Acoustic pulse propagation in a range-dependent turbulent ocean

Abstract

When an acoustic pulse propagates a deterministic sound-speed profile, it is distorted since every frequency component experiences different extents of turbulent scattering and echo numbers. Here, the split-step method is used to simulate an acoustic pulse with a 3 kHz carrier propagating through a turbulent ocean with range-independent/dependent sound-speed profiles. It is found that (1) The ocean is a frequency-selective fading channel; (2) The received pulse profile is dependent on the received depth, sound speed distribution, fluctuation strength and scale length of turbulence in oceans; (3) The rms pulsewidth is broadened by several times of its initial value; (4) The increase in fluctuation strength or decrease in the scale length increases the rms pulsewidth; and (5) The statistical properties are similar for both the range-independent and -dependent cases in the mean square sense.