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1
Stuffle, L. Douglas. "Bathymetry from hyperspectral imagery." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1996. http://handle.dtic.mil/100.2/ADA329389.
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Thesis (M.S. in Physics) Naval Postgraduate School, Dec. 1996.<br>Thesis advisors, Richard Christopher Olsen, Newell Garfield. AD-A329 389. Includes bibliographical references (p. 73-75). Also available online.
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Carmody, James Daniel Physical Environmental & Mathematical Sciences Australian Defence Force Academy UNSW. "Deriving bathymetry from multispectral and hyperspectral imagery." Awarded by:University of New South Wales - Australian Defence Force Academy. School of Physical, Environmental and Mathematical Sciences, 2007. http://handle.unsw.edu.au/1959.4/38654.
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Knowledge of water depth is a crucial for planning military amphibious operations. Bathymetry from remote sensing with multispectral or hyperspectral imagery provides an opportunity to acquire water depth data faster than traditional hydrographic survey methods without the need to deploy a hydrographic survey vessel. It also provides a means of collecting bathymetric data covertly. This research explores two techniques for deriving bathymetry and assesses them for use by those involved in providing support to military operations. To support this aim a fieldwork campaign was undertaken in May, 2000, in northern Queensland. The fieldwork collected various inherent and apparent water optical properties and was concurrent with airborne hyperspectral imagery collection, space-based multispectral imagery collection and a hydrographic survey. The water optical properties were used to characterise the water and to understand how they affect deriving bathymetry from imagery. The hydrographic data was used to assess the performance of the bathymetric techniques. Two methods for deriving bathymetry were trialled. One uses a ratio of subsurface irradiance reflectance at two wavelengths and then tunes the result with known water depths. The other inverts the radiative transfer equation utilising the optical properties of the water to derive water depth. Both techniques derived water depth down to approximately six to seven metres. At that point the Cowley Beach waters became optically deep. Sensitivity analysis of the inversion method found that it was most sensitive to errors in vertical attenuation Kd and to errors in transforming the imagery into subsurface irradiance reflectance, R(0-) units. Both techniques require a priori knowledge to derive depth and a more sophisticated approach would be required to determine water depth without prior knowledge of the area of interest. This research demonstrates that water depth can be accurately mapped with optical techniques in less than ideal optical conditions. It also demonstrates that the collection of inherent and apparent optical properties is important for validating remotely sensed imagery.
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Ray, Timothy Allen. "Wave propagation over complex bathymetry." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Jun%5FRay.pdf.
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Thesis (M.S. in Physical Oceanography)--Naval Postgraduate School, June 2003.<br>Thesis advisor(s): Thomas H.C. Herbers, Edward B. Thornton. Includes bibliographical references (p. 37). Also available online.
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Hodul, Matus. "Photogrammetric Bathymetry for the Canadian Arctic." Thesis, Université d'Ottawa / University of Ottawa, 2018. http://hdl.handle.net/10393/37553.
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This study proposes and demonstrates a through-water photogrammetry approach for Satellite Derived Bathymetry (SDB), which may be used to map nearshore bathymetry in the Canadian Arctic. A four step process is used: First, a standard photogrammetric extraction is performed on 2 m resolution WorldView stereo imagery, then apparent depths are calculated by referencing submerged points to the extracted elevation of the water level seen in the image. Due to the effects of refraction, these apparent depths are underestimates, and a refraction correction factor is applied to convert to actual depths. Finally, tidal stage at the time of image acquisition is used to bring depths to chart datum. A post processing step may be applied to remove erroneous depths caused by water surface objects such as boats, debris, or large waves. This was demonstrated in six study areas across Nunavut, Canada to test its robustness under a variety of environmental conditions, including different seafloor types, and under varying sea states. The six study sites were (with vertical accuracy given in Root Mean Square Error/and vertical bias, both in meters): eastern Coral Harbour (1.18/0.03), western Coral Harbour (0.78/-0.32), Cambridge Bay (1.16/0.08), Queen Maud Gulf (0.97/0.13), Arviat (1.02/0.13), and Frobisher Bay, where bathymetry extraction largely failed due to unfavourable sea surface conditions. These findings show that the proposed method has similar or better vertical accuracy as currently established SDB approaches; however, it has several benefits over the established methods which make it better suited for the Arctic. Namely, not requiring the precise atmospheric correction necessary for physics-based models, which is difficult at high latitudes; as well as being able to function in heterogeneous seafloor environments and not needing in-situ calibration data like the empirical spectral ratio approach, better suiting it to remote Arctic waters which often lack existing bathymetric survey data.
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Sproule, David Surveying & Spatial Information Systems Faculty of Engineering UNSW. "Prediction of offshore gravity from bathymetry." Awarded by:University of New South Wales. School of Surveying and Spatial Information Systems, 2005. http://handle.unsw.edu.au/1959.4/22481.
