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 8 of 8 for “"Underwater acoustic telemetry"”.
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Characterization of underwater target geometry from Autonomous Underwater Vehicle sampling of bistatic acoustic scattered fields
One of the long term goals of Autonomous Underwater Vehicle (AUV) minehunting is to have multiple inexpensive AUVs in a harbor autonomously classify hazards. Existing acoustic methods for target classification using AUV-based sensing, such as sidescan and synthetic aperture sonar, require an …
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Analysis of and techniques for adaptive equalization for underwater acoustic communication
Underwater wireless communication is quickly becoming a necessity for applications in ocean science, defense, and homeland security. Acoustics remains the only practical means of accomplishing long-range communication in the ocean. The acoustic communication channel is fraught with difficulties …
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Quantification of the spatial and temporal evolution of stratified shear instabilities at high Reynolds number using quantitative acoustic scattering techniques
… The measurements are made using high-resolution acoustic backscatter from an array composed of six calibrated broadband transducers connected to a six-channel high-frequency (120-600 kHz) broadband acoustic backscatter system. The array was mounted on the bottom of the estuary and looking upward. …
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Toward autonomous underwater mapping in partially structured 3D environments
Motivated by inspection of complex underwater environments, we have developed a system for multi-sensor SLAM utilizing both structured and unstructured environmental features. We present a system for deriving planar constraints from sonar data, and jointly optimizing the vehicle and plane positions …
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Controller design for underwater vehicle systems with communication constraints
… feature, but relies on wireless communications. Underwater communication is almost exclusively accomplished through acoustics, which bring challenges such as delays, low data rates, packet loss, and scheduling constraints. To address these challenges, this thesis presents contributions towards …
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A distributed approach to underwater acoustic communications
A novel distributed underwater acoustic networking (UAN) protocol suitable for ad-hoc deployments of both stationary and mobile nodes dispersed across a relatively wide coverage area is presented. Nodes are dynamically clustered in a distributed manner based on the estimated position of one-hop …
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Evaluation of vector sensors for adaptive equalization in underwater acoustic communication
Underwater acoustic communication is an extremely complex field that faces many challenges due to the time-varying nature of the ocean environment. Vector sensors are a proven technology that when utilizing their directional sensing capabilities allows us to minimize the effect of interfering noise …
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Progressively communicating rich telemetry from autonomous underwater vehicles via relays
… a significant challenge – as a result, current telemetry from free-roaming autonomous marine vehicles remains limited to ‘heartbeat’ status messages, with minimal scientific data available until after recovery. Increasing the challenge, longdistance communication may require relaying data across …