Cooled thermal refers to a thermal camera that utilizes an integrated cryogenic cooler. Since thermal cameras work by detecting radiated heat, any extra heat in the camera increases unwanted background noise in the image. The cryocooler chills the thermal image core to temperatures as low as -196°C (-321°F), which increases the sensitivity and accuracy of the thermal image, dramatically increasing both range and performance.
Most cooled thermal cameras are InSb and have to be cooled to 77° Kelvin (-196°C or -321°F). These coolers need to run continuously, requiring replacement roughly every 8,000 to 10,000 hours of operation. Infiniti has options that run at a higher temperature, such as our X-Hot sensor. Since this sensor doesn’t need to be cooled as low, the coolers have longer lifetimes which reduce the cost of ownership. Of course all cooled thermal cameras will require maintenance at some point; even if the cooler itself does not fail, sometimes the seal and dewar assembly can, which is why cooled thermal cameras have higher maintenance costs compared to uncooled thermal or visible cameras.
Since cooled thermal IR cameras are so sensitive to tiny temperature differences, they can spot a target with only a few degrees temperature difference from its background. They work on mid-wave infrared wavelengths (MWIR) and typically use wavelengths of 3-5µm (3000nm to 5000nm). The combination of the cooled image core and the ability to work on the MWIR spectrum, when used with Infiniti’s long-range optics, means ultra-long range detection capabilities (up to 20 miles or 30km) even if there is only a few degrees temperature variance between the target and background.
While cooled cameras are a significant investment and are considerably more expensive then uncooled, their superior range and performance allows them to deliver results that uncooled thermal cameras simply can’t achieve, making them a vital solution for certain applications such as coastal surveillance, and a cost-effective solution in applications such as border security, where the longer range of cooled thermal can cover the same perimeter length of up to 8 individual uncooled thermal cameras.
For more information about thermal infrared imaging for night vision and surveillance see our Thermal Imaging Explained page.