When the target echo on the radar scope is bisected by the center bearing line, the director is trained on the target, and the correct value of director train is determined.

• 当指挥仪旋转的时候，其上的雷达天线也跟着转动，当显示器上的目标回波被中央方位线（center bearing line）分为两半时，雷达天线就对准了目标，指挥仪的旋转角也就确定了。