Enhanced Doa Estimation for Lightning Sources Using Music and Coherent Signal Subspace Method

The MUSIC algorithm has been widely utilized in fields such as communications and radar and has recently garnered attention in lightning source localization. However, the traditional MUSIC algorithm faces two key limitations when applied to lightning localization: it is primarily designed for narrowband signals, rendering it less effective for processing the wideband signals characteristic of lightning radiations, and it struggles to accurately estimate multiple simultaneous radiation sources, a common occurrence in the complex and transient discharge processes of lightning. To overcome these challenges, this study introduces an enhanced MUSIC-CSSM fusion algorithm tailored specifically for lightning radiation source localization by integrating the coherent signal subspace method (CSSM) with a uniform L-shaped array, effectively handling the broadband characteristics of lightning signals and improving multi-source resolution. Simulation results demonstrate precise localization for single and dual radiation sources, while field experiments at a lightning-triggering base validate the proposed method's superior performance, achieving a 60 % improvement in multi-source separation compared to the traditional MUSIC algorithm and successfully reconstructing lightning discharge channels. Future work will primarily focus on observing additional lightning cases and further optimizing the computational efficiency of the algorithm.