An Equivalent Source Method Based on Sound Pressure Differential Filter for Particle Velocity Reconstruction

During the particle velocity reconstruction, the sound energy will be dissipated and the particle velocity will be underestimated, due to the attenuation characteristic of particle velocity and the interference of measurement noise. To solve the above problem, an equivalent source method based on the sound pressure differential filter (PDF-ESM) was proposed. The method uses the sound pressure differential filter to obtain the distribution information of the sound source and focus the sound energy. Meanwhile, it uses the sparse equivalent source method to solve the precise source strength and reconstruct the particle velocity. Simulation and experiment of coherent and incoherent sound sources over 200–1600 Hz show the particle velocity results computed by PDF-ESM have smaller side lobes after the sound energy is focused and smaller reconstruction errors.