Many ideas from science fiction films of the late 20th – early 21st century have been brought to life. I’m talking about the specific capabilities of some equipment to see the thermal field of a person and other objects. Today, a thermal imaging camera will no longer surprise a child. Let’s talk in detail about the advantages and disadvantages of thermal imaging equipment for video surveillance.
Let’s start with the basics of physics: any object with a temperature of more than absolute zero (namely, more than minus 273 degrees Celsius) emits heat. It is also called infrared or thermal radiation.
Unfortunately or fortunately, the human visual organ is not able to distinguish this type of heat release. However, this topic has haunted scientists since the Middle Ages, and the first definition of “thermal radiation” was given by the Swedish chemist Carl Scheele in 1777.
At the heart of modern thermal imaging cameras is a non-contact measuring device that reads heat indicators and determines the temperature difference between the object and environment. This is the main principle of a thermal imager in a video camera.
Visually, the heatmap differs based on temperature elevation and temperature differences. Accordingly, a higher temperature of an object gives more intense radiation, and a higher temperature difference between different objects gives a brighter and more contrasting image.
Until 10 years ago, thermal imaging cameras were used primarily for scientific purposes. Today they are already involved in various areas of human life, namely:
It is important to understand that a thermal IP camera can provide the full range of benefits. All details about network (IP) cameras can be found in the article “Network video surveillance cameras: 7 advantages and 4 disadvantages“.
Advantages of thermal video surveillance systems:
Weather conditions always affect the operation of CCTV cameras. But thermal imaging cameras are an exception: they are not interfered with by snow, rain, fog, smoke, mud. Even lush vegetation cannot trap heat radiation.
A significant plus of the thermal imager is that there is no need to illuminate the object of surveillance. In total darkness, a thermal imaging camera works exactly the same as on a clear, sunny day. Conventional cameras require special lighting, or it is recommended to install special night vision cameras, such as a wireless night vision cameras.
The accuracy of cameras is 0.1 degrees Celsius or higher.
A year ago, humanity did not even think that ubiquitous thermometry and contactlessness would be the main trends in 2020. And it is contactless technologies that will lead business and everyday life in the future.
Thermal imaging camera manufacturers claim the following average specifications:
| Surveillance aspect | Person/meters | Auto/meters |
| Detection | up to 1500 | up to 5000 |
| Recognition | up to 400 | up to 1500 |
| Accurate identification | up to 190 | up to 600 |
The imperfection of motion sensor algorithms leads to a large number of false alarms. Motion sensors in conventional cameras can be confused by a flying plastic bag, the movement of tree branches, and natural phenomena. Thermal imaging cameras are completely devoid of this drawback: for detection, they need the temperature of the object and its difference with the environment.
The Achilles’ heel of conventional cameras is ambient light. These can be sun rays, any sources of light (for example, headlights of a car), including ones deliberately directed at the camera. Cameras based on a thermal imager are not sensitive to light.
Who doesn’t want to use a camera stealthily? However, the current legislation of the Russian Federation completely excludes the secret (spy) use of equipment that contains a video camera and microphone. In addition, cameras without a thermal imager are usually supplied with additional light sources that directly indicate the location of the camera.
Thermal surveillance equipment does not require light sources, and therefore cannot be detected in the dark.
It is possible to designate certain disadvantages of thermal imaging video surveillance systems, depending on the camera model:
I want to clarify the answers to the following questions:
Thermal video equipment is a promising source of development for the IT market. And as a result of the global epidemiological situation, the process of introducing thermal imaging cameras into business has significantly accelerated. Very soon, every office center and shopping mall will be equipped with automatic thermal imagers, contactless access means (opening doors, controlling elevators). The future has already arrived.
