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Pose Detection And Control Of Unmanned Underwater Vehicles (Uuvs) Utilizing An Optical Detector Array, Firat Eren

Doctoral Dissertations

As part of the research for development of a leader-follower formation between unmanned underwater vehicles (UUVs), this study presents an optical feedback system for UUV navigation via an optical detector array. Capabilities of pose detection and control in a static-dynamic system (e.g. UUV navigation into a docking station) and a dynamic-dynamic system (e.g. UUV to UUV leader-follower system) are investigated. In both systems, a single light source is utilized as a guiding beacon for a tracker/follower UUV. The UUV uses an optical array consisting of photodiodes to receive the light field emitted from the light source.

For UUV navigation applications, …

Ripple Migration And Boundary Layer Dynamics On A Natural Sand Bed, Emily Carlson

Master's Theses and Capstones

A laboratory study was conducted in a field scale flume to further examine the very near-bed dynamics in the near-shore environment using natural, non-cohesive sediments with d50 = 0.22 mm. A Particle Imaging Velocimetry (PIV) system was used to capture the dynamics of the movable ripple bed and the 2D flow field in the vertical (z) and along-tank (x) direction in 1.6 m still water depth. Two wave types were analyzed: regular waves with periods ranging from 4 s to 8 s and bimodal wave pairs with periods of 3.7 and 4.3 s. Orbital ripples developed in all wave environments …

Characterizing And Quantifying Marine Methane Gas Seeps Using Acoustic Observations And Bubble Dissolution Models, Liam Pillsbury

Master's Theses and Capstones

A method for characterizing and quantifying marine methane gas seeps along the U.S. Western Atlantic Margin was developed and applied to 70 free-gas seeps observed by the R/V Okeanos Explorer in 2012 and 2013, in water depths ranging from 300-2000 meters. Acoustic backscatter from an 18 kHz split-beam echo sounder and a 30 kHz multi-beam echo sounder provided information on the height to which the gas seeps rose from the seafloor. Profiles of the depth-dependent target strength and scattering strength were compared to models of the evolution of rising bubbles to help constrain the ultimate fate of the methane gas. …

Critical Shear Stress Estimates Of Sunken Alberta Bitumen, Charles Bruno Richter Watkins

Master's Theses and Capstones

As observed in several recent spills (e.g., DBL-152, TX; Enbridge-Kalamazoo, MI), under certain circumstances, released oil can sink to the bottom of a water body. Once on the bottom, the oil can move or remobilize into the water column. The National Oceanic and Atmospheric Administration’s (NOAA) Office of Response and Restoration (ORR) uses mathematical models to predict the trajectory of spilled oil. The critical shear stress (CSS) for an oil is used to predict the movement of sunken oil along and off the bottom. The CSS has only been measured for one oil (Hibernian crude). The Coastal Response Research Center …