Case Details
At night, for well-known reasons, visible-light devices fail to function properly. Artificial lighting can be used as an alternative, but this approach is likely to expose the target. Meanwhile, low-light night vision devices also operate in the visible-light spectrum and thus still rely on external light sources for illumination. In contrast, infrared thermal imagers passively detect the infrared thermal radiation emitted by the targets themselves. They can work reliably both day and night without revealing their own position.
Similarly, in severe weather such as rain and fog, visible light—with its short wavelength—has poor obstacle-penetrating capability, resulting in unsatisfactory observation performance. However, infrared radiation has a longer wavelength; thermal imagers operating specifically in the 8–14 μm band exhibit strong penetration through rain and fog, enabling stable target detection in such conditions.
Therefore, infrared thermal imaging surveillance equipment is well-suited for monitoring various targets (e.g., personnel and vehicles) during nighttime and severe weather conditions.
