1. 雷达;无线电定位装置
    Radar is a way of discovering the position or speed of objects such as aircraft or ships when they cannot be seen, by using radio signals.

    e.g. Pilots complained that the radars in the Mirages malfunctioned during conditions of high humidity...
           飞行员抱怨说在高湿度条件下，“幻影”战斗机上的雷达出现了故障。
    e.g. The aircraft was on a flight from Milan when it disappeared from radar screens.
           飞机是在从米兰出发的飞行途中从雷达屏上消失的。