Wavelet-based beamforming for high-speed rotating acoustic source

In this paper, a novel wavelet-based beamforming approach is proposed for sensor arrays to produce acoustic images of high-speed rotating sources. First, the associated Green's function is developed based on the Morse wavelet which also accounts for the Doppler effect. Then, the beamforming operation can be conducted simply as an inversion in the time-frequency domain. Compared with the conventional Fourier-transform-based beamforming method, the proposed wavelet-based approach shows significant improvement in the real-time imaging quality and background noise suppression, which is illustrated by representative numerical simulations and experimental demonstrations. The proposed wavelet-based beamforming approach is particularly useful for the acoustic imaging in the time-frequency domain for moving sources of a high-subsonic speed and will find applications, such as audio guidance and low-noise airplane design, in robotics and aerospace industry.