Fine Three‐Dimensional VHF Lightning Mapping Using Waveform Cross‐Correlation TOA Method

Abstract

Abstract Waveform cross‐correlation approach was first applied to three‐dimensional very high frequency (VHF) lightning mapping. A Hilbert transform of the original waveform and a three‐step cross‐correlation parsing process were employed to compute the time differences with a small 10‐μs time window for the final time‐of‐arrival (TOA) positioning. The lightning channel continuity was significantly improved, and its fine structure, including the K process, was clearly distinguished with speeds of up to 1.1 × 107 m/s. The two overlapped K processes indicate the high location accuracy of the time‐of‐arrival, based on the waveform correlation method. The median (mean) values of the positioning precision with the proposed method were evaluated by duplicate located sources and estimated as σx = 20 m (26 m), σy = 19 m (28 m), and σz = 54 m (67 m).