Focusing features of surface acoustic waves on a sphere

The possibilities of geometrical description for Rayleigh's waves propagation along spherical surface are considered. The geometrical objects under consideration are the ray families of different nature: the geometrical optics rays, corresponding to the stationary points of the phase function in wave field integral presentation, and the diffraction rays, being produced by the terminal points of the line source aperture. The focusing regions and rays interference analysis is compared with the direct calculation of wave field structure