thermalimaging

Thermal imaging, also called infrared thermography, is the practice of producing images from infrared radiation emitted by objects. All objects with temperatures above absolute zero emit infrared energy. Thermal cameras detect this radiation and convert it into a visible image, where colors or grayscale correspond to surface temperatures. Unlike visible-light cameras, thermal imagers are largely independent of ambient light and can operate in darkness and through smoke or poor visibility, though performance depends on emissivity and atmospheric conditions.

Most contemporary thermal cameras use uncooled microbolometer detectors in the long-wave infrared (LWIR) band, roughly 8–14 micrometres, though shorter-wave infrared bands are used in specialized systems. Detectors convert infrared radiation into electrical signals, which are processed to form a thermogram, often with a color map or grayscale indicating temperature.

Emissivity varies by material, so apparent temperature can differ from true temperature; reflective or shiny surfaces can mislead measurements. Calibration and scene knowledge are important for accurate thermography.

Applications include building diagnostics (leaks, insulation), electrical and mechanical maintenance (overheating components), medical thermography, firefighting, surveillance, search and rescue, and automotive night vision.

Limitations include lower spatial resolution compared with visible cameras, dependence on emissivity, atmospheric absorption at some bands, and cost of higher-end systems.