ACOUSTIC PULSE-PROPAGATION IN A FLUCTUATING OCEAN WITH RANGE-DEPENDENT SOUND-SPEED PROFILE

When an acoustic pulse propagates in a randomly fluctuating ocean with a deterministic sound-speed profile, it is distorted since every freq uency component experiences different extents of scattering from the r andom inhomogeneity and echo numbers. Here, the split-step method is u sed to simulate an acoustic pulse with a 3-kHz carrier propagating thr ough a turbulent ocean with range-independent/-dependent sound-speed p rofiles. It is found that (1) the ocean is a frequency-selective fadin g channel; (2) the received pulse profile is dependent on the received depth, sound-speed distribution, fluctuation strength, and scale leng th of turbulence in oceans; (3) the rms pulsewidth is broadened by sev eral times its initial value as a consequence of pulse echoes and puls e wandering of every pulse realization of the ensemble; (4) the rms pu lsewidth is increased when the fluctuation strength increases or the s cale length decreases; and (5) the statistical properties of the propa gating pulse are similar for both the range-independent and -dependent cases in the mean square sense. (C) 1996 Acoustical Society of Americ a.