What audio cue helps in identifying target speed while using RADAR?

The identification of target speed while using RADAR is primarily aided by Doppler audio. This type of audio cue is generated by the Doppler effect, which is the change in frequency or wavelength of a wave in relation to an observer moving relative to the source of the wave. When a RADAR system detects a moving target, it calculates the speed of the target and produces a corresponding audio tone that changes in pitch according to the speed detected.

As a target approaches, the pitch of the audio increases, and as it moves away, the pitch decreases. This immediate feedback allows officers to quickly assess the speed of the vehicle without needing to visually confirm it through the RADAR display. Therefore, Doppler audio serves as a critical tool in enhancing situational awareness and supporting accurate speed enforcement.

In contrast, voice announcements may provide general information but are not directly tied to speed measurement. Sirens are used primarily for alerting purposes rather than directly indicating speed. While a steady beep may signal the operation of the system or signify a specific condition, it does not convey the nuanced information regarding target speed that Doppler audio provides. Thus, it is clear why Doppler audio is the correct answer in the context of identifying target speed with RADAR.