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Now showing items 21-30 of 44
A planned approach to high collision risk area
(Massachusetts Institute of Technology, 2020)
This thesis examines the transition of a vessel from the open ocean, where collisions are rare, to a high risk and heavy traffic area such as a Traffic Separation Scheme (TSS). Previous autonomy approaches generally view ...
Robust acoustic signal detection and synchronization in a time varying ocean environment
(Massachusetts Institute of Technology, 2012)
Signal detection and synchronization in the time varying ocean environment is a difficult endeavor. The current common methods include using a linear frequency modulated chirped pulse or maximal length sequence as a detection ...
Verification of a six-degree of freedom simulation model for the REMUS autonomous underwater vehicle
(Massachusetts Institute of Technology, 2001)
mproving the performance of modular, low-cost autonomous underwater vehicles (AUVs) in such applications as long-range oceanographic survey, autonomous docking, and shallow-water mine countermeasures requires improving the ...
Modeling wind forcing in phase resolving simulation of nonlinear wind waves
(Massachusetts Institute of Technology, 2010)
Wind waves in the ocean are a product of complex interaction of turbulent air flow with gravity driven water surface. The coupling is strong and the waves are non-stationary, irregular and highly nonlinear, which restricts ...
Real time bottom reverberation simulation in deep and shallow ocean environments
(Massachusetts Institute of Technology, 2015)
Due to the costs involved and time required to perform experiments at sea, it is important to provide accurate simulations of the ocean environment. Using the ray tracing code, BELLHOP, the Mission Oriented Operating Suite ...
Seafloor ripples created by waves from hurricane Ivan on the west Florida shelf
(Massachusetts Institute of Technology, 2006)
Recent studies have shown that the presence of sand ripples on the seabed improves sonar detection of buried mines at sub-critical angles. Sidescan sonar data of ripples off on the west Florida shelf were collected as part ...
Field deployable dynamic lighting system for turbid water imaging
(Massachusetts Institute of Technology, 2011)
The ocean depths provide an ever changing and complex imaging environment. As scientists and researches strive to document and study more remote and optically challenging areas, specifically scatter-limited environments. ...
A computational tool for the rapid design and prototyping of propellers for underwater vehicles
(Massachusetts Institute of Technology, 2007)
An open source, MATLABTM-based propeller design code MPVL was improved to include rapid prototyping capabilities as well as other upgrades as part of this effort. The resulting code, OpenPVL is described in this thesis. ...
Scattering of the low-mode internal tide at the Line Islands Ridge
(Massachusetts Institute of Technology, 2015)
The scattering of low-mode internal tides by ocean-floor topography is extensively studied through analytical models and field observations at the Line Islands Ridge (LIR). An existing Green function method is utilized to ...
Low frequency active sonar performance in the Arctic Beaufort Lens
(Massachusetts Institute of Technology, 2017)
A newly discovered double ducted acoustic environment present throughout much of the Beaufort Sea in the Arctic has a major effect on active acoustic transmissions. This work performs an in depth analysis of how the lower ...