The Heat Is On

For buyers and sellers, thermal sensors see beyond night vision

• By Christopher Lindenau
• Jul 01, 2013

As police surrounded the suspected Boston bomber hiding inside a boat stored behind a Watertown, Mass., home last April, officers with a thermal camera peered through the hull and tarp to watch his every move. Unlike night vision goggles that detect visible light energy, thermal imaging cameras see differences in surface temperature. Thermal imaging “cameras” are more accurately called sensors.

The components include a display, detector, signal processing and optics. These cameras operate by sensing infrared energy emitted from a target—the alleged Boston bomber—and the target’s surroundings. The landscape seen through a thermal camera is a collage of black-and-white images, with the ones giving off the most heat seen as white.

Many in the security industry think of thermal cameras as something only useful to special operations forces, firefighters and police. Many believe the cost of this equipment is out of reach for practical applications. In fact, only 0.1 percent of the commercial security market uses thermal imaging cameras today.

Prices Drop

However, over the past few years, as the wars in Iraq and Afghanistan have wound down, post-war manufacturing capacity has exceeded military market demand, which has caused the price of thermal imaging systems to drop. For example, SP&T News reported that the volume of chips made for these cameras is causing prices for standard resolution (640x480) thermal imaging cores with fixed lenses to drop from $15,000 per unit to four figures. And, at ISC West 2013, some vendors announced models for around $3,000.

However, when people see stories of thermal imaging as an aid to capturing fugitives or as part of a commando raid, it reinforces the notion that the technology is beyond the need of commercial security. Practically speaking, that sentiment is wrong. Commercial security can benefit from not only adopting thermal imaging but integrating it into an existing network surveillance system for use with enterprise video management software.

Imagine a warehouse that uses floodlights, HD visible cameras, PIR (motion) sensors and ground loops along its perimeter to detect intruders at night. Perhaps the warehouse owners employ security personnel to monitor these physical security measures for intrusion, but these stop-gap measures are prone to produce false alarms and have limited efficacy for night detection. Visible cameras can’t spot trouble lurking under groundcover or beyond shadows. Motion detectors are limited by range and obstacles in the path of detection, and ground loops are difficult to install and can fail.

Complementing Visible Inspection and Cameras

In terms of cost versus efficacy, there is no comparable alternative to thermal imaging for detection. At night, the next best alternative is not even close. Whole fence lines, wide field areas, areas with architectural or foliage obstructions can use thermal surveillance for intrusion detection. Thermal imaging offers a level of detection that complements visible inspection qualities and HD visible cameras during the day to provide an overall better picture of a facility, a real value to security personnel who cannot be everywhere at once.

In the commercial sector, power generation plants, airport fence lines and data centers are using thermal imaging to spot intruders. Due to the limitations of visible camera technology, and labor and wiring costs to install individual cameras—many customers are now looking for cameras that employ both visible and thermal cameras in the same system—a dual imaging approach. In recent physical security upgrades at a major metropolitan airport outside of New York City, dual imaging was preferred over any other measure to detect perimeter intrusion. When used with software analytics, the result is both potent and cost effective.

The U.S. military first used thermal imaging cameras for operations in the late 1960s. Like anything the military procures, suppliers must meet exacting standards. For example, thermal imaging systems for military use must meet specifications for temperature (from -58°F to 165°F), vibration (i.e., HumVee Standard) and surge protection (i.e., Mil-STD-810G) beyond what most commercial thermal imaging cameras require. As commercial security professionals explore a dual imaging approach, there will be increasing pressure on commercial systems to meet militarygrade standards because buyers will want to ensure their investment lasts. There also will be pressure to develop military-grade, network-ready thermal imaging systems as the surveillance industry moves toward the use of Ethernet switches and software, versus digital recorders and hardware.

A Networked View of the World

Although analog camera systems still claim up to 80 percent of the industry’s installations, IP and networked cameras are rapidly gaining ground. One reason is the ease with which installers can add new network cameras to an IP network. If, for example, an integrator has to add more network cameras, then a technician can run cable from the nearest switch. One switch commonly supports up to 64 cameras, and can be located within 100 meters of them, simultaneously providing power through one cable.

By contrast, an analog camera installation may require a technician to run video and power cables from each new camera back to a digital video recorder and a centrally-based power supply—a significant increase in wire and installation cost.

