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 20 of 25 for “"side-scan sonar"”.
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Registration and variability of side scan sonar imagery
… the results of several experiments performed on side scan sonar equipment and imagery with the aim of characterizing the acoustic variability of side scan sonar imagery and applying this information to image rectification and registration. A static test tank experiment is presented which analyzes …
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Side scan sonar image formation, restoration and modelling.
… the development of processing algorithms for sonar image enhancement. The thesis is divided into two principal parts. In the first part the statistical properties of side scan sonar images are analysed. Then, based on this analysis, a Maximum A Posteriori (MAP) formulation of the sonar image …
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An electronically focused multiple beam side scan sonar
… cost of the beam forming system. High resolution side scan sonar systems have many operational parameters that may only be extended with the aid of phased arrays, the resolution and the imaging rate being the most important. This thesis describes a microprocessor controlled dynamically focused …
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Estimation and correction of geometric distortions in side-scan sonar images
… images of the bottom of the sea produced by side-scan sonars. Specifically, it addresses the problem of estimating and correcting geometric distortions frequently observed in such images as a consequence of motion instabilities of the sonar array. This procedure estimates the geometric …
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GIS habitat associations of large river fish assemblages from side-scan sonar
Access to abstract permanently restricted to Ball State community only.
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Supervoxel Based Object Detection and Seafloor Segmentation Using Novel 3d Side-Scan Sonar
… and seafloor segmentation for conventional 2D side-scan sonar imagery is a well-investigated problem. However, due to recent advances in sensing technology, the side-scan sonar now produces a true 3D point cloud representation of the seafloor embedded with echo intensity. This creates a need to …
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Status and Distribution of Manatees in Honduras and the Use of Side-Scan Sonar
… with endangered and solitary animals. The use of side-scan sonar, which produces a picture-like image of the substrate and objects in the water column, was explored to acoustically detect West Indian Manatees in various environmental conditions and habitats. Blind transects (observer looked only …
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Habitat Suitability and Availability for Rainbow Trout (Oncorhynchus mykiss) in the Canyon Reservoir Tailrace and Evaluation of Side Scan Sonar for Habitat Mapping in a Semi-Wadable River
… remote sensing, bathymetric mapping, and side scan sonar. Side scan sonar was evaluated for efficiency and applicability to river systems similar to the tailrace. Results indicate that summer water temperature is likely the primary limiting factor for adult trout survival and could impose …
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High resolution seismology, archaeology and submerged landscapes - an interdisciplinary study
… inter-disciplinary survey methodology, utilising side scan sonar, sub-bottom profilers, aerial photography and archaeological field inspection to establish the correct spatial and contextual relationships of submerged archaeological structures. To facilitate survey of the shallow intertidal zone, …
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A Multidisciplinary Investigation of the Intermediate Depths of the Atlantic Ocean: AAIW delta^13C Variability During the Younger Dryas and Lithoherms in the Straits of Florida
… been referred to as lithoherms. We use digital, side-scan sonar data collected from the submarine NR-1 from an 10.9 km^2 area at ~650 m water depth to characterize quantitatively aspects of the morphology of 216. Their lengths, widths, heights, areas, orientations and concentration on the …
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Sediment deposition in the lower Hudson River estuary
… in the estuary are identified through the use of side-scan sonar, bottom penetrating sonar and surficial sediment sampling. Sediment cores are used to document deposit thicknesses and to obtain the spatial distribution of estuarine deposits. Results show a high degree of spatial and temporal …
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The marine geology of Walker Bay, off Hermanus, SW Cape, South Africa
… 4 years, between 1986 and 1990. The data include side-scan sonar images, seismic profiles, seabed samples and observations by a Remotely Operated underwater Vehicle (ROV). Four sonograph facies were identified, based on their distinctly different reflectivity patterns. Using the seabed samples and …
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Wavelet based similarity measurement algorithm for seafloor morphology
… to address the above problem. Our work uses a side-scan sonar image library for experimentation and testing. Variations of an underwater vehicle's height above the sea floor and of its pitch and roll angles cause distortion in the data obtained, such that transformations to align the data …
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Studies of sediments in a tidal environment
… in Plymouth Sound, S.W. England, are defined by side-scan sonar surveys calibrated by direct sampling by SCUBA divers: (i) uniform mud depocentres, (ii) areas of continual sediment reworking, (iii) areas of relict sedimentation, (iv) areas of episodic deposition and, (v) clean-washed rock …
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Sediment circulation in mixed gravel and shingle bayhead beaches on the South East Dorset coast.
… of process response has been adopted which considers energy inputs, sediment transport and coastal morphology, under conditions of limited sediment supply and a "closed cell" situation. Onshore field investigations using conventional methods of surface sediment sampling, together with beach …
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Analysis and modeling of hurricane impacts on a coastal Louisiana lake bottom
… lines of evidence and numerical modeling. Using side-scan sonar, CHIRP subbottom and echo sounder bathymetric profiles, the lake bottom and shallow subsurface of Sister Lake was imaged pre- and post-Hurricanes Katrina and Rita to provide a geologic framework for assessing the effects of these …
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Robotic Search Planning In Large Environments with Limited Computational Resources and Unreliable Communications
… for subsea applications where, due to use of side-scan sonar in search applications, search paths typically consist of parallel straight lines. Thus for subsea search applications, our approach ensures that expected performance is no worse than the usual subsea search path, and it might be …
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The marine geology of Mossel Bay, South Africa
… the Mossel Bay shelf using multibeam bathymetry, side-scan sonar and sub-bottom profiling; and a shallow seismic pinger survey of Swartvlei, the most prominent coastal lake in the Wilderness Embayment. This study presents 9 discrete seismic sequences, and describes major offshore geomorphic …
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The sedimentology and dynamics of mega-dunes, Jamuna river, Bangladesh
… position and high resolution echo sounders and side scan sonar to monitor bed morphology. Flow, turbulence and suspended sediment transport were investigated using an Acoustic Doppler Current Profiler (ADCP) which measured both the instantaneous three-dimensional velocity structure and the …
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