Thermal Camera

Abstract

Thermal network cameras create images based on the principles of infrared (IR) radiation. All objects and organisms generate some amount of heat. Heat is a form of light that is invisible to the eye and is also known as thermal IR radiation. The thermal camera serves as a heat sensor that detects temperature diffe ences between objects and the scene itself. Rather than a picture of light, the thermal image is a visual capture of heat. The more heat an object emits, the brighter it appears in a thermal image. Thermal images give the most information when there are significant temperature diffe ences in a scene. Images are generally produced in grayscale where dark areas indicate colder temperatures and light areas warmer ones. Color palettes can be added to enhance diffe ent shades in the image. Thermal cameras can detect people, objects, and incidents in low-light environments, complete darkness, or other challenging conditions such as smoke-filled and dusty environments. Thermal imaging has proved to be a lifesaver in emergency situations. See Figure 5.1 for illustrations of thermal camera detection. Because thermal imaging does not provide sufficient information for identification, its primary use is to detect irregularities and suspicious activities. Thermal cameras quickly and accurately detect any incidents occurring in their fi ld of view. They are robust and cannot be blinded by strong lights or put out of order using laser pointers. These qualities make them a great choice for first line of protection. Upon detecting an incident, they can immediately trigger further action, dramatically enhancing the eff ctiveness of a surveillance system. Thermal cameras are perfect for perimeter or area protection. They are a powerful and cost-eff ctive alternative to radio-frequency intruder detection, fences, and floodlights. Since thermal cameras do not need ambient light to produce images, they provide discreet surveillance in complete darkness. And in situations where some light is still needed for identification purposes, they can reduce the need for excess illumination. Thermal cameras can also improve security in off-limit spaces, for example, in transportation areas such as tunnels, railway tracks, and bridges. Indoor uses include building security and emergency management. Thermal cameras can detect humans inside a building after business hours or in emergency situations, for example, when rooms fill up with smoke. High-security buildings, nuclear power plants, correctional facilities, airports, pipelines, and sensitive sections of railways also benefit from thermal camera surveillance. Dual cameras offer a combination of conventional and thermal camera technology. They can provide a very wide range of detection and surveillance and are ideal for mission-critical applications where 24-hour monitoring is required (see Figure 5.2).