title: Probabilistic two-dimensional water-column and seabed inversion with self-adapting parameterizations.
abstract: This paper develops a probabilistic two-dimensional (2D) inversion for geoacoustic seabed and water-column parameters in a strongly range-dependent environment. Range-dependent environments in shelf and shelf-break regions are of increasing importance to the acoustical-oceanography community, and recent advances in nonlinear inverse theory and sampling methods are applied here for efficient probabilistic range-dependent inversion. The 2D seabed and water column are parameterized using highly efficient, self-adapting irregular grids which intrinsically match the local resolving power of the data and provide parsimonious solutions requiring few parameters to capture complex environments. The self-adapting parameterization is achieved by implementing the irregular grid as a trans-dimensional hierarchical Bayesian model with an unknown number of nodes which is sampled with the Metropolis-Hastings-Green algorithm. To improve sampling, population Monte Carlo is applied with a large number of interacting parallel Markov chains with adaptive proposal distributions. The inversion is applied to simulated data for a vertical-line array and several source locations to several kilometers range. Complex acoustic-pressure fields are computed using a parabolic equation model and results are considered in terms of 2D ensemble parameter estimates and credibility intervals.
authors: School of Earth and Ocean Sciences, University of Victoria, Victoria, British Columbia V8W 3P6, Canada. jand@uvic.ca
authors: Jan
authors: J
authors: Dettmer
authors: Stan E
authors: SE
authors: Dosso
mesh_terms: D000162:Acoustics; D000465:Algorithms; D001499:Bayes Theorem; D003198:Computer Simulation; D019015:Geologic Sediments; D008390:Markov Chains; D015233:Models, Statistical; D009010:Monte Carlo Method; D009038:Motion; D017711:Nonlinear Dynamics; D009716:Numerical Analysis, Computer-Assisted; D009792:Oceans and Seas; D011312:Pressure; D012815:Signal Processing, Computer-Assisted; D013016:Sound; D013018:Sound Spectrography; D013997:Time Factors; D014867:Water
chemical_list: D014867:Water