INFLUENCE OF THERMAL TURBULENCE ON ATMOSP HERIC ACOUSTIC-WAVE PROPAGATION IN THE PRESENCE OF NEGATIVE VELOCITY-GRADIENTS

A numerical technique for simulating the acoustic wave propagation thr ough a turbulent atmosphere is introduced. We first generate a random homogeneous and isotropic medium by creating N independent realization s in terms of discrete Fourier modes. Then, for each realization, we s olve a parabolic equation using a Split step Pade algorithm. Finally, we calculate the mean intensity of the acoustic field and its phase an d amplitude fluctuations. Our numerical results are compared with outd oor measurements.