SOUND PROPAGATION IN RANDOM MEDIA. Backscattering correction to the multiple forward scattering theory

The Parabolic Equation Method ( P E M ) is the commonly used method to deal with wave propagation in random media. This method basically requires the small ratio of wave length to correlation length (small angle scattering). Recently, de Wolf/2/ and Rino/3/ extended the PEM by including the backscattered wave, retaining the small angle scattering. In his dissertation, GroBe/4/ generalized the PEhQ to the case of forward wide angle scattering. In this paper, a further generalization leads to a solution for the first moment of the scalar Helmholtz equation without any restriction concerning the scattering angles.