What does the term 'Doppler Effect' relate to in radar systems?

The term 'Doppler Effect' in radar systems specifically refers to the change in frequency of radar waves due to the relative motion between the radar system and the target. When a target moves towards the radar, the frequency of the reflected radar waves increases, and when it moves away, the frequency decreases. This shift in frequency is crucial for determining the speed and direction of a target, as radar systems can analyze these frequency changes to compute the target's velocity. This principle is widely applied in various radar types, particularly in tracking and missile guidance systems, enhancing the overall capability and accuracy of detection and tracking functionalities.

The other options relate to different aspects of radar operation but do not define the Doppler Effect specifically. For example, the alteration of radar beam shape pertains more to beam forming or antenna characteristics, tracking multiple targets involves different signal processing techniques, and weather impacts generally focus on attenuation or scattering rather than frequency changes.