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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Linear refraction-differaction model for steep bathymetry

Chandrasekera, Carmela Nilmini. January 2000 (has links)
Thesis (Ph. D.)--University of Hawaii at Manoa, 2000. / Includes bibliographical references (leaves 102-106). Also available on microfiche.
2

Separation of regional and residual components of bathymetry using directional median filtering /

Kim, Seung-Sep. January 2005 (has links)
Thesis (M.S.)--University of Hawaii at Manoa, 2005. / Includes bibliographical references (leaves 47-49). Also available by World Wide Web.
3

Self consistent bathymetric mapping from robotic vehicles in the deep ocean /

Roman, Christopher N. January 1900 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2005. / Bibliography: p. 119-129.
4

Video-based nearshore depth inversion using WDM method

Hampson, Robert W.. January 2009 (has links)
Thesis (M.C.E.)--University of Delaware, 2008. / Principal faculty advisor: James T. Kirby, Dept. of Civil & Environmental Engineering. Includes bibliographical references.
5

Long-term tide and wave-induced sedimentation at a lagoon entrance

Samarawickrama, Saman Priyantha January 1999 (has links)
No description available.
6

Using Genetic Algorithms to Optimize Bathymetric Surveys for Hydrodynamic Model Input

Manian, Dinesh 2009 December 1900 (has links)
The first part of this thesis deals with studying the effect of the specified bathymetric resolution and ideal bathymetric form parameters on the output from the wave and hydrodynamic modules of Delft-3D. This thesis then describes the use of an optimization to effectively reduce the required bathymetric sampling for input to a numerical forecast model, by using the model’s sensitivity to this input. A genetic algorithm is developed to gradually evolve the survey path for a ship, AUV, or other measurement platform to an optimum, with the resulting effect of the corresponding measured bathymetry on the model, used as a metric. Starting from an initial simulated set of possible random or heuristic sampling paths over the given bathymetry using certain constraints like limited length of track, the algorithm can be used to arrive at the path that would provide the best possible input to the model under those constraints. This suitability is tested by a comparison of the model results obtained by using these new simulated observations, with the results obtained using the best available bathymetry. Two test study areas were considered, and the algorithm was found to consistently converge to a sampling pattern that best captured the bathymetric variability critical to the model prediction.
7

A study of the target detection capabilities of an airborne lidar bathymetry system

Carr, Domenic Anthony 18 March 2013 (has links)
Airborne lidar bathymetry (ALB) is a method used to survey and map coastal and littoral zones. Along with extracting seafloor depth and reflectance in the surveyed area, a fundamental requirement of these surveys is to detect underwater targets, hazards, or obstructions. The ability to detect underwater targets depends on a target's dimensions and reflectance, the depth and turbidity of the water, system and survey configuration, data processing capabilities, and algorithmic sophistication. Understanding the effects of each of these factors on the performance of underwater target detection is essential in determining the target detection capabilities of a proposed ALB system. After detailing the development of a simulation environment to model received ALB system waveforms, this work explores the theoretical target detection capabilities of an ALB system.
8

Using Genetic Algorithms to Optimize Bathymetric Surveys for Hydrodynamic Model Input

Manian, Dinesh 2009 December 1900 (has links)
The first part of this thesis deals with studying the effect of the specified bathymetric resolution and ideal bathymetric form parameters on the output from the wave and hydrodynamic modules of Delft-3D. This thesis then describes the use of an optimization to effectively reduce the required bathymetric sampling for input to a numerical forecast model, by using the model’s sensitivity to this input. A genetic algorithm is developed to gradually evolve the survey path for a ship, AUV, or other measurement platform to an optimum, with the resulting effect of the corresponding measured bathymetry on the model, used as a metric. Starting from an initial simulated set of possible random or heuristic sampling paths over the given bathymetry using certain constraints like limited length of track, the algorithm can be used to arrive at the path that would provide the best possible input to the model under those constraints. This suitability is tested by a comparison of the model results obtained by using these new simulated observations, with the results obtained using the best available bathymetry. Two test study areas were considered, and the algorithm was found to consistently converge to a sampling pattern that best captured the bathymetric variability critical to the model prediction.
9

Effects from uncertainties in bathymetric measurements and variability in topography on computed stability of offshore slopes in deep water /

Liedtke, Eric Arthur, January 2001 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references (leaves 379-383). Available also in a digital version from Dissertation Abstracts.
10

Mapping bathymetry : From measurement to applications

Hell, Benjamin January 2011 (has links)
Surface elevation is likely the most fundamental property of our planet. In contrast to land topography, bathymetry, its underwater equivalent, remains uncertain in many parts of the World ocean. Bathymetry is relevant for a wide range of research topics and for a variety of societal needs. Examples, where knowing the exact water depth or the morphology of the seafloor is vital include marine geology, physical oceanography, the propagation of tsunamis and documenting marine habitats. Decisions made at administrative level based on bathymetric data include safety of maritime navigation, spatial planning along the coast, environmental protection and the exploration of the marine resources. This thesis covers different aspects of ocean mapping from the collection of echo sounding data to the application of Digital Bathymetric Models (DBMs) in Quaternary marine geology and physical oceanography. Methods related to DBM compilation are developed, namely a flexible handling and storage solution for heterogeneous sounding data and a method for the interpolation of such data onto a regular lattice. The use of bathymetric data is analyzed in detail for the Baltic Sea. With the wide range of applications found, the needs of the users are varying. However, most applications would benefit from better depth data than what is presently available. Based on glaciogenic landforms found in the Arctic Ocean seafloor morphology, a possible scenario for Quaternary Arctic Ocean glaciation is developed. Our findings suggest large ice shelves around parts of the Arctic Ocean during Marine Isotope Stage 6, 130–200 ka. Steered by bathymetry, deep water from the Amerasian Basin of the Arctic Ocean flows over the central Lomonosov Ridge into the Eurasian Basin. This water mass is traced on its continuing way towards Greenland and the Fram Strait. At the Morris Jesup Rise, bathymetry plays an important role in the partial re-circulation of the water into the Amerasian Basin. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Manuscript. Paper 3: Submitted.</p>

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