Adaptive noise canceling for lightning electric field signals

In the measurement of lightning electric fields, both the measuring system and the electromagnetic environment inevitably introduce noise in the measured signals. When the electric field signals have significant noise levels, it is hard to recognize the weak discharge process from measured waveforms. Since the essential of the adaptive filtering is time-varying and self-adjusting, LMS adaptive filtering algorithm is chosen to reduce the presence of noise. Unlike many existing approaches, this algorithm has the advantage of requiring no a priori knowledge of the detailed properties of the noise signal. The results indicate that the algorithm can significantly improve the quality of electric field signal by suppressing the noise while leaving the signal relatively unchanged.