The Top Six Reasons for Using Thermal Security Cameras

‍Imagine a security camera that can peer into total darkness and display the body heat of would-be intruders like glowing white ghosts. This is the unique power of thermal cameras, and they are redefining perimeter security for businesses large and small. Thermal cameras provide enhanced detection in challenging environments, including total darkness, smoke, and bright sun glare. When equipped with analytics, thermal cameras can even classify objects as human, animal, or motorized vehicles, reducing false alarms. 

However, before we discuss the multiple applications of thermal imaging cameras, here's a quick review of the technology. 

More Than Meets the Eye

The electromagnetic spectrum is a giant "energy rainbow" that represents different types of waves that carry energy, including radio waves, microwaves, and X-rays. Visible light represents a narrow sliver of this scale. Just like our eyes, traditional security cameras rely on visible light to create images. They need a baseline amount of illumination to create an image. As a result, visible light cameras struggle in low light conditions and can be blinded by sun glare or having a light source pointed directly at them. 

Seeing "Heat" Instead

Adjacent to visible light on the electromagnetic spectrum is a range known as infrared, which is invisible to the human eye. All objects emit infrared radiation, even ice. A thermal camera uses special lenses and sensors to convert infrared energy into video images that display "heat signatures" of varying intensities. Warmer objects, such as people or animals, appear bright on screen, while cooler objects, such as the ground or surrounding buildings, appear darker.

For security applications, thermal cameras can reveal the body heat of intruders hiding in shadows, dense foliage, or total darkness, which are capabilities that visible security cameras can't match. As long as there is line of sight, thermal cameras will display the heat signature of persons or objects, even if it is just a tiny dot in the distance, and alert security professionals that something warm is out there. 

Thermal Imaging vs. IR Night Vision

It's important to clarify that thermal imaging is distinct from the "night vision" found on visible light security cameras. The terms may sound similar, but night vision involves a camera emitting a beam of light that's on the very edge of the infrared spectrum, called near-IR light. If you've ever watched the grainy green video on a ghost-hunting reality show, you've seen IR night vision in action. The disadvantage of this technology is that it still relies on reflected light and the distance the near IR beam can travel. Thermal cameras, on the other hand, strictly detect energy waves in the mid-to-far portions of the infrared spectrum. For security, thermal is the stronger detection tool because it does not depend on light, while IR night vision adds detail at close range.

Thermal Can't See Through Walls

A second misconception with thermal technology is that it's a type of "X-ray" vision that can see through walls. In fact, most materials, including water and glass, prevent the transmission of infrared radiation. This is why thermal camera lenses aren't made of glass. Instead, they're made of materials such as germanium, that allows infrared light to pass through to a special sensor. 

Thermal vs. Standard Security Cameras: How to Choose

Thermal and standard (visible light) security cameras do different jobs, so most sites get the best results from both.

• Choose thermal for detection: perimeters, fence lines, and open ground where intruders can approach in darkness, fog, smoke, or glare.
• Choose visible light for identification: faces, clothing, vehicle colors, and license plates. Thermal images show heat, not these details.
• Know the limits: thermal resolution is typically 320x240 to 640x512 pixels, well below a visible light camera, and thermal cannot see through glass, walls, or water.

For the strongest coverage, pair a thermal camera for early detection with a PTZ camera that zooms in to capture evidence.

Adding Thermal Security Cameras

So how might you incorporate thermal cameras into a surveillance system? Thermal cameras don't necessarily replace visible light security cameras but complement them. By combining thermal cameras with visible light cameras that can capture more detailed forensic evidence, a dual surveillance system will give security professionals greater confidence they can spot suspicious activity sooner. 

Here is a summary of the top six uses of thermal cameras for security applications. 

1. Perimeter Intrusion Detection 24/7

Because thermal cameras detect heat, they aren't impacted by changes in daylight. They are effective day or night. This ensures constant surveillance and coverage in scenarios where conventional visible light cameras might struggle to capture suitable images. 

2. See Hot Spots Over Long Distances

Thermal imaging cameras can detect heat signatures at extreme distances. Even if the nature of the heat source isn't immediately apparent and all we see is a distant hot spot, thermal cameras can alert security personnel of a possible intrusion before visible light cameras will reveal the danger. In this way, thermal cameras can act as a form of visual "trip wire" technology that can bring attention to potential threats as they approach.

3. Reduce False Alarms in Difficult Environmental Conditions

When objects are close enough, thermal cameras can distinguish between humans and non-threatening heat sources, such as animals or vegetation blowing in the wind. This reduces false alarms in environments with significant wildlife or rapidly changing weather conditions. For example, shifting shadows from moving clouds can fool visible security cameras into sending alerts. Thermal cameras can't see shadows, only differences in temperature. 

4. See Intruders Hiding Under Camouflage

Thermal cameras are invaluable for monitoring challenging environments, such as construction sites or remote areas. As long as there is line of sight, a thermal camera will spot a heat signature. Even if intruders hide in tall grass or thick brush thinking they are hidden, their body heat will become obvious on a thermal camera if the surrounding environment is hotter or colder within only a few degrees. 

5. Detect Extreme Temperatures Early

Hotspots in such locations as scrap yards and recycling centers can build strength before smoke or flames are visible. By then, it can be too late to intervene. Thermal cameras, on the other hand, are capable of measuring the temperature of heat signatures and sending alerts when hot spots rise above a preset threshold. This makes it possible to detect overheating equipment, electrical faults, or lithium battery fires that can threaten critical infrastructure. Facilities benefit from this dual-purpose technology that combines safety and security. By addressing potential hazards early, thermal cameras add an extra proactive layer of protection.

6. Pair Thermal with External Video Analytics

When combined with external analytics, thermal cameras can create virtual "perimeters" or "zones" such as a parking lot, fence, or property line. Depending on the security needs, certain zones can be considered safe, while others programmed as off limits. A stationary thermal camera can even "hand-off" the heat signature of an object moving across its field of view to a camera with pan/tilt/zoom (PTZ) capabilities that can continue to track the object. This greatly enhances situational awareness, especially in visually cluttered terrains.

LVT Units can be configured with thermal security cameras alongside PTZ and panoramic cameras, with short- and long-range lens options. AI detects people and vehicles and can trigger strobes, floodlights, and talk-down messages, and optional radar adds 180-degree detection with tracking. Mobile units run on solar and battery power with multi-network cellular, and video is available in the LVT app or your existing video management system. See LVT's infrared and thermal imaging cameras or explore mobile surveillance units.

Thermal Security Camera FAQs

How far can a thermal security camera see?

It depends on the lens and sensor resolution. A thermal camera can detect a heat signature long before it can show what it is, which is why LVT offers short- and long-range lens options and pairs thermal with PTZ cameras for a closer look.

Can a thermal camera identify a person?

With analytics, a thermal camera can classify a heat signature as a human, animal, or vehicle. It cannot show faces or read license plates, so pair it with a visible light camera to capture evidence.