Correction of near-field acoustic measurements made with arbitrary measuring transducers

This paper concerns the basic acoustics problem of the coupling between the near-field acoustic pressure field radiated by a source and an arbitrary measuring transducer such as a microphone or hydrophone. It is shown that the far-field of a source can be determined independently of the phase and amplitude directional characteristics of the measuring transducer provided that the far-field response of the measuring transducer is known. Solutions to the problem are obtained by an application of Green´s theorem to the modal expansions of the acoustic pressure field in rectangular, cylindrical, and spherical coordinate systems.