The Truth About Thermal Imaging

Do you know the difference between thermal imaging and night vision? This is a pretty relevant question, considering that most people often get the two confused. However, SSI sought to distinguish the two technologies in the “Video Continues to Enhance Its Security Image” feature found in the January 2011 issue.

In the feature, editors interviewed a dozen top technology providers, who were asked to identify the latest and greatest video surveillance technologies for 2011. Among those consulted was Andy Teich, president of commercial systems, FLIR Systems Inc. Having worked with thermal imaging equipment for 28 years, Teich wanted to clear up the misconceptions between thermal imaging and night vision technologies. Keep reading to learn the difference and see how by offering thermal imaging technology, integrators can set themselves apart from the competition.

What is thermal imaging?

Andy Teich: Thermal imaging allows cameras to see heat instead of light. [These cameras] look in a different wavelength. Your eyes see in the spectrum of visible light, and if you go to increasingly longer wavelengths of light, you get into the thermal spectrum. Most of our cameras operate in the eight-, 10-, 12-micrometer spectrum, so you’re seeing heat, not light, and it’s an energy that’s invisible to the eye.

The reason that it’s beneficial to collect energy and imagery for the security user in that space is twofold. No. 1 is every object has a thermal signature. The second [reason] is thermal energy passes through the atmosphere better than visible energy does. For example, you can see through smoke, light fog, light rain and light snow — some of the things that tend to hinder visible cameras; however, thermal cameras can deal with it.

The third and most obvious reason is that you can see in total darkness. A thermal image looks exactly the same during the day as it does at night. In fact, many times when you’re looking at a picture, you can’t tell whether it’s day or night. That’s the key reason that people would be interested in thermal cameras. It has a true 24/7 capability.

What about color night vision technology? How is that different from thermal imaging?

Teich: It is an extremely low-light imaging technology that still provides true-to-life color detail. The technology that is underlying our color night vision product is called electron multiplied charged coupled device [EMCCD]. Most security cameras that are being used today are CCD cameras. What that does is puts an electron multiplication circuit in the detector or sensor that allows you to see at much, much lower light levels than you can do with conventional CCD detectors. There has to be some light, unlike thermal, which requires no light, but you can still get very good quality color imaging.

There are two types of night vision technology that are prevalent today. One is what the security industry commonly calls infrared, which is not the same as thermal because it’s running at shorter wavelengths than thermal. It’s basically a CCD camera that has been opened up to slightly longer wavelengths of light. What you get is a monochrome image [a black-and-white image], but it typically needs to have illumination. It needs to have some sort of lighting, and what frequently is used is an infrared illuminator. So, there are LED IR illuminators that are frequently used in that scenario. They will provide imaging in low-light situations; however, the drawback to those things is twofold. They tend to be very short range, so the typical 100 feet or so is the maximum range that they can view. They are very intolerant to obscurance. Smoke and light fog tends to reflect the light of the illuminator that is being used, so they do very poorly in situations where there is obscurance.

The second type of night vision technology is image intensification, where the imagery looks green. That tends to be pretty expensive; it can sell for thousands of dollars. It uses a light amplification technology that consumes a fair amount of power, and it also does not do well with obscurance. It requires some level of ambient light, but it is also very sensitive to ambient lighting in the scene. An example of that is if you have a scene that is mostly dark, but there is one streetlight in the scene, an image intensifier can’t deal with that because the one street light just totally dominates the capability of the censored image, and as a result, you can’t see anything around it. They have very small contrast capability and very little dynamic range, which is the ability to see low light and a higher amount of light at the same time.

So that’s kind of the background of those technologies and that’s kind of why the drawbacks of those technologies are the reason why the market has an ample space for thermal imaging and color night vision technologies today.

What is the latest and greatest in thermal imaging and color night vision for 2011?

Teich: There are two trends in the thermal imaging space that one will see take place in 2011: price and resolution. The first one is continuing cost lowering. Coming into 2011, the least expensive thermal imaging camera for security applications was around $3,000, and I’ll think you’ll see those price lines approach $2,000 [this year].

The second [trend] is increasing resolution. In much of the same way that you think about resolution for digital cameras, it’s the same thing for infrared or thermal space. Today, the common thermal imaging cameras are 320 X 240 resolution. We have just begun offering a full line of 640 X 480, and I think you’ll see that dominating our product line is 2011.A third thing I would add is an increasing level of IP functionality and onboard analytics.

What are the challenges the technology faces?

Teich: Price is an obvious one [as mentioned before]. You can buy an IR camera with an illuminator for a few hundred dollars, but some of the least expensive thermal cameras are around $3,000.

The second point is awareness. A lot of people just don’t know what thermal is or does or what the advantages are. If you think about it, bad things tend to happen at night and also when there may be obscurance present. The combination of darkness and then obscurance is something that happens frequently, and it just takes out most conventional security industry imaging technologies.

If you’re protecting a critical asset, such as a data center, a bridge, a dam or nuclear power plant, you don’t get the day off because it’s dark out, or it happens to be foggy that day. The security system still needs to function just as well as it did when it was bright and sunny outside. That’s the message that thermal delivers, and we’re just working hard to evangelize that message.

Why should installing integrators care about thermal imaging? What kinds of opportunities will they get from both services and market niche standpoints?

Teich: Differentiation. An integrator that carries thermal imaging is a differentiated integrator. These guys struggle because the conventional CCTV market is a commoditized market, so everybody has access to the same equipment. It’s all about price; there are
a gazillion CCTV camera manufacturers. It’s very tough for somebody in a commoditized market to make money.

However, if you’re up on emergent technologies like thermal imaging and color night vision, and you bring that solution to your customers, you now have a differentiated offering that can solve problems other integrators likely can’t.


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