A significant step beyond the introduction of the continuum counterpart of time averaging over a time window of the output of a phase Doppler particle anemometry on a dense suspension of particles has been carried out. This has been accomplished by introducing short time shifts to retain the characteristics of high frequency fluctuations of averaged properties. This preservation of the high frequency components of fluctuations has made it possible to determine the correlations, power spectrum, and diffusivity of the particle phase, important parameters in the design of various transport processes. Illustrative details are presented on local density, velocity, and particle size distribution. The latter suggests caution in probing for a representative mass flux of particles in pipe flow.