Study on the Impact of the Doppler Effect on the Localization and Identification of Moving Lightning Radiation Sources

The Doppler effect induced by the motion of lightning radiation sources, referring to electromagnetic radiation sources associated with lightning discharges (especially in the very-high-frequency (VHF) band), affects the propagation and reception of electromagnetic signals, thereby reducing the accuracy of lightning radiation source localization and identification. In this article, to address this issue, based on the Minimum Variance Distortionless Response (MVDR) beamforming algorithm and by introducing the Doppler effect into the localization and identification theory of stationary radiation sources, simulations are performed to comparatively analyze the localization and identification features of both dual-stationary and dual-moving lightning radiation sources. Then, the impact of Doppler shifts on the localization performance of moving lightning radiation sources is investigated. The results show that circular planar array localization accuracy is closely linked to the spatial resolution of the system. The higher the cloud height, the greater the elevation angle, and the higher the spatial resolution. Furthermore, the impact of the Doppler effect on localization accuracy intensifies with higher radiation source frequencies and larger frequency differences between dual radiation sources, leading to greater localization deviations, particularly for high-frequency VHF emissions. This study reveals the mechanism of how the Doppler effect affects moving lightning radiation source localization, providing theoretical support for subsequent field experimental observations and fine-structure research on lightning channel development.