An approach to characterising operator spectra using a ray-dynamical phase space, originating from treatments of quantum mechanics, is adapted to calculate degrees of freedom and channel capacities of wireless communication between surfaces. The method is grounded on propagation of correlation functions and exploits the outputs of Eulerian raytracing algorithms. It presents results using a signal-to-noise ratio expressed as a function of phase space coordinates, resolving it in terms of direction as well as position. The ability of the phase-space representation to capture the spatial-angular dynamics of propagation makes the methodology suitable for advanced studies of electromagnetic signal and information theory. Examples are offered for flat as well as curved surfaces, communicating in free-space and in confined propagation environments.
