Adaptive Methods in Underwater Acoustics

Abstract

1. Acoustical Background of Signal Processing.- Twenty years of signal processing.- Ambient noise: characteristics of the noise field.- An analytical method to predict the statistical characteristics of ambient shipping noise.- Statistical aspects of sound propagation in the ocean.- Towed array response to ship noise: a near-field propagation problem.- Three-dimensional FFP model of acoustic- and elastic wave propagation in horizontally layered media.- Seismic sensors in underwater acoustics: results from sea-floor measurements in areas of different geology.- Underwater acoustics in the Arctic Ocean.- A new theory for the transmission and reflection coefficient of layered systems.- Second moments of the pressure field near a smooth caustic.- Stochastic systems theory of the scattering of waves from a random medium.- Hydrodynamic flow noise in hydrophones.- Wavevector structure of turbulent wall pressure and its filtering by normal transmission and spatial averaging in sensor arrays.- Target strength and echo structure.- 2. Theoretical and Practical Aspects of Signal Processing.- Time delay estimation.- Time delay estimation in the presence of multipath propagation.- Constrained time delay estimation via zero-crossing methods.- Range and bearing determination: Maximum Likelihood and Kalman-Bucy techniques.- Delay estimation with nonstationary signals and correlated observation noises.- Source parameter estimation by approximate Maximum Likelihood.- On the use of focused horizontal arrays as mode separation and source location devices in ocean acoustics.- High-resolution source-depth estimation in ice covered shallow water.- Spectrum analysis: overview of classical and high resolution spectral estimation.- Application of high resolution spatial processing methods to real data of a fixed array in shallow water.- Experimentation of spatial processing methods.- Simultaneous estimation of spectral lines and of a superimposed continuous spectral density.- Fitting sinusoids to sampled data and correlation sequences.- An extended maximum entropy method for high resolution spatial processing.- Spectral and interspectral analysis of low frequency submarine acoustic signals received on an array of sensors.- Overview of adaptive array processing.- New approaches in the adaptive array processing field.- Multiple detection using eigenvalues when the noise spatial coherence is partially unknown.- Theoretical and experimental comparisons of optimum element, beam and eigen space array processors.- Applications of some statistical measures to spatial signal processing.- The cross correlation matrix in spatial processing.- The effect of bandwidth on the performance of a postbeamformer interference canceller.- A new approach to the design of broadband element space antenna array processors.- On the role of prior information in nonlinear bearing estimation.- Beamforming by the cross-correlation analysis of received spectra.- Applications of adaptive array processing.- Adaptive active sonar reception in shallow water using vertical array outputs covariance matrix eigenvalues: experimental results.- Beamforming with a distorted towed array.- Influence of hydrophone position errors on spatial signal processing algorithms.- A tutorial introduction to nonlinear filtering.- Detection with uncertainty: Nonparametric, robust or adaptive approaches.- The design of optimal processors for arrays with non-Gaussian noise inputs.- Adaptive processing of underwater acoustic signals in non-Gaussian noise environments: I. Detection in the space-time threshold regimes.- Detection and classification phenomena of biological systems.- Detection and recognition of moving or randomly scaled objects.- Iterative algorithms for deconvolution and reconstruction of multidimensional signals from their projections.- 3. Techniques and Applications.- Digital signal processing for sonar.- Optical signal processing.- Beamforming for sonar signals by means of an incoherent acousto-optical processor: experimental results.- Adaptation of fiber optics to hydrophone applications.- Ceramic elastomer composite hydrophone.- Expert systems for ship noise interpretation.- Comparison of the statistical and the expert system approach for the interpretation of ship noise.- Signal processing techniques to analyse and simulate radiated underwater ship propeller noise.- Signal processing in ocean tomography.- New advances towards ocean, acoustics and space integration.- Passive synthetic aperture sonar - an analysis of the beamforming process.- Techniques for measuring backscattering from the sea floor with an array.- AEON - adaptive time-space array processing.- Summaries of Workshops.