1.Thermal imaging Introduction
Thermal imaging is the technique of using the heat given off by an object to produce an image of it or to locate it
All objects have a certain temperature and emit waves of energy called infrared radiation. Hot objects emit more energy than cold objects. A thermal imager translates these energy waves into a viewable image, which shows a “heat picture” of a scene. On the screen of a thermal imager set to white-hot, hotter objects show as white, cooler objects show as black, and objects in between these temperatures are displayed in shades of gray.
Some thermal cameras, however, add color to images to help users identify objects at different temperatures
First developed for military purposes in the late 1950s and 1960s
In recent times it is being used in firefighting, law enforcement, industrial applications, security, transportation, medical and many other industries.
Works in environments without any ambient light and can penetrate obscurants such as smoke, fog and haze.
2. TYPES OF THERMAL IMAGING CAMERAS
1）COOLED THERMAL IMAGER
Cooled detectors are typically contained in a vacuum-sealed case and cryogenically cooled
Cooling is necessary for the operation of the semiconductor materials used else they would be blinded by their own radiation
Cooled infrared cameras provide superior image quality
Bulky and expensive to produce and run
Cooling is power-hungry and time-consuming hence the camera needs time to cool down before it can begin working again
2）UNCOOLED THERMAL IMAGER
Un-cooled detectors use a sensor operating at ambient temperature, or a sensor stabilized at room temperature using control elements
Resolution and image quality tend to be lower than cooled detectors
Smaller and less costly to produce and run
Fast operation and consumes less power
Cooled VS uncooled thermal comparison
- THERMAL IMAGING APPLICATIONS
1) THERMAL IMAGING IN BORDER SECURITY
Due to their ability to detect man sized targets at extremely long distances in total darkness and in extreme weather conditions thermal imaging cameras are extremely suited for border surveillance.
Generally, cooled cameras are used in border security applications as they provide a longer range performance than uncooled detector.
If the terrain is e.g. mountainous and does not permit seeing over a distance of 20 kilometers, uncooled thermal imaging cameras can be used for border security as well.
Thermal imaging cameras can be integrated with radar systems.
2)THERMAL IMAGING IN SECURITY AND LAW ENFORCEMENT
With a thermal imager, an officer can stop and scan the property at a distance, identifying any person present there.
Perimeter surveillance is another application in which thermal imaging can be used to dramatically improve results and reduce the time committed to a particular operation.
Thermal imaging cameras are also used in search and rescue operations as officers may be able to search up to 6km in any direction.