Crows are members of the Corvidae family, which also includes ravens, magpies, and blue jays. Loud, rambunctious, and very intelligent, crows are most often associated with a long history of fear and loathing. They are considered pests by farmers trying to protect their crops and seedlings. Many people fear them simply because of their black feathers, which are often associating them with death.
Modern Infrared Search and Track systems can search, track and target an enemy aircraft while having a better ability to differentiate discreet aircraft in formations and intermediate ranges than many traditional fighter radar systems fielded today.
The sensor in a motion detector is actually split. in two halves. The reason for that is that we are looking to detect motion (change) not. average IR levels. The two halves are wired up so that they cancel each other out. If one. half sees more or less IR radiation than the other, the output will swing high or low.