(
RAdio
Detection
And
Ranging) A method of determining the location and speed of an object. Radar works by transmitting radio waves and measuring the time it takes for them to bounce off the targeted object and return. Radar science dates back to the late 1800s.
A radar system comprises a transmitter, transmit and receive antennas, although they can be one and the same, a receiver and a processor that analyzes the objects in its path. Radar operates in a huge frequency range, from 3 MHz to 110 GHz and wavelengths from 100 meters to less than three millimeters.
Ubiquitous Today
Whereas radar was originally in the domain of the military and law enforcement, radar is commonly used in today's automobiles for safety features and full self driving. See
Doppler radar and
LIDAR.