The New Jersey Institute of Technology's
Electronic Theses & Dissertations Project

Title:	Sequential bayesian filtering for spatial arrival time estimation
Author:	Jain, Rashi
View Online:	njit-etd2011-097 (xii, 81 pages ~ 0.7 MB pdf)
Department:	Department of Mathematical Sciences
Degree:	Doctor of Philosophy
Program:	Mathematical Sciences
Document Type:	Dissertation
Advisory Committee:	Michalopoulou, Eliza Zoi-Heleni (Committee chair) Abdi, Ali (Committee member) Bhattacharjee, Manish Chandra (Committee member) Dhar, Sunil Kumar (Committee member) Luke, Jonathan H.C. (Committee member)
Date:	2011-05
Keywords:	Particle filtering Uncertainty Regularized inversion Arrival time estimation Monte Carlo Markov chain
Availability:	Unrestricted
Abstract:	Locating and tracking a source in an ocean environment as well as estimating environmental parameters of a sound propagation medium is of utmost importance in underwater acoustics. Matched field processing is often the method of choice for the estimation of such parameters. This approach, based on full field calculations, is computationally intensive and sensitive to assumptions on the structure of the environment. As an alternative, methods that use only select features of the acoustic field for source localization and environmental inversion have been proposed. The focus here is on inversion using arrival times of identified paths within recorded time-series. After a short study of a linearization techniques employing such features and numerical issues on their implementation, we turn our attention to the need for accurate extraction of arrival times for accurate estimation. We develop a particle filtering approach that treats arrival times as "targets", dynamically modeling their "location" at arrays of spatially separated receivers. Using Monte Carlo simulations, we perform an evaluation of our method and compare it to conventional Maximum Likelihood (ML) estimation. The comparison demonstrates an advantage in using the proposed approach, which can be employed as a pre-inversion tool for minimization and quantification of uncertainty in arrival time estimation.