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 15 of 15 for “"Oceanographic instruments"”.
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Instrumentos de queda livre para medição de parâmetros oceanográficos
… work deals with the development of free falling oceanographic instruments. The stability and constant speed during the fall are guaranteed by the action of rotary wings attached to a cilindric body. Signals from the sensors are brought aboard by electrical cable where they feed graphic or …
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The Flying Fish, an untethered oceanographic sensor platform with acoustic homing capability
… vehicle attitude. This thesis describes the oceanographic context in which the vehicle will be used, translates the scientific mission into a set of coherent engineering specifications, describes a prototype design that meets these specifications, and demonstrates proof-of-concept with a …
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Oceanographic Instrument Simulator
… than a deep-water platform as shallow water instruments are less expensive (as it does not have to be designed to withstand the pressure at deep ocean depths) and more easily deployed (they can be deployed right along the coast).</p> <p>The swFOCE experiment is an open source platform, and …
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Ice-ocean interactions beneath the north-western Ross Ice Shelf, Antarctica
… mass loss from the Antarctic Ice Sheet, yet the oceanographic processes which drive this are rarely observed. This thesis uses new observations from phase sensitive radar and moored oceanographic instruments to describe the processes which drive rapid basal melting of the north-western Ross Ice …
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Effects of ocean turbulence on the large-scale stratification and Small-Scale Particle Distributions
… ocean such as plastic debris or freely floating oceanographic instruments may differ from that of the surrounding fluid due to differences in inertia. The details of the deviations of inertial particle trajectories from the fluid velocity field depend on small-scale fluctuations in the fluid …
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The design of an instrument to measure vertically averaged oceanic currents using geomagnetic electric fields
A bottom mounted electromagnetic current meter measures the vertically-averaged conductivity-weighted velocity. This measurement complements free-fall relative velocity profiles and is valuable for transport determination and dynamics studies. Such an instrument has been designed to measure the …
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Analysis and application of an underwater optical-ranging system
In order to provide a high-resolution underwater-ranging capability for scientific measurement, a commercially available optical-ranging system is analyzed for performance and feasibility. The system employs a structured-lighting technique using a laser-light plane and single-camera imaging system. …
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Development of the BASS rake acoustic current sensor : measuring velocity in the continental shelf wave bottom boundary layer
Surface swell over the continental shelf generates a sheet of oscillatory shear flow at the base of the water column, the continental shelf wave bottom boundary layer. The short periods of surface swell sharply limit the thickness of the wave boundary layer, confining it to a thin region below an …
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Measuring surface ocean wave height and directional spectra using an Acoustic Doppler Current Profiler from an autonomous underwater vehicle
The Acoustic Doppler Current Profiler (ADCP) is a proven technology which is capable of measuring surface wave height and directional information, however it is generally limited to rigid, bottom mounted applications which limit its capabilities for measuring deep water waves. By employing an …
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Development of an actively compliant underwater manipulator
This thesis describes the design, construction, and evaluation of an actively compliant underwater manipulator for installation on the underwater remotely operated vehicle (ROV) JASON. The goal of this work has been to produce a high fidelity force-controllable manipulator exhibiting no backlash, …
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Development of an acoustic vorticity meter to measure shear in ocean-boundary layers
… geophysical measurements and translates this oceanographic context into design goals. The instrument was designed, built, tested, and deployed. It measures three-axis vorticity at 0.83 and 2.45 meters below the ocean surface with measurement volumes of 0.45 meters on a side. The instrument …
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Distributional models of ocean carbon export
Each year, surface ocean ecosystems export sinking particles containing gigatons of carbon into the ocean’s interior. This particle flux connects the entire ocean microbiome and constitutes a fundamental aspect of marine microbial ecology and biogeochemical cycles. Particle flux is also variable …
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Oceanic microstructure observed near Bermuda using a towed sensor
Many hypotheses have been advanced to explain the formation of mixed layers in the ocean; the salt finger type of double-diffusive convection, in particular, has received much attention. Because of their uniquely ordered nature, salt fingers should be readily identifiable in the deep thermocline, …
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A study of the velocity structure in a marine boundary layer : instrumentation and observations
The design and operation of a unique flow measuring instrument for bottom boundary layer studies in the marine environment is documented. The effectiveness of the instrument in acquiring data with which models of near bottom flows in the ocean can be tested is demonstrated by the results of a field …
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Development and application of a field instrumentation system for the investigation of surf zone hydrodynamics
The development and application of an autonomous field instrumentation system consisting of four current meters and four wave gauges, along with a field monitor and digital recorder, is documented. The flow sensors are electromagnetic current meters, which employ the principle of electromagnetic …