Reference-wave solution for the two-frequency coherence function in random media

High data rate communication systems at millimeter and optical frequencies used for both mobile and satellite links may be influenced by pulse spreading due to scattering by turbulent inhomogeneities and hydrometeors in the troposphere and by the electron concentration in the ionosphere. Theoretical analysis of pulsed signal propagation is usually based on the analysis of the two-frequency mutual coherence function. In this work we propose a new reference wave method which enables us to present an analytic solution for the equation of the two-frequency mutual coherence function. It is shown that when approximating the transverse structure function of the medium by a quadratic form, the solution reduces to the exact result derived previously. Propagation of plane and spherical waves in the more general types of media is considered.