Study of Multirate Sampled Acquisition of Lightning Current Waveform Based on Short-Time Fourier Transform

In the field of lightning current waveform acquisition, since the lightning stroke signal contains continuous current whose change is relatively flat, sampling with a fixed frequency is a waste of memory resources, and may even increase system design difficulty and cost. The multirate sampled method has been proposed to acquire lightning current waveforms based on the short-time Fourier transform (STFT) to counter this problem and cubic Hermite interpolation has been used to optimize sampled data. The results of simulation and lightning experiments have shown that the multirate sampled method reduces memory resource consumption by at least 70% and ensures high accuracy. The feasibility and effectiveness of the multirate sampled method have also been confirmed.