Passive inversion of sound speed profile based on normal mode extraction of monochromatic signals

Abstract Sound speed is an important parameter in underwater acoustics, and the inversion of sound speed profiles (SSPs) has been a focus of numerous studies. In this paper, we propose a mode extraction-based SSP inversion (ME-SSPI) method. This method utilizes the relationship between SSP, mode parameters, and source velocity to simultaneously estimate SSP and source velocity from a monochromatic signal. Mode parameters (e.g., modal depth functions and horizontal wavenumbers) are extracted using acoustic data received by a vertical linear array. SSP estimation results are further optimized by a denoising autoencoder network. The effectiveness of the ME-SSPI method is verified by simulations.