technologies used for different objectives.
Initially promoted for military use, night vision technology allows one to acknowledge in the dark. Unfortunately, we, humans, possess poor night-vision compared to many animal varieties. But now, with proper facilities, we can understand a person holding far away on a moonless, overcast night! In the 21st century, we have come an extended way in developing night vision technology since its discovery. However, it is applied mainly for defense purposes, as the law often prevents its utilization within experimental or civilian realms.
Night Vision: Operating Principle
Night vision technology operates in two various ways, particularly Image Intensification and Thermal Imaging.
- Image intensification: This technique involves ambient light amplification. It operates by being able to recognize low levels of light and amplify them. For example, when photons which are mini energy packets that make up light, enter an image enhancer, they first beat a photocathode layer that releases electrons. Next, these electrons hit a second layer called a microchannel plate which multiplies the electrons before they hit the phosphor screen, which converts them back into the light because there are now so many more electrons that we get a brighter image.
- Thermal Imaging: This procedure entails capturing the upper portion of the infrared light spectrum transmitted as heat energy by objects rather than reflected as light. Temperature is identified by capturing the various levels of IR radiation. Although we cannot detect the light in the dark, it can be sensed as heat, given the intensity is high enough.
Night Vision: Technology
Technology has awarded us two means to view in the dark: image enhancement or thermal imaging. Image enhancement arrives in mind first for most people when they consider “night vision,” and it’s the technique employed by night-vision goggles. The comprehensive class of devices that use this procedure is termed NVDs or night-vision devices. Image enhancement includes using an image-intensifier tube component to collect a minimal amount of light from a broader spectrum than the human eye can perceive and then amplify it until the naked eye behind the goggles can see.
Thermal imaging devices operate by capturing high-frequency infrared light (IR) sooner than visible light. IR in frequency as mentioned above range (3-30 microns) is recognized as thermal-IR. However, it varies from other frequencies in that instead of being followed off of an object, thermal-IR is emitted by that object due to the action of that object’s atoms. Thermal imaging devices catch the thermal-IR light and scan that light with a collection of IR detector elements. These translate the IR light as a sort of heat-map and then transform it into electrical impulses. These drives go through the device’s processing unit, converting the data into an image and sending it to the display.
Night Vision: History
Like many modern technologies, night vision devices were designed to aid us in waging wars. Just before WWII, Germany revealed the first simple IR devices, and the Allies explained their own in response. At this point, these devices could magnify light by around 1000x but were so huge that they had to be mounted on trucks.
In the 40s and 50s, the US Army operated with the RCA (Radio Corporation of America) to improve night vision technology. Thermal imaging made some considerable advances in the 1970s and proceeds to improve. At the beginning of the 1990s, NVDs were mainly used by US forces during Operation Desert Storm, providing the US with another considerable advantage. Contemporary NVDs can magnify light by more than 50,000x, and they proceed to grow more potent as science constantly makes improvements.
Night Vision: Devices
- Scopes – Monocular device, handheld or installed on a weapon. Goggles – Binocular, mounted on the headgear.
- Cameras – Used for capturing images/ recording videos.
Night Vision: Advantages
- No particular skill is required.
- Compact system.
- Reduction in accident cases.
Night Vision: Applications
The night vision was initially developed for warfare. However, information becomes even more valuable when lives depend on it. The locations of enemy troops and the experience of your surroundings are two of the most useful types of information. The ability to collect this information at night, when your enemies may be blind, is a huge advantage. The military uses various NVDs for these purposes – handheld weapon scopes, sighting scopes, and night vision goggles being the principal three.
Army use isn’t the only utilization for night vision, though. Night vision cameras are often utilized for security, as well. They are instrumental in lowly-populated regions where there is less light. Law enforcement and the military also both accept NVDs in helicopters for inspection when essential.
Thermal imaging devices can be utilized for many of this applicability as well and more. NVDs provide an amplified view of what you would typically see, although it’s only in one color. On the other hand, thermal imaging devices pick up heat, making them useful in different ways. Since thermal-IR energy is released rather than reflected, these devices can work in the total absence of any light. This makes them especially useful for firefighters, who may see themselves going into a construction that is not only dimly lit but also suffocated with smoke. Firefighters wear a helmet-mounted thermal imaging device that drops down over one eye, sort of like a monocle, allowing them to see in the cold conditions they are often faced with.
Like night vision, thermal imaging is helpful for security, as it can pick up human heat signatures in situations where it might be hard to see what’s going on even with an NVD. Thermal imaging is also beneficial for law enforcement and the military. Heat signatures can be a lifeless giveaway of someone’s neighborhood, whether “someone” is a suspect or a combatant.