Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 12 of 12 for “"Synthetic aperture sonar"”.
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Synthetic aperture sonar for sub bottom imaging
The major problems associated with implementing synthetic apertures in sonar may be overcome by applying the technique to sub-bottom imaging. The use of a low frequency aids both penetration of the sediment and the attainment of long coherent apertures. The implementation of synthetic apertures …
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Multiple transducer synthetic aperture sonar interferometry for emulating SAR interferometry
Multiple transducer single-pass synthetic aperture sonar interferometry in air is a technique that can emulate topographic mapping techniques that have not been implemented using radar or that are relatively expensive and difficult to obtain in practice for the radar engineer who wishes to test …
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Ocean, platform, and signal processing effects on synthetic aperture sonar performance
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1991.
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Synthetic aperture sonar imaging using compressive sensing and an ultrasound transducer array
… resonance imaging (MRI), X-ray CT, and in 3D synthetic aperture radar (SAR) imaging for reconstructing the elevation reflectivity profile. This dissertation describes the investigation into three-dimensional (3D) synthetic aperture sonar (SAS) imaging in air using compressive sampling. In the …
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Interferometric Synthetic Aperture Sonar Signal Processing for Autonomous Underwater Vehicles Operating Shallow Water
<p>The goal of the research was to develop best practices for image signal processing method for InSAS systems for bathymetric height determination. Improvements over existing techniques comes from the fusion of Chirp-Scaling a phase preserving beamforming techniques to form a SAS image, an …
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Detection of multiple correlated time series and its application in synthetic aperture sonar imagery
… monitoring of seismic activity, radar, and sonar. Some detection systems in such situations use decision fusion to combine individual detection decisions into one global decision. However, this detection paradigm can be sub-optimal as local decisions are based on the perspective of a single …
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MIMO radar: signal processing, waveform design, and applications to synthetic aperture imaging
… the image quality and area-coverage rate of synthetic aperture imaging systems. A signal processing architecture for MIMO radar is used to understand the applicability of MIMO for synthetic aperture radar (SAR) and synthetic aperture sonar (SAS) systems. MIMO SAR/SAS is shown to be a natural …
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Acoustic classification of buried objects with mobile sonar platforms
In this thesis, the use of highly mobile sonar platforms is investigated for the purpose of acoustically classifying compact objects on or below the seabed. The extension of existing strategies, including synthetic aperture sonar and conventional imaging, are explored within the context of the …
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Dynamic sonar perception
Reliable sonar perception is a prerequisite of marine robot feature-based navigation. The robot must be able to track, model, map, and recognize aspects of the underwater landscape without a priori knowledge. This thesis explores the tracking and mapping problems from the standpoint of …
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Underwater multi-vehicle co-operative target-tracking
… presented here utilizes the technique of synthetic aperture sonar (SAS) to relate disparate acoustic measurements in a consistent probabilistic framework. Experimental results under real-world acoustic conditions are gathered onboard our custom-built lightweight and low-cost ASVs in the …
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Characterization of underwater target geometry from Autonomous Underwater Vehicle sampling of bistatic acoustic scattered fields
… using AUV-based sensing, such as sidescan and synthetic aperture sonar, require an expensive payload on each outfitted vehicle and expert image interpretation. This thesis proposes a vehicle payload and machine learning classification methodology using bistatic angle dependence of target …
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Characterization of underwater target geometry from autonomous underwater vehicle sampling of bistatic acoustic scattered fields
… using AUV-based sensing, such as sidescan and synthetic aperture sonar, require an expensive payload on each outfitted vehicle and expert image interpretation. This thesis proposes a vehicle payload and machine learning classification methodology using bistatic angle dependence of target …