Numerical simulation of the existence test for the diffusion function in a variable parameter medium

A model of a filter with variable parameters excited by monochromatic waves is described. Two kinds of media are considered: the Wide Sense Stationary (WSS) and WSS with the addition of no correlation termed WSSUS. The existence or not of a diffusion function may be tested by following the time evolution of the mean value of the output power or input power as a function of frequency. The theoretical properties of the impulse response of the filter are detailed together with the estimators used. The results of computations to the second order for WSS and WSSUS media are discussed together with the interaction between two frequencies in each of these media. An application to marine environments is proposed.