The velocity of stochastic variability in the method of complete correlation analysis

If the wave properties of the medium of propagation are known a priori, it is possible to construct the space-time correlation function of random homogeneous stationary wave fields, propagating in a given unbounded medium in the absence of drift and extraneous wave sources; this can be done by measuring the temporal autocorrelation function of the field at one point of space. If the dispersion equation of the medium is unknown or if there is a drift of the medium, the parameters of the wave field can be estimated by complete correlation analysis with narrow-band filtering of the temporal versions of the field, obtained at two, three, or four spaced receiving points (depending on the dimensionality of the wave-propagation space). Here, the velocity of stochastic variability is proportional to the phase velocity of the waves.