Measuring the Spherical-harmonic Representation of a Sound Field Using a Cylindrical Array

This paper describes how to encode into a spherical-harmonic representation of a 3-D sound field using a cylindrical microphone array. The standard way to represent a sound field is to use higher order Ambisonics specified over a spherical region. If the sound field is instead measured using a cylindrical array, it is more naturally expressed in terms of cylindrical harmonics. In this paper, the transforms for conversion between cylindrical and spherical-harmonic representations are derived. Simulations then compare the performance of cylindrical and spherical array processing in estimating the spherical-harmonic coefficients of a sound field.