North Carolina Radar Operator Recertification Practice Exam

The relationship between frequency and a radar's ability to measure speed is directly linked to the Doppler effect, which describes how the frequency of waves changes in relation to an observer moving relative to the source of the waves. Specifically, when a radar signal is transmitted towards a moving object, the frequency of the returned signal shifts depending on the object's speed.

When the object is moving towards the radar, the frequency of the reflected radar signal increases, leading to a positive frequency shift. Conversely, if the object is moving away from the radar, the frequency decreases, resulting in a negative frequency shift. The magnitude of this frequency shift is proportional to the speed of the object, allowing radar systems to calculate speed effectively. Therefore, understanding that the greater the velocity, the greater the frequency shift is crucial for radar operators to accurately assess the speed of various objects. This principle is fundamental to the performance of radar systems in traffic enforcement and various forms of remote sensing.