One representation of the solution of a wave equation

The E field which is the solution of the wave equation for an inhomogeneous medium is represented in the form of a new series. Every term of this series, starting with the second, is expressed through E sub 0 and G fields. The first term of the E sub 0 series is a wave passing through an inhomogeneous layer, and G is the sum of the field reflected from the inhomogeneous layer and the source field. The E sub 0 and G fields are defined by integrodifferential equations which are governed by the causality principle. The obtained series can be used in problems of wave propagation in randomly inhomogeneous media, where the use of causality equations makes it possible to simplify the computation of the statistical characteristics of the field.