Multi-source location error and simulation study based on MUSIC algorithm

In the acoustic sensor arrays used for lightning observations, even small deviations between the actual and theoretical microphone positions may result in large relative offset errors of the actual microphone coordinates to the $x, y$, and z axes, leading to location errors, which in turn have a great impact on the accurate reproduction of lightning channel development. In this paper, we first derive the theoretical calculation method of the acoustic source location error generated by the position deviation of array elements based on the MUSIC (Multiple Signal Classification) multi-source location algorithm, and then we conduct experimental test by receiving and simulating the thunder acoustic source with a 16 -element spherical microphone array. Subsequently, the measured location results are obtained by MUSIC algorithm and the sources of errors are analyzed, and it is found that microphone position deviation is the main cause of the measured errors. Then the simulation is conducted using MATLAB and the error variation pattern between the obtained results and the measured results is consistent. The results of this paper show that, compared with the effect of array element position deviation on azimuth, it has a greater effect on the source pitch angle location, and the error in pitch angle should be modified in real measurements.