Thermal Imaging Technology for Video Surveillance Leave a comment

Honestly speaking, probably 95% of the people reading this blog post about thermal security cameras do not need it. Thermal imaging cameras are specialized security equipment that picks up the heat that radiates from the objects in a scene. For the few people who really need thermal imaging cameras, I will explain how thermal imaging works, along with the pros and cons of employing these niche surveillance cameras. With thermal cameras, the user can truly monitor an area devoid of light such as complete darkness.

How does Thermal Imaging Camera work?

Thermal imaging is a type of infrared imaging that renders infrared radiation as visible light for the creation of video images. Infrared radiation is on the electromagnetic spectrum (see image below), the frequency of electromagnetic radiation, which includes visible light, gamma rays, x-rays, ultraviolet, and microwave radiation. Since all objects emit a certain type of electromagnetic radiation called black-body radiation in relation to temperature, the thermal image camera infrared sensor will pick up this radiation to create an image. With black body radiation, the higher temperature objects will emit more infrared radiation as black body radiation.

Thermal imaging or “Thermographic” cameras use thermal imaging technology to produce images for a wide range of night-time surveillance. Thermographic cameras work in the same way as video security cameras which utilize visible light for image reproduction. Using the infrared sensor, thermal cameras can create images in the infrared spectrum of 900-14,000 nanometers (nm or µm) instead of the visible light spectrum of 450-750nm. Without relying on the ambient visible lighting, thermal imaging cameras can see in complete darkness and without the aid of any light source. The images from thermal cameras are generally in a single color channel with the difference in color due to the intensity of the temperature given off.

Thermal Imaging Applications

Thermographic cameras offer a wide range of applications such as security monitoring, firefighting, law enforcement, chemical imaging, health care, structural analysis, and paranormal investigation. The abilities of thermal imaging cameras can save hundreds of thousands of dollars from fire prevention as well as save lives through cancer testing and diagnosis.

Firefighting is one field that frequently employs thermal imaging cameras. Firefighters use handheld thermal cameras when fighting fires. The camera can help the firefighters find the origin of the fire, hot zones, and victims obscured by walls and smoke. With thermal cameras, the firefighters can quickly identify how to accurately attack a fire and reduce possible causalities. Thermographic cameras have also been used for preventative measures by identifying smoldering hot spots such as grains in a grain storage facility or fire inside a cinder railroad bed.

For the security field, the thermal imaging camera allows for superior monitoring in areas of poor lighting to total darkness. All objects emit thermal radiation and a thermal camera can use the radiation to create a visual scene in complete darkness to monitor and secure your premise. Thermographic cameras can also provide surveillance in the condition of smoke, light fog, light rain, and even light snow. Since the camera views events through the thermal spectrum, the images from day and night are nearly identical making the thermal imaging camera a true 24-hour surveillance device.

Night Vision Technology

Most security cameras use CCD/CMOS image sensors to reproduce an image for CCTV use at very low light levels. The problem with CCTV cameras is that, even at low levels, the cameras require some sort of light to create an image. So, the security industry uses various night vision technologies for monitoring in difficult lighting conditions.

Thermal imaging is one of the few mainstream night vision technologies out in the security industry right now. The other main night vision technology is infrared. Infrared provides the camera with enough light to capture an image. Both technologies offer advantages and disadvantages.

Pros and Cons of Thermal Security Cameras

The major drawback of thermal imaging is the cost of the products when compared to infrared. You can find infrared cameras under $100 while the least expensive thermal cameras start at around $3,000. Resolution is another issue facing thermal imaging as most thermographic cameras offer resolutions of 320×240 or 640×480 pixels. While infrared cameras can provide resolutions up to 700 TV lines (976×508 pixels). One more notable con for thermal imaging cameras is that it can not pick up the thermal radiation through glass.

As for the advantage of choosing thermal imaging technology, thermal cameras can work in absolute darkness and out to a greater range. Infrared cameras must have a light source, usually infrared LEDs or LED IR illuminators, to create an image. With the IR LEDs showing, an infrared camera would clearly pinpoint any intruder of its location if the camera was meant to be discreet. Also, the LED illumination can go up to a range of 100 feet and thus limiting the viewing area of the camera to around that same distance. Another hindrance to the infrared camera is the presence of poor weather conditions like fog or light rain and obstructions like smoke or scenery. In those situations, the infrared camera would be creating images from the light reflecting off the fog, rain, or obstruction defeating the purpose of security monitoring. Since thermal imaging does not rely on visible light, you will get a more accurate depiction of what you are monitoring.

Thermal Imaging when it comes to video surveillance can come in quite handy or even be necessary to some in certain industries. That said, it’s not for everybody. If you have specific questions about thermal imaging security cameras, feel free to call us or even leave a comment below – 1-877-926-2288