Night Vision and Thermal Systems

Thermal Imaging Basics

According to the Law of Black Body Radiation, anything that has a temperature above zero emits an infrared radiation which produces images called thermograms. Any image of the radiation emitted in the infrared range of around 9,000 to 14,000 nanometers in contrast to common cameras with a range of 450 to 750 nanometer (according to the electromagnetic spectrum) is distinguishable and can be perceived through thermal imaging cameras. Therefore, through thermal videography, one’s sight is extended and heightened in the sense that he is able to see his surroundings sans the daylight illumination or direct visibility, like seeing through darkness and concretes.

Thermal imaging cameras have to general classification, characteristically: those with cooled infrared image detectors installed in the unit, while others have the uncooled infrared image detectors.

Most cooled detectors function at around 60 to 100 Kelvin range in comparison to the usual operating temperatures of 4 Kelvin to the normal room temperature. Therefore, without the cooling feature, a typical thermal imaging device will be blinded or will only see everything heated up due to their infrared radiation emission. Cooled thermal imaging cameras grants better image quality compared to uncooled versions. With this added feature, the camera would experience delays on cooling down before it could be used. Further, the device would also require extra energy and the design suffers from being bulky, thus, making it more expensive that the uncooled versions.

On the other hand, uncooled thermal imaging cameras function well in ambient temperature environment from a normal room temperature to around 4 Kelvin. An increase in temperature causes unavoidable noise on the image quality which only requires stabilization in order to reduce the distortion. Given that it is smaller and less expensive, the resolution and image quality is compromised.

Infrared imaging (picture by Passivhaus Institut)

Infrared imaging (picture by Passivhaus Institut)

This technology was originally invented to be utilized by military personnel during the Korean war circa 1950-53, though; it was slowly applied to other line of work such as law enforcement, further military operations, search and rescue, medical testing diagnosis, firefighting among many others.

In law enforcement, tactical operations and entry rely greatly on this technology because they need better assurance that their work plan is close enough to the success that they desire for the operation. This is also vital on fugitive chase and apprehension

Firefighters and field medics also depend on the capability of the thermal imaging camera to locate first the victim in a pile of debris before taking the risk of letting somebody proceed with a wild goose chase in between large rocks. They are also able to determine a base of a fire which saved them from making the job risky than it used to be. Search and rescue made good use of this technology to locate missing subjects and saved them time from doing random guesses.

Medical personnel, among the many professions, also benefited from the breakthrough by making energy audit and body heat loss determination of patients. They were already able to determine at an earlier stage the necessary treatments that the patient have according to the data that the thermal imaging camera gathered.

Thermal imaging camera has the upside against the night vision technology in the sense that the former can still function properly with the least to no available light in the environment of the subject; whereas, the night vision needs an ample amount of light source to enable it to get a visual on its subject and its environment. This is one major difference of the two devices used on almost the same purpose.

Categorised as: Thermal Systems

Comments are closed.