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The definition of the shape of the geoid is a fundamental objective of geodesy, since it allows for the conversion between orthometric and ellipsoidal height systems. The geoid can be computed from gravity values measured over the surface of the earth, and considerable effort continues to achieve a global coverage of gravity values. One technique that has been very successful in recent years in providing gravity coverage in areas which previously have been too difficult to access is airborne gravimetry. This technique has proved very useful in covering near offshore regions, for example. The coastal regions of Australia are recognised as locations where airborne gravimetry has the potential to fill in missing gravity data. A pilot survey using an airborne gravity meter was undertaken off the north east coast of Australia. In areas that remain unsurveyed it is sometimes useful to fill in the missing gravity data values with predicted gravity values. Previous research has examined the possibility of predicting gravity values from other observed quantities. The best success has been achieved by using the gravity effect calculated from bathymetric information. Often the corresponding isostatic compensation is computed, and the combined bathymetric-isostatic gravity effect is used. However, the type and extent of compensation that exists in any particular region mostly remains unknown. Theoretical considerations indicate that the short wavelength part of the gravity field may be adequately modelled by the gravity effect of the bathymetry alone, without reference to an assumed compensation mechanism. With this in mind, a prediction scheme has been developed which utilises the short wavelength gravity field information implied by the bathymetry, combined with the long wavelength gravity field information from existing observed gravity. This scheme allows the prediction of ???fill-in??? gravity values in areas with limited observed gravity. The prediction technique was used on a test set of data off the east coast of Greenland. The prediction technique was seen to outperform a simple interpolation of gravity values by approximately ten percent. Geoid computations performed with the predicted gravity values indicate that the prediction technique can provide significant improvements in computed geoids.
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Hell, Benjamin. "Mapping bathymetry : From measurement to applications." Doctoral thesis, Stockholms universitet, Institutionen för geologiska vetenskaper, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-57291.
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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.<br><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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Peak, Scott Douglas. "Wave refraction over complex nearshore bathymetry." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Dec%5FPeak.pdf.
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de, Wet Willem Myburgh. "Bathymetry of the South African Continental Shelf." Master's thesis, University of Cape Town, 2013. http://hdl.handle.net/11427/28970.
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South Africa has an extensive coastline offshore of which lies the prominent South African
continental shelf, a relatively flat extension of the onshore coastal plain. The continental shelf is host to major mineral and petroleum deposits, home to South Africa’s major sea fisheries and full of
navigation hazards. Therefore, knowledge of the seafloor features, or bathymetry, of the continental
shelf is essential to understanding both its long-term geological evolution and present-day use for
resources and navigation. Unfortunately there has been little advancement in our knowledge of the
South African continental shelf since the marine studies of the 1970’s and 1980’s which culminated
in the “Bathymetry around Southern Africa” map of Dingle et al. (1987).
Although bathymetric mapping equipment and techniques have greatly improved during the last few decades, very little high resolution bathymetric data of the South African continental margin are
currently available for scientific use, with the majority of the high resolution multi-beam echo-sounding bathymetric surveys being undertaken by privately owned mineral exploration and mining
companies (such as De Beers, Alexkor, Petro SA, Petroleum Agency of South Africa, etc.), the Council for Geoscience and the South African Navy and Hydrographic Office. More recent advances in satellite altimetry have had a major impact on ocean floor bathymetric mapping especially in deep ocean areas where the sea surface generally reflects the underlying bathymetry.
The Department of Agriculture, Forestry and Fisheries (DAFF) annually collect single-beam echo-sounding data in order to monitor the abundance of fish species along the South African continental shelf and along with that collect seafloor bathymetry as an additional benefit. The aim of this project is to create a detailed bathymetric map of the continental shelf of South Africa by using digital single-beam echo-sounding data collected by the Fisheries Division of the DAFF over the last two decades. The bathymetric dataset of ±7 million single-beam echo-sounding data points was manually processed, gridded and exported to produce a detailed bathymetric map of the entire South African continental shelf between the Orange River mouth and Kosi Bay complemented by Satellite Altimetry data from the ETOPO 1 – 1 Arc-Minute Global Relief Model (Amante and Eakins 2009) for the deep ocean area adjacent to the continental shelf. The single- beam bathymetric data were collected by the F.R.S. Africana II and F.R.S. Algoa vessels using SIMRAD EKS-38, EK 400, EK 500 and more recently the EK 60 single-beam echo-sounders along with a the SIMRAD ES38B split beam transducer. The West Coast and South Coast margins have the greatest bathymetric detail due to DAFF’s Cape Town base of operations, whilst the East Coast margin is less detailed due to fewer research campaigns in this area.
The Bathymetric Map of the South African Continental Margin produced in this thesis reveals
several new and more detailed bathymetric features. New bathymetric features include the
northern extension of the Olifants Valley submarine canyon, details of the rocky inner shelf related
to glacial period sea level lowstands, as well as the coast parallel wave cut terraces and palaeo dune ridges on the middle shelf between Cape Seal and Cape Recife. Other prominent bathymetric
features such as Childs Bank, Cape Canyon, Cape Point Valley, the offshore submerged river valleys of the Breede and Gouritz Rivers and the east-west trending, basement anticlinal ridges situated at the southernmost extent of the Agulhas Arch were revealed in greater detail by this study. The underlying geology, physical Oceanography, drainage patterns as well as eustatic sea-level fluctuations can all be linked to the bathymetry of the continental shelf, which is why this thesis examines the influences of each of these factors on the seafloor morphology around the South African coastline.
