Resolution enhanced statistically optimal cylindrical near-field acoustic holography based on equivalent source method

For the sound field reconstruction of large cylindrical surfaces, statistically optimal cylindrical near-field acoustic holography (SOCNAH) has high reconstruction accuracy but low resolution. To solve this problem, resolution enhanced SOCNAH (RE-SOCNAH) based on equivalent source method (ESM) is proposed. Firstly, near-field measurements are used to acquire the complex sound pressures on the holographic surface. Secondly, with the sound field on all measurement points as boundary conditions, single-layer potential ESM is used to reconstruct the sound pressure on corresponding interpolation points. Finally, with the sound pressure on all holographic points after interpolation, SOCNAH is used to reconstruct the sound pressure on the large cylindrical surface. Furthermore, arrangement of equivalent sources and performance of RE-SOCNAH are studied according to typical numerical and experimental studies on a cylindrical test bed. Generally, this paper provides an accurate and RE-NAH method for large cylindrical surfaces, which can provide significant evidences for noise monitoring and control.