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.
How Ultrasonic Sensors Work - The Technology Unveiled. One of the most versatile technologies used for object detection and level measurement is ultrasonic. An ultrasonic sensor works by using the principals of sound. The term ultrasonic means above human hearing as the sensor uses a frequency we cannot hear.