In the conical scanning technique, which property of the return signal is used to maintain track?

• A. Phase
• B. Frequency
• C. Amplitude
• D. Delay

Answer: (A)

In conical scanning, the beam is swept around the target in a circular path, and the phase of the returned echo relative to the transmitted signal carries the directional information needed to keep the radar locked on the target. When the target sits on the boresight, the phase of the echo remains stable as the beam rotates. If the target is off to one side, the rotating beam introduces a phase shift in the received signal that varies predictably with the off-center position. A phase detector uses this phase variation to generate an error signal, which the tracking loop uses to steer the beam back toward center.

Amplitude could vary with target strength or range, making it less reliable for indicating bearing, and delay primarily reflects target range rather than pointing error. Frequency isn’t the bearing cue used in this method, so phase is the property that provides the consistent, directional information needed to maintain track.