Radar, Airfield, and Weather Systems (RAWS) CDC Volume 2 Practice Test

The phase of the modulation in the conically scanned return is what the radar uses to stay on target in both azimuth and elevation. When the beam describes a cone, the echo carries a modulation at the rotation rate, and how that modulation leads or lags behind the scan reference tells you where the target sits relative to the boresight. The phase angle encodes the directional error, so the system can drive the antenna in the appropriate two-axis correction to recenter on the target. Amplitude alone would only tell you how strong the return is, not which way to steer; delay or frequency don’t provide the directional error needed for tracking.