Thermal sights on weapons see heat. This has advantages in complete darkness, or in the presence of obscurants like dust storms, normal smoke, etc. because they can still pick out human and vehicle targets. Using deep infrared viewers also avoids “blooms” or whiteouts if someone flashes a bright light source like a flashlight at you. On the other hand, unless the lines on your map or lettering on that street sign have different heat values, thermal/ “deep infrared” sights aren’t going to help very much. This is why most 3rd and 4th generation night vision goggles use a combination of thermal and light intensifier technologies.
The AN/PAS-13 thermal weapons sights are used in more limited capacities, either as weapons sights or without a weapon as a sort of hand-held “night telescope.” The second generation of these sights is now being fielded, and are the subject of additional multi-billion orders from the US military.
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