A multi-step method of geo-acoustic inversion by ambient noise

Seabed parameters sensitivity to the vertical spatial characteristics of ocean ambient noise field is analyzed.A multi-step method of geo-acoustic inversion is proposed based on the characteristics that seabed density is insensitive to the vertical directionality of ambient noise below the critical angle and relatively sensitive to the seabed reflection loss at steeper angles.Seabed sound speed and attenuation are inverted by the vertical array response of ambient noise below the critical angle first,and then density is inverted by the part at steeper angles.The simulations and experiment data processing are performed to validate this method.The results was demonstrated that the multi-step method improves the inversion efiBciency and accuracy of seabed density because of the enforced focus on the sensitive parts of matching physical quantities and it is feasible.