August 30, 2018

When it comes to law enforcement, perhaps no piece of equipment is more fun to think about and use than night vision and thermal imaging technology. You know night vision, those grainy, greenish pictures you see of law enforcement looking for a suspect at night on TV or in the movies. And we’ve all seen military movies where thermal imaging is used to find out if the bad guy is hiding in the building and in what room or alcove -  the reds, yellows and greens from the heat of the person clearly visible and indicating the target.

 This equipment is more than just movies, TV and fun though. For law enforcement, it’s a vital tool that can be used in a variety of ways, and which helps keep officers safe. Let’s take a look at both night vision and thermal imaging technology, and how it can help your department and your personnel.


 Night Vision

Night vision optics work by taking in small amounts of visible light and greatly magnifying it, then projecting those images on a display. Cameras that use this technology are limited – the same as the naked eye – by the amount of available light, so that if there isn’t enough available, you won’t be able to see well.

 These cameras detect reflected light energy from elements like the surroundings natural light, heat and other forms. Because it relies on reflected light, however, its performance is limited by the amount and strength of the light reflected, so the less amount of available light, the less clear and helpful the image will be.

 Night vision and thermal imaging are not and cannot be used for the same purposes. Night vision can be used to search dark buildings. Often times, using a flashlight or the building’s interior lights can alert suspects that you’re there, so night vision allows you to search while maintaining your cover, thus giving you the tactical advantage and promoting your safety.

 Night vision may also be used for wide area searches – for instance, an open field. In this type of environment, you could practically be standing over your suspect and not see them, but with night vision, you are able to easily spot them and proceed as needed.

 Other potential uses for night vision include monitoring the perimeter of tactical operations and surveillance.

 Night vision equipment is not limited to what we most often think of when envisioning it – goggles – but instead, can be split into three categories: goggles, scopes and cameras.

 Goggles

These are what we tend to most often associate with night vision – the standard binocular (two eyepieces) with either a single lens or stereo lens. Because these are worn and not handheld, they are an excellent choice for constant viewing like moving around in a dark building looking for a suspect.


 Scopes

These are monocular (one eyepiece) and are generally either handheld or often mounted on a weapon. The advantage of a scope is that, because it’s normally handheld, you’re able to get it closer to specific objects for better close-up viewing.

 Cameras

The benefit of a camera featuring night-vision technology is that the image can be sent to a monitor at another location for display.

 What to look for when purchasing night vision equipment

It’s important to note that traditional light amplification falls into three categories:

  1. Generation One
  2. Generation Two
  3. Generation Three

 The categories we’ll focus on are Gen Two and Gen Three. The classification system is based on what internal systems are used in the night vision equipment. They all use a photocathode which converts photons into electrons, which are then converted again into the visible image we see on the device.

 There are several factors to think about when deciding between a Gen Two and Gen Three optics device. The first is cost. Gen Three devices will cost significantly more than Gen Two, as they offer a much clearer image. But the difference in image quality can be thought of like a standard definition TV versus a high-definition TV. The standard will suit many needs and does a fine job, but the HD is obviously clearer and therefore better. If you decide on a Gen Two, you must alter your expectations and be prepared for that SD quality.

 The second factor to consider is the durability and lifespan of the device. In order to maximize light transmission in Gen Three devices, engineers thinned the internal dimensions, meaning their delicate internal parts can crash against one another if there is recoil from being a scope on a rifle. If, however, you choose goggles as opposed to a scope, then this factor shouldn’t matter.

 But also note that because of their higher quality, and barring any recoil incidents, Gen Three devices usually average double the lifespan of Gen Two – roughly 10,000 hours for Gen Three to between three and 5000 hours for Gen Two.

 Purchasing night vision equipment is a big decision with a hefty cost associated with it, and therefore, should be carefully considered. Ideally, you want to choose the least expensive option that meets all of your needs.


 Thermal Imaging

Thermal imaging equipment utilizes forward-looking infrared (FLIR) technology, and is extremely easy to use. Basically, they require no training or interpretation to use. The images they produce are clear and easy to understand.

 How does it work? Thermal imaging works by detecting the difference in temperature between objects in the background and foreground. The major advantage of thermal imaging is that it does not rely on any source of light to produce an image, but rather on the heat produced by objects, whether animate or inanimate. For instance, a boulder will produce an image because of the heat it has stored from the sun.

 Because thermal imaging does not rely on any source of light, it can produce an image even in the darkest of circumstances, and can also see through elements like rain, fog and smoke.

 This is by far the biggest benefit of thermal imaging technology. It does not have the drawback of night vision technology of needing a certain amount of light to produce an image. This holds especially true for when looking for a person at night. Without a certain amount of light, night vision won’t work properly, but with thermal imaging, the difference between human temperature and any other object will produce a clear image of the person. This can also be very useful during a search and rescue mission.

 Other uses for thermal imaging include searching for vehicles trying to elude pursuit (the hot car stands out clearly), aiding in accident investigations and recreations, and even identifying any disturbed surfaces like walls that have been repainted to hide evidence. 

 Once again, thermal imaging technology and devices are extremely expensive, and great care should be taken to reflect on your department’s needs so that you can make an informed decision and a wise investment.

 Armasight Dark Strider 5x Gen 1+ Night Vision Binocular

The Armasight Dark Strider night vision binoculars are similar in size, weight and feel of a normal pair of binoculars, making them convenient to carry with you and store. They feature a built-in adjustable infrared illuminator which helps ensure they operate efficiently even when in total darkness. Simple control buttons and eyepiece-only focusing optics make them easy to use.

 Armasight Q14 TIMM 336 Thermal Imaging Multipurpose Mini Monocular

Armasight has created the lightest fully multi-functional thermal imager on the market today (it can be concealed in a shirt pocket). Its compact size belies its high power and clear images. A simple, 3-button control means that it’s easy to use, and comes with features like 4x digital zoom, integrated digital compass, and integrated laser pointer.


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