With this advantage in mind, traditional IT-based companies are increasingly entering the security industry with new product offerings. such as software video management platforms, powered PoE switches and video recording solutions. This is driving corporate IT departments to become part of the evaluation process for the adoption of new products like networked thermal imaging systems. Whereas with analog systems the director of physical security chose new surveillance technology on behalf of the company, today network cameras systems empower the CTO or IT director to be the key decision maker. And that requires providers of security imaging systems to show expertise in both optics and networking.

Adapting Thermal Imaging to Fit Today’s Platform

Thermal imaging system suppliers must adapt their technology to fit into an array of complex IT platforms, and that concept is not always easy to grasp for companies that specialize in developing camera systems. Network camera makers have to ensure that the software they sell with their cameras will integrate with the network firewalls, software and hardware that a corporate IT department has already put in place. This is a different mindset. But, suppliers adopting this point of view will help the customer trying to coordinate a purchase between his security department and IT group.

For example, modern enterprise software requires standard protocols that enable a technician to integrate a camera system with a network. The network protocols are simply the mechanism by which systems, servers and devices talk to one another. Common protocols already exist for cameras, and these standards are being adopted by thermal imaging systems, too.

One such protocol is ONVIF, which was created by global industry group Open Network Video Interface Forum. The standard aims to facilitate communication between all physical IP-based security products. The ONVIF protocol is already commercially available on some network thermal cameras. Standard protocols like ONVIF will allow manufacturers of thermal cameras to integrate with the customer’s chosen video management software.

Of course, analog thermal cameras also exist, and integrators can encode these analog thermal imaging systems to make them IP-ready, too. In fact, for the majority of security appliances using analog technology, most commercial encoders will accept an analog thermal camera and create an IP format for it.

But let’s say a company has built its security system on an analog footprint and wants to use a network thermal camera. The integrator would recommend a third-party encoder here, too. With the encoder, the integrator can then migrate to an IP video stream.

The beauty of ONVIF lies in the fact that purchasing an ONVIF-compliant encoder and integrating it with an ONVIF-compliant camera provides interoperability. In 2011, ONVIF developed a profile concept. This profile simplifies the identification of interoperable products, and it lets customers easily identify specific features by profile.

“The primary benefit of our Profile concept is knowing that when two products bear the Profile C [access control] or G [video storage] mark, the same as what is already available with Profile S [video streaming] conformant products, they will work together,” said Per Björkdahl, ONVIF chairman. “Rather than trying to figure out whether one version of the ONVIF specification is compatible with another, or which features of the product might interfere with interoperability, seeing that mark ensures a successful interface.”

There is much to be excited about with network appliances, especially thermal imaging systems. But there is one major shortcoming. All of that compression that is part of delivering a network image via camera causes latency. The degree of latency may be a matter of milliseconds, but it’s there. That said, there are companies that have achieved a degree of latency that is now less than 150 milliseconds. Companies that know how to improve the compression algorithm to decrease latency can overcome this shortcoming of network appliances.

What’s Next for Commercial Security?

Today, thermal imaging systems are sold with a standard resolution of 640x480, which makes 1,280x720p the next likely thermal imaging system for commercial applications. While these HD imaging systems are available, they can cost upwards of $50,000 but expect to see such imaging systems come down in price. Typically you will see HD thermal imaging systems in the military, aboard a tank for targeting enemy combatants.

The cost of these systems is in the production of the lens, as well as the camera core, which processes the image. While producing the core for an HD thermal imaging camera can be expensive, the greater cost is the lens. To see the transfer of infrared light emitted from an object, lens manufacturers have to use a significant refinement process. These lenses range in price from fixed-lens configurations, with a fixed focal plane, to continuous zoom lens. And the price point jumps by a factor of four from fixed lenses to continuous zoom lenses.

Whenever manufacturers increase the resolution of the chip inside a camera, the price of the camera core will increase by a factor of five. Consequently, the increased size of the imager and the lens will also mean a price increase by a factor of five.

Beyond 720p is 1080p. A 1080p thermal imaging system for commercial use is still something we have yet to see. The size of the imager alone would be large and the lens would be comparable in diameter to a basketball, making the system too big for commercial applications.

With the advent of HD thermal technology for commercial applications, imaging-system makers will give customers a way to not only detect, but also identify threats. The distinction is important, and it’s based on the Johnson criteria. The Johnson criteria give us a way to understand the performance of visual devices, such as imaging systems. Simply put, criteria defines “detection” as observing the presence of an object; whereas “identification” is not only spotting a car but also seeing that it’s a VW Bug.

Thermal imaging technology offers a level of detection and identification that will complement your existing surveillance system when the heat is on.

This article originally appeared in the July 2013 issue of Security Today.