Sensitivity analysis of geoacoustic parameters in underwater acoustic field based on pressure sensitivity kernel

This paper investigates the sensitivity properties of the underwater acoustic field to geoacoustic parameters using the finite-frequency sensitive kernel. The sensitivity kernel of the complex pressure to the seabed sound speed variation is derived using the first-order Born approximation. The wavenumber integration method is used to simulate the sound field and obtain the amplitude and spatial distribution of the seabed sensitivity kernel at different frequency bands. The sensitivity characteristics of underwater sound field to seabed geophysical parameters are analyzed. By processing multi-channel seismic experimental data in the South Yellow Sea, the feasibility of analyzing geoacoustic parameters sensitivity characteristics using the amplitude of the pressure-sensitivity kernel is verified. The analysis method is extended to typical geoacoustic environments, and the simulation results show that in the near-field propagation conditions, the influence of geoacoustic parameters reaching deep into rock layers needs to be considered in the very low-frequency band, while in the mid-to-high-frequency bands, only the effects of various consolidation sediment layers need to be considered. For long-distance propagation, the number of seabed layers and depth to be considered can be correspondingly reduced based on the distribution of sensitivity kernels. Furthermore, the effect of simulated layered geoacoustic parameters on transmission loss and time-frequency characteristics confirms the above conclusions.