Spherical Bessel and Hankel functions
spherical Bessel functions for interior fields
For the interior fields, the components are real-valued, therefore the animated real-part has fixed zero-crossings.![spherical Bessel functions for interior fields spherical Bessel functions for interior fields](https://iaem.at/Members/zotter/spherical_soundfield/radial_incoming_anim.gif)
spherical Hankel functions for exterior fields
For exterior fields, zero-crossings must travel outwards and the magnitude must decay with 1/r after some distance.![spherical Hankel functions for radiation spherical Hankel functions for radiation](https://iaem.at/Members/zotter/spherical_soundfield/radial_outgoing_anim.gif)