 The radar mile is the time it takes for a radar pulse to travel one nautical mile, reflect off a target, and return to the radar antenna.Since a nautical mile is defined as 1,852 m, then dividing this distance by the speed of light (299,792,458 m/s), and then multiplying the result by 2 yields a result of 12.36 μs in duration.Another form of distance measuring radar is based on frequency modulation.