directional radio beacon

例句：

1. 1. The directional radio beacon helps pilots find their way in the fog.
   这个定向无线电信标在雾中帮助飞行员找到方向。
2. 2. The new directional radio beacon system has greatly improved navigation accuracy.
   新的定向无线电信标系统大大提高了导航的准确性。
3. 3. The military uses directional radio beacons to communicate with each other in battlefield situations.
   军队使用定向无线电信标在战场情况下互相通信。