Matched field processing with broadband random sources

The goal of this thesis is to introduce new matched field processors (MFPs) for estimating the source location and the environmental parameters of a shallow water waveguide in which the source transmits either broadband or narrowband random signals. The processors provide higher resolution in localizing sources in a noisy environment, and have lower side lobe levels compared to conventional MFPs. MFPs are developed for non-stationary (NS), and wide sense stationary (WSS) random sources. For time varying sources, formulations based on an evolutive spectrum concept are proposed to obtain the advantages of time-frequency analysis. For each of the above formulations, two estimation methods are proposed, a self-CR (cross relation) or a cross-CR according to which output signal channel is used to construct the estimator. In addition, the new high resolution MFPs are also formulated for use with deterministic sources. All the above formulations derive second order MFPs. We extend the second-order cross-relation concept to higher order MFPs.; The MFPs developed in this thesis are applied for source localization and estimation of waveguide model parameters. We propose an adaptive matched field processing system for estimating geoacoustic parameters of the ocean bottom. The method makes use of ambient noise from signals of opportunity such as broadband random signals radiated by passing ships to estimate the geoacoustic properties of a new environment. We also propose a novel phase-regulated back wave propagation (BWP) technique to increase the sensitivity of MFP for geoacoustic model parameters having low sensitivity. We show theoretically that we can increase the sensitivity by a factor using the phase regulation procedure. We also show that the spatial resolution of signal energy that is focused by the BWP algorithm is increased when the sensitivity factor increases. This leads us to define a criterion based on the spatial distribution of signal energy around the true source location. We also propose a multi-step search process to avoid using a complicated multi-dimensional search process. We present an evaluation of new matched field processors for source localization and geoacoustic parameter estimation with other MFPs. The evaluation is conducted using results obtained from both simulation and the Pacific Shelf experiment.