Thermal Becoming More Viable

While video surveillance remains a robust market segment for the security industry, camera commoditization and eroding hardware margins have been a key pain point for systems integrators.

The so-called “race to the bottom” has forced the security channel to expand the video solutions and services they offer in order to differentiate themselves, and one of the technologies integrators have been adding to their portfolio is thermal imaging cameras – for good reason.

Twenty years ago, thermal imaging was still a military technology that critical infrastructure organizations could not afford; however, the commercialization of thermal technology has significantly decreased the cost, making room for the introduction of more options – including thermal cameras with uncooled cores and advanced analytics. Thanks to greater market availability and lower prices, thermal cameras are now a viable surveillance and detection option for airports, utilities, commercial institutions, correctional facilities, and other large enterprises.

“All facilities have perimeters to protect and monitor,” says Noel Tamayo, security systems designer at Convergint Technologies. “With more competition, different manufacturers now in the marketplace and prices going down, the deployment of thermal cameras in perimeter security is becoming common, and the features of thermal cameras are becoming more advanced as the race continues.”

In addition to their usefulness as a perimeter security solution, thermal cameras also yield substantial infrastructure and labor installation cost-savings for integration firms, ultimately increasing margins and driving the bottom line.

Low-Light and Thermal Options

Safeguarding the perimeter of any facility requires 24-hour monitoring, meaning the surveillance or detection solution needs to perform well in low-light or no-light scenarios. Low-light cameras, infrared illuminated (IR) cameras and night vision goggles (NVGs) are common solutions for these applications. Here’s a closer look at each:

Low-light cameras – also called day and night cameras – are known for their ability to electronically and automatically adjust lighting capture settings to produce optimal video images based on the time of day. These cameras often use IR cut filters to “cut out” IR illumination during the day, which allows for color images for identification and verification purposes. At night, the filter is removed entirely to allow for the maximum amount of visible and IR light to reach the sensor to produce a monochrome image. These cameras are entirely dependent on lighting conditions – too much light or no light at all will result in unusable images. In either case, the amount of visible light available drastically affects the image.

IR cameras, another night vision alternative, have a lens that is typically surrounded by LEDs. These LEDs emit a beam of near-infrared energy to bounce off objects in its field of view, enabling the image sensor to create a picture. The challenge with IR cameras is distance. The reflected IR light can only reach so far, restricting these cameras to short-range applications.

Night vision goggles and cameras capture visible light photons. As the photons penetrate a photocathode tube, which acts as an image intensifier, they are converted to amplified electrons that pass through a phosphorous screen and converts them back to visible light to create a picture (often in a greenish hue). NVG devices need the right amount of visible light to function and do not work well when there is still ample light outside, such as at twilight; however, no light, or conditions that block light such as smoke, will render these devices useless.

Thermal cameras produce video surveillance images based on the measurement of the electromagnetic heat radiation emitted by all objects and individuals. They are unaffected by bright lights, complete darkness, foliage and light fog. They pick up all differences in heat, no matter how small, to produce images with high contrast, which are essential to the successful performance of video analytics and intrusion detection. “Thermal cameras are better than night vision devices because they produce images from a heat source, while night vision devices depend on visible light,” Tamayo says. “All security projects that I’ve handled that deal with perimeter protection use thermal cameras – the majority in oil and gas industries, data centers, mines and power stations where perimeter protection is highly required. It is usually coupled with a second layer of protection such as fence sensors, microwaves and PTZ cameras – or combination.”

Fewer Devices for Large Perimeters

What once may have required six visible light cameras to achieve the desired detection range can now be done with a single thermal camera; and because of their long-range detection capabilities, thermal cameras can be a viable alternative to fencing.

“Thermal cameras can shoot long distances – reducing the number of cameras required to cover a perimeter,” Tamayo says. “A thermal camera can detect a human as far as 700 meters; and in certain areas where fence installation is not possible, a thermal camera can be a good substitute.”

An example would be ports and oil refineries that have hundreds of acres of water or land to monitor. Creating a “virtual fence” using thermal imaging and video analytics for intrusion detection may be a more feasible, affordable option than installing a physical barrier around the entire perimeter.

By designing and installing a system that uses advanced solutions like thermal cameras that require fewer infrastructures, integrators help their customers save money; this goes a long way as far as trust building and customer retention. Lower camera counts also mean integration firms can minimize their labor installation time and expenses and thus increase overall project margins to positively impact the bottom line.

Deployment Best Practices

Generally speaking, when installing a thermal camera, the field of view should be parallel to the fence line or perpendicular to any individual moving across the perimeter. This ensures that any approaching target will move horizontally from one side of the camera to the other and be visible from “head to toe” – optimizing detection while minimizing false alarms.

In applications with multiple thermal cameras, the fields of view should overlap to minimize dead zones. “One best practice I can suggest when implementing thermal cameras in a multi-layered perimeter solution is to make sure that the blind spot is minimal,” Tamayo says. “For example, installing two thermal cameras facing each other covering each individual blind spot; or, use the ‘chase method’ – where a camera from the back covers the blind spot of the front camera. If possible, assign and align the thermal camera infrared zone with other perimeter system zones –that enables easy verification of the source of an alarm.”

Beyond camera placement, choosing a lens with the right focal length is vital. For cameras with greater focal lengths, targets appear larger, which is ideal for video analytics at longer distances; however, the field of view is narrower. On the other hand, lenses with smaller focal lengths have wider fields of view. To determine what lens is best for the application, the integrator must evaluate what is most important for surveillance and detection: distance or width.

When setting up other security system parameters such as target size and classification, integration companies should take advantage of installation simulation resources from manufacturers, such as FLIR’s Raven site planning tool. This online platform allows integrators to virtually install cameras on the proposed job site and compare image detection ranges of various cameras models.

John Distelzweig is Vice President and General Manager of FLIR’s Security segment. Request more information about the company by visiting www.securityinfowatch.com/10213696.