What NETD sensitivity really does for farm security after dark

Thermal imaging is one of the most effective ways to spot people, animals and vehicles around a farm after dark. A big part of why some devices perform better than others comes down to a spec called
NETD — a measure of how small a temperature difference the sensor can actually pick up. Lower NETD generally means better sensitivity, particularly on humid nights, in light mist, or when there’s a lot of vegetation in the way. But NETD is one piece of a bigger puzzle.