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Showing 1 to 14 of 14 for “"Matched Field Processing"”.
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Adaptive matched field processing in an uncertain propagation environment
Adaptive array processing algorithms have achieved widespread use because they are very effective at rejecting unwanted signals (i.e., controlling sidelobe levels) and in general have very good resolution (i.e., have narrow mainlobes). However, many adaptive high-resolution array processing …
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A matched field processing approach to long range acoustic navigation
This thesis presents the design and simulation of an acoustic listen-only navigation system for use in a time-varying high-multipath environment. The system uses a ray tracing model of sound propagation in a horizontally stratified ocean to associate each multipath arrival with a particular ray …
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A matched field processing approach to long range acoustic navigation
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1994.
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Stochastic matched field processing for localization and nulling of acoustic sources
Thesis (Sc.D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2000.
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Surface wave, internal wave, and source motion effects on matched field processing in a shallow water waveguide
Given well known environmental conditions, matched field processing has been shown to be a promising signal processing technique for the localization of acoustic sources. However, when environmental data are incomplete or inaccurate, a 'mismatch' occurs between the measured field and model field …
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Improvement of three dimensional acoustic field estimation using tomographic reconstructions of the ocean
… sound speed structure in improving acoustic field predictions for source localization, a 150 km by 350 km volume of ocean 3000 meters deep was synthetically modeled to be similar to the Gulf Stream system, including an eddy and a front. The features were Gaussian, with the eddy's maximum …
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Sequential bayesian filtering for spatial arrival time estimation
… 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 …
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Efficient inversion methods in underwater acoustics
… using linearization is also compared to matched-field processing, which estimates source location and geoacoustic parameters through a full field matching approach.
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Application of the Method of Least Squares to a Solution of the Matched Field Localization Problem with a Single Hydrophone
… hydrophone localization is a special case of matched field localization where measurements from only one hydrophone are available. The time series of the pressure at the hydrophone is compared with predicted times series calculated using an ocean acoustic propagation model for many different …
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Ambient acoustics as indicator of environmental change in the Beaufort Sea: experiments & methods for analysis
… depth mismatch is compared with conventional matched field processing. We further explore how the CNN approach achieves its performance by examining its intermediate outputs. Another tool is a frequency domain, transient event detection algorithm that leverages image processing and …
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Ambient Acoustics as Indicator of Environmental Change in the Beaufort Sea: Experiments & Methods for Analysis
… depth mismatch is compared with conventional matched field processing. We further explore how the CNN approach achieves its performance by examining its intermediate outputs. Another tool is a frequency domain, transient event detection algorithm that leverages image processing and …
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Multiarray Passive Acoustic Localization and Tracking
… propagation scenarios is addressed: the free-field assumption and the general case. In both cases, it is found that performance is highly dependent on the array-source geometry which in turn drives the design of localization strategies. First, the general surveillance problem including signal …
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Acoustic source localization in 3D complex urban environments
… noise in the environment. Multiple-array processing is also considered to improve the overall localization performance. The sensitivity of the beamformers to uncertainties that cannot be easily accounted for (e.g. temperature gradient and unmodeled object) is then investigated. It is …
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Higher order asymptotic inference in remote sensing of oceanic and planetary environments
… as speckle, which arises from complex Gaussian field fluctuations. We find that single-sample orientation estimates have biases and errors that vary dramatically depending on illumination direction measurement diversity due to the signal-dependent nature of speckle noise and the nonlinear …