Thermal imagers read heat to create imaging.
Other night vision products take ambient light and amplify it to lighten up what is dark.
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It turns out that, other than asking witnesses what they saw in a multi-car collision, the best way to get nine stories from six people is to ask a roomful of cops what “night vision” means. Here’s what we do know: we want it. In October, 2011, when we wrote about the FLIR H-Series Thermal Imager, we heard from a lot of you who spoke covetously of this amazing technology. Almost as many said something along the lines of, “If only my agency could afford night vision.”
That got our editors wondering about what options are out there for agencies considering taking the plunge into owning the night. Best of all, prices of night vision and thermal imaging devices have come down significantly over the past decade. Meanwhile, quality’s gone through the roof. From our conversations with manufacturers, we believe that prices will continue to drop, perhaps from the current average of between $3,000–$5,000 to around the $1,000 mark in coming years and months.
But before we go into what’s out there (see sidebar, pg. 16), a little level-setting is in order. After all, some of the terminology used to describe specialty optics like “diopter adjustment” and “image polarity” can be rather overwhelming to those of us without pocket protectors. At times, the lingo seems to make it harder, not easier, to understand.
These technologies, though, are vital in our field. They add incalculably to both officer safety and investigative efficiency. They allow us to rule out some search areas and dig deeper into others. So it makes sense to break down the differences, point out some of the benefits of each technological approach and offer an explanation of how each system works without getting wrapped up in five-dollar words.
Night vision, truly, doesn’t differ much from any other type of photographic technology. Night vision devices, like conventional photo equipment, gather ambient light and light reflected off an object, and convert it to images and colors. It works with miniscule amounts of light to make things visible, in a way similar to how our eyes process images.
In technical terms, this is accomplished by taking light and converting it to electrons, then electrically and chemically amplifying the electrons. In the process, the technology changes and magnifies the contrast of what we’re looking at versus what’s around it. The higher the contrast between objects, the better our brains can process what we’re seeing.
The obvious advantage of night vision comes when light is low, but not nonexistent. Zero light conditions, though rare, don’t allow night vision to work. Interestingly enough, too much light will also prevent night vision from being effective. The U.S. military learned this lesson in 1992 during the invasion of Somalia. A landing zone had been aggressively leaked to the media by military publicists, and Marines arrived ashore to a blinding array of video klieg-lights, rendering their night-vision goggles totally useless.
The most prominent drawback of night vision equipment: It’s unusable in daylight, at dusk and dawn, and in complete darkness. Further, when identifying objects with the assistance of night vision technology, it’s still imperative that there be contrast. Camouflage objects will still be hard to recognize.
A great advantage: Night vision comes in many different flavors—from handheld units to helmet-mounted goggles and magnified rifle scopes, making it versatile in the field.
The current standard, Generation III, is literally good enough for government work, and we mean that in the best possible way. Gen 4 adds some features that the military decided it didn’t need (and also reduced tube life). Gen II and Gen I are, today, obsolete.
Infrared illumination is also a term that’s thrown around when talking about enhanced visibility optics. Infrared illumination (IR) is certainly not the same as night-vision technology or thermal imaging, and it offers a narrow range of benefits for LEOs.
With IR illumination, a specialized light source projects a beam of IR light—invisible to the naked eye—upon a target object. Specialized cameras that are able to “see” IR light then convert it into a visible image. Night-vision equipment can also see things that have been illuminated with IR light, and some units boast built-in IR illuminators. IR technology has been around for years. In fact, it’s the same type of light that our television remotes have used since the early 1980s to keep us conveniently planted on the sofa.
This is a feature on many consumer-grade video cameras like the Sony Nightshot line. The advantage of this type of equipment is its ability to produce a good amount of light that’s not visible to the naked eye—which means the bad guys don’t know you can see them.
The major drawback to this technology is that the infrared light source can only project so far (think of the range of your TV remote). This limits the number of applications it can be used for. Now, if you’re looking to conduct surveillance in a dark area, and you’re willing to set up a permanent or semi-permanent device, an IR camera may well be your answer. It’ll be hard to detect and can offer decent images for video recording.
The cost of these units is relatively low, but this technology tends to lack in portability and versatility, which limits its usefulness in most instances. However, when combined with Gen-3 or -4 night vision, these can be very powerful tools. The costs can be low enough to impress even the most penny-pinching of chiefs.
The third type of technology we use to own the night is thermal imaging (TI). This is a category of its own. It doesn’t “see” like the night vision, IR or consumer-grade video equipment. Instead, TI technology measures and graphically displays the difference in temperatures of objects in its field of view. Since there’s no need to bounce rays of light off of an object or produce its own light, TI technology steps in to the fight with a huge advantage.
As it turns out—and yes this is hard to admit—the fire service has widely known of and exploited the benefits of TI for years. It’s commonplace in many fire departments to equip every vehicle used for a fire response to have at least one TI unit onboard. In the fire service, the benefits of TI technology are well understood.
One reason firefighters respect this technology is its ability to produce images in total darkness and through smoke and walls: Physical barriers only prevent TI from working if it completely shields a heat signature. The greater the difference in temperature between objects, the more pronounced an object will appear to the user. The amount of contrasting colors of objects also has no affect on TI—your suspect could be hiding in a brush pile wearing a ghillie suit and he’d glow like a lab rat injected with weapons-grade plutonium.
Everything produces or holds a temperature. Depending on the insulating qualities of any given object, it will hold temperatures for different lengths of time or produce different amounts of heat. Unfortunately for the bad guys, people make their own heat. The harder they run, the hotter they get.
After a car is driven but has been parked for a bit of time, the car may feel cool to the touch. But a brake pad or engine block will glow hot for a long time when viewed through a TI unit. So will footprints on the ground, dripped sweat or blood, discharged guns—even recently held objects, like a thrown knife.
You can’t “own the night” without investment. Night vision, infrared illumination and thermal imaging all have advantages and disadvantages. Some combination of the three is the best option. But with budgets as tight as they are, this is a real challenge for most departments.
Bottom line: This fast-moving technology, like all technology, is an investment and a force multiplier. If you haven’t yet, it’s time to start weighing your options. The money you’ll save with one or two successful deployments would more than justify the cost of a quality unit, and the increased situational awareness could be a lifesaver.
American Technologies Network (ATN)
Night Vision Depot
US Night Vision