Radar is an abbreviation of Radio Detection And Ranging.

For radar to function, the radar dish or antenna transmits pulses of radio waves or microwaves which bounce off any object in their path. The object returns a tiny part of the wave’s energy to a dish or antenna which is usually located at the same site as the transmitter. This signal is then translated electronically to indicate physical properties of the reflected object like speed, range, altitude, and direction.

Radar was secretly developed by several nations before and during World War II. The term RADAR was coined in 1941 by the United States Navy and has since entered English and other languages as the common noun radar, losing all capitalization.

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