利用低频磁场天线遥感测量人工引雷中的初始连续电流

Application of Low-frequency Magnetic Sensor for Remote Measurement of the Initial Continuous Current in Rocket-triggering Lightning

2014年夏季的山东人工引雷实验中,我们利用高灵敏度宽频段磁场天线在距引雷点78 m的距离上开展了对人工引雷初始连续电流过程的遥感测量。通过分析实验期间5次人工引雷的综合观测数据,发现磁场遥感方法对人工引雷中特有的初始连续电流有很好的反演效果。通过对78 m距离上获得的磁场测量信号进行积分处理,能够有效地抑制测量过程中白噪声的影响,从而反演得到初始连续电流的低噪声时变波形。该方法为获取空中引雷实验中的初始连续电流波形提供了一种解决方案,同时也可用于反演近距离自然闪电中地闪回击中的长连续电流的时变波形。

We present a new method to remotely measure the initial continuous current in classical rocket-triggering lightning using a compact low-frequency magnetic sensor deployed at 78-m distance from the channel base. The current waveform retrieved from the numerical integration of close magnetic signals shows very well the general feature and all the slow variations（such as the initial continuous current pulse） embedded in the channel base current measured with ashunt. Compared with the shunt measurement, the new method has the advantage of significantly reduced noise. This method can be applied to remotely probe the initial continuous current in upward lightning from high objects and altitude-triggering lightning, as well as long continuing current in natural cloud-to-ground lightning at a close range.