Infrared (IR) imaging can maintain surveillance coverage under which condition?

• A. Night time
• B. Bright daylight
• C. Clear skies
• D. Heavy rain

Answer: (A)

Infrared imaging detects heat emitted by objects, not relying on visible light. That means it can keep surveillance running when lighting is poor, especially at night, because warm bodies like people or vehicles stand out against cooler surroundings even without daylight. In bright daylight, infrared can still work, but the sun’s heat can reduce contrast and make some details harder to distinguish. Heavy rain attenuates infrared signals and degrades image quality, so it’s less reliable in such conditions. Clear skies don’t inherently improve infrared performance the way complete darkness does. So night time is the condition where infrared imaging most reliably maintains surveillance coverage.