Abstract: Targeted at the issue of low-frequency acoustic propagation in typical shallow water environment, and based on specific example simulation, the research of the influence law of different ocean environment parameters on the acoustic signal propagation at low frequency is performed through taking fast field method (FFM) as the modeling approach and acoustic energy flow as the research subject. The results have been proved that the transmission loss of vertical particle velocity is larger than that of pressure and horizontal particle velocity. Ocean environment parameters, sound source parameters and geo acoustic parameters all have important effects on acoustic signal propagation at low frequency, and the sound velocity in ocean bottom exerts the most significant influence.

Key words: Pekeris waveguide in shallow water, low frequency acoustic signal, fast field method (FFM), acoustic propagation, acoustic energy flux