The multipath structures of pulsed propagation and fluctuations of the thermocline in shallow water
Renhe Zhang
State Key Laboratory of Acoustics Institute of Acoustics Academia Sinica
There are strong fluctuations of thermocline and internal wave in summer in the Yellow Sea. Beside the direct measurement, the multipath structures of the pulsed signals can also reflect the variation of thermocline. The data of the 96's and 97's experiments in the Yellow Sea show strong relationship between the thermocline fluctuation and multipath structures in the acoustic propagation. Chirp Signals and M-sequence Signals were used in these experiments. Pulse compression and some other techniques of DSP were also introduced. The variation with the time of the multipath structures were observed. Computed multipath structures from the thermocline fluctuation by Bind Displacement and Ray Mode (BDRM) theory were given out. Strong coincidence between the computed results and experiment exists. This shows that the multipath structures in the acoustic propagation can be used to invert the variation of thermocline and internal wave.