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 1155 for “"Underwater"”.
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Underwater & out of sight: towards ubiquity in underwater robotics
… creatures that inhabit its waters. Autonomous underwater vehicles (AUVs) hold the promise of penetrating the ocean environment and uncovering its mysteries; and progress in underwater robotics research over the past three decades has resulted in vehicles that can navigate reliably and operate …
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Underwater & out of sight : towards ubiquity in underwater robotics
… creatures that inhabit its waters. Autonomous underwater vehicles (AUVs) hold the promise of penetrating the ocean environment and uncovering its mysteries; and progress in underwater robotics research over the past three decades has resulted in vehicles that can navigate reliably and operate …
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Analog Underwater Backscatter: Networked Underwater Sensing at Microwatt Power Levels
We present Analog Underwater Backscatter (AUB), the first technology for microwatt-level underwater wireless sensor networks. AUB departs from past underwater backscatter technologies in that it encodes sensor data directly into the physical layer through analog (frequency) modulation. Our design …
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Bearing Estimation for Underwater Acoustic Source Using Autonomous Underwater Vehicle
… sources of acoustic noise using an autonomous underwater vehicle (AUV) in real world environments. The initial part of this thesis describes the developments made for redesigning an acoustic sensing system that can be used to estimate the relative bearing between a source of acoustic noise and …
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Underwater turbidity measurements
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Geology and Geophysics, 1960.
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Forces on underwater vehicles
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1995.
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Tracking an underwater target
Autonomous underwater vehicles are becoming an important part in marine research. In order to help bring down the cost of running a research mission with an autonomous underwater vehicle (AUV), the method of tracking the AUV can be improved. An autonomous surface vessel (ASV), equipped with both …
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Underwater sound puluse generator
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1996.
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Precision autonomous underwater navigation
… an emerging application of autonomous underwater vehicle (AUV) technology, requires precise navigation and guidance. As science requirements and engineering capabilities converge, navigating in the sensor-limited ocean remains a fundamental challenge. Despite the logistical cost, the …
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Mobile Underwater Backscatter Networking
Underwater backscatter is a recently introduced technology for ultra-low-power underwater networking. Despite advances in this technology, existing systems are limited to static environments and cannot operate reliably under mobility. This thesis presents EchoRider, the first system that enables …
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Design of an Autonomous Underwater Vehicle (AUV) charging system for underway, underwater recharging
… enabled the rapid proliferation of Autonomous Underwater Vehicles (AUVs) throughout the marine environment. As autonomy algorithms increase in robustness, complexity, and reliability, so too does the ability of AUVs to perform an even-increasing array of complex missions. Maritime tasks that …
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Sound propagation around underwater seamounts
… the understanding of sound propagation around underwater seamounts. The depth-dependent sound velocity profile of typical ocean waveguides force sound to travel in convergence zones about a minimum sound speed depth. This ducted nature of the ocean makes modeling the acoustic field around …
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Adaptive reception for underwater communications
… the development of an adaptive receiver for underwater communication. In this type of wireless link, the radio channel is replaced by an underwater acoustic channel, which is strongly dependent on the physical properties of the ocean medium and its boundaries, the link geometry and the …
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Underwater acoustics in arctic environments
Includes bibliographical references (leaves 46-47).
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Empirical investigation of underwater blast
… effective placement. It should be noted that an underwater charge can be used in two distinctly different types of application against a target ' a large charge at a distance from the target (eg a torpedo) or a small charge in direct contact (eg demolition charge or limpet mine). In the first …
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Sound propagation around underwater seamounts
… long-ranges, making them an effective tool for underwater source localization, tomography, and communications. Underwater mountains, or seamounts, are ubiquitous throughout the world's oceans and can absorb and scatter acoustic energy, offering many interesting acoustic modeling challenges. The …
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Sound propagation around underwater seamounts
… the understanding of sound propagation around underwater seamounts. The depth-dependent sound velocity profile of typical ocean waveguides force sound to travel in convergence zones about a minimum sound speed depth. This ducted nature of the ocean makes modeling the acoustic field around …
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OFDM for Underwater Acoustic Communication
Communicating wirelessly underwater has been an area of interest for researchers, engineers, and practitioners alike. One of the main reasons for the slow rate of progress in this area is that the underwater acoustic channel is in general much more hostile — in terms of multipath, frequency …
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Autonomous Underwater Vehicle Propulsion Design
… propulsive system for the candidate autonomous underwater vehicle (AUV) as possible. A mathematical approach, using fundamental motor equations and derived quantities, was used to characterize and select an efficient brushless electric motor for the propulsion system. A program developed at MIT, …
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