Thermal imagers can be extremely useful in fire-fighting operations. Their ability to see through smoke and debris allows fire-fighters to find people who have passed out and those fighting for survival but are too afraid to come out from hiding. Thermal imagers can also tell a fire-fighter if a door is hot and possibly contains a fierce blaze on the other side.
Thermal imagers designed for fire-fighting missions are designed to operate in very rough and tough environmental conditions.
Thermal imagers are extensively used by law enforcement agencies and armed forces for a variety of applications in navigation, detection and targeting. These allow them to detect potential threats without exposing their location to the adversary. State-of-the-art thermal imaging rifle scopes have become rugged enough to withstand the abuse of recoil, making these extremely popular with the armed forces.
While thermal imagers are incredibly effective when it comes to detecting human beings or animals, discrimination between a friend and a foe may be a challenge. This may be an issue in life-and-death situations.
Thermal imaging cameras are one of the most effective tools for surveillance because these work equally well during the day and at night. Regular CCTV cameras are limited by their need for light, and night vision devices do not function during the day. The chance to see through smoke and fog also gives thermal a leg up on other surveillance techniques.
Fig. 8 shows a thermal imaging sensor designed for border and coastal surveillance array. It offers continuous zoom from 25° to 2°, and a long-range detection capability. The sensor can detect a human being-sized target from more than 15 kilometres away.
State-of-the-art sensors intended for surveillance, target detection and tracking applications employ multi-sensor configurations, often combining a visible spectrum sensor with an IR sensor. Final image in this case is the result of fusion of imaging data from two sensors.
To be continued…
Dr Anil Kumar Maini was formerly outstanding scientist and director at Laser Science and Technology Centre (DRDO)
Nakul Maini is post graduate in optical engineering from University of Bristol (UK), currently working as senior engineer (product development) at Tek Xplore, New Delhi