Ocean Engineering Commons^™

Extending Low-Frequency Traveling-Wave Propagation In A Water-Filled Cylindrical Waveguide Using Active Impedance Control, William Slater

Open Access Dissertations

This dissertation investigates extending the frequency range over which a one-dimensional, plane traveling wave can be generated in a water-filled, steel-walled waveguide under ocean temperature and hydrostatic pressure conditions. The wave guide considered is a thick-walled, steel cylinder filled with a water/glycol mixture with a transducer at each end and a hydrophone array along the length. One transducer excites a plane wave while the other cancels reflections, resulting in a traveling wave in the waveguide. The current (open-loop) measurement system is advertised to generate traveling waves for low frequencies where only 3.4% of a wavelength can be measured (kL …

Development And Deployment Of In Situ Fiber Optic Distributed Temperature Sensing Systems And Data Processing Workflows For Oceanographic Observatories In Coastal And Deep-Sea Environments, Johann Sebastian Becker

Open Access Dissertations

Over the last two decades, fiber optic distributed temperature sensing (DTS) has emerged as a transformative technology capable of providing unprecedented spatiotemporal resolution observations of temperature in a broad range of environmental sensing, industrial, and civil engineering monitoring applications. DTS uses a single interrogator unit to measure temperature continuously along an optical fiber, effectively turning the fiber into the equivalent of an array of temperature probes that can be interrogated synoptically. Modern commercially-available DTS systems are capable of continuous sensing with sampling frequencies up 5 sec, spatial resolution of 0.25 m, and temperature precision up to 0.01 °C) observations, on …

Reverse Geometric Dispersion In The Beaufort Sea: Dissecting Sound Propagation At Long Ranges In Ducted Profiles, Jessica Desrochers

Open Access Dissertations

Acoustic propagation in the Arctic is evolving as surface temperatures increase and ice melts, resulting in a changing sound propagation environment. This study investigates the acoustic arrival structure in the Canada Basin and its connection to the underlying sound speed profiles. Two Seagliders were deployed in the summer of 2016 and 2017, diving in a sawtooth pattern collecting conductivity, temperature, and depth (CTD) data as part of the Canada Basin Acoustic Glider Experiment (CABAGE). These data are used to calculate sound speed profiles used to predict and understand acoustic arrival structures.

The warming of the Pacific Summer Water and surface …