Statistical Analysis of Magnetic Fields Due to Cloud-to-Ground Lightning

초록

In this paper, the nagnetic field and B-dot wave forms due to cloud-to-ground lighnings were observed and their waveform parameters were analyzed. The frequency bandwiths of the magnetic field and B-dot waveform measurement systems were in the range of 270Hz~2.3MHz and 450Hz~2.5MHz, and their response sensitivity were 128mV/uT and 4.12mV/nT/us, respectively. the mean value of the front time of the magnetic field waveform qas 3.09us and the zero-to-zero crossing time of the B-dot waveform was 3.27us. The full width at half-maximum of the B-dot waveform describing the characteristics of transient part of magnetic field waveform was 1.25us and the average of the zero to zero-crossing times in the wave tail of magnetic fields was 59.76us, and that of the persent depth of the dip was of the order of 22.25%.