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Lane, Dallas W. "Signal processing methods for airborne lidar bathymetry." Title page, table of contents and abstract only, 2001. http://web4.library.adelaide.edu.au/theses/09ENS/09ensl265.pdf.
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"August 2001." Includes bibliographical references (leaves 77-80). Examines the susceptibility of existing signal processing methods to errors and identifies other possible causes of depth error not accounted for by existing signal processing methods, by analysis of the detected laser return waveform data. Methods to improve depth accuracy are investigated.
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Beyer, Andreas. "Seafloor analysis bsed on multibeam bathymetry and backscatter data = Meeresbodenanalyse auf der Basis von Bathymetrie und akustischer Rückstreuung /." Bremerhaven : Alfred-Wegener-Institut für Polar- und Meeresforschung, 2006. http://www.loc.gov/catdir/toc/fy0711/2007403021.html.
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Beyer, Andreas. "Seafloor analysis based on multibeam bathymetry and backscatter data = Meeresbodenanalyse auf der Basis von Bathymetrie und akustischer Rückstreuung /." Bremerhaven : Alfred-Wegener-Inst. für Polar- und Meeresforschung, 2006. http://www.loc.gov/catdir/toc/fy0711/2007403021.html.
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Rodriguez-Ortiz, Claudia Doria. "Automated bathymetry mapping using an autonomous surface craft." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/39621.
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Jakobsson, Martin. "Mapping the Artic Ocean : bathymetry and Pleistoce paleoceanography /." Stockholm : Department of geology and geochemistry, Stockholm university, 2000. http://catalogue.bnf.fr/ark:/12148/cb409769608.
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Fisher, Thomas M. "Shallow water bathymetry at Lake Tahoe for AVIRIS data." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1999. http://edocs.nps.edu/npspubs/scholarly/theses/1999/Dec/99Dec%5FFisher.pdf.
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Thesis (M.S. in Physical Oceanography) Naval Postgraduate School, December 1999.<br>"December 1999". Thesis advisors(s): Richard Christopher Olsen, Pierre-Marie Poulain. Includes bibliographical references (p. 55-56). Also available online.
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Ruth, David M. "A nonlinear wave shoaling model for alongshore varying Bathymetry." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2001. http://handle.dtic.mil/100.2/ADA397402.
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Thesis (M.S. in Meteorology and Physical Oceanography)--Naval Postgraduate School, Sept. 2001.<br>Thesis advisor, Herbers, Thomas H.C. "September 2001." Includes bibliographical references (p. 47-48). Also available in print.
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Burroughes, Janet Eirlys. "The synthesis of estuarine bathymetry from sparse sounding data." Thesis, University of Plymouth, 2001. http://hdl.handle.net/10026.1/1887.
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The two aims of the project involved: 1. Devising a system for prediction o f areas of bathymetric change within the Fal estuary 2. Formulating and evaluating a method for interpolating single beam acoustic bathymetry to avoid artefacts o f interpolation. In order to address these aims, sources of bathymetric data for the Fal estuary were identified as Truro Harbour Office, Cornwall County Council and the Environment Agency. The data collected from these sources included red wavelength Lidar, aerial photography and single beam acoustic bathymetry from a number of different years. These data were input into a Geographic Information System (GIS) and assessed for suitability for the purposes o f data comparison and hence assessment of temporal trends in bathymetry within the estuary Problems encountered during mterpolation of the acoustic bathymetry resulted in the later aim of the project, to formulate an interpolation system suitable for interpolation of the single beam, bathymetric data in a realistic way, avoiding serious artefacts of interpolation. This aim was met, successfully, through the following processes: 1. An interpolation system was developed, using polygonal zones, bounded by channels and coastlines, to prevent interpolation across these boundaries. This system, based on Inverse Distance Weighting (IDW) interpolation, was referred to as Zoned Inverse Distance Weighting (ZIDW). 2. ZIDW was found, by visual inspection, to eliminate the interpolation artefacts described above. 3. The processes of identification of sounding lines and charmels, and the allocation of soundings and output grid cells to polygons, were successfully automated to allow ZIDW to be applied to large and multiple data sets. Manual intervention was maintained for processes performed most successfully by the human brain to optimise the results o f ZIDW. 4. To formalise the theory of ZIDW it was applied to a range of idealised, mathematically defined chaimels. For simple straight and regular curved, mathematical channels interpolation by the standard TIN method was found to perform as well as ZIDW. 5. Investigation of sinusoidal channels within a rectangular estuary, however, revealed that the TIN method begins to produce serious interpolation artefacts where sounding lines are not parallel to the centre lines o f channels and ridges. Hence, overall ZIDW was determined mathematically to represent the optimum method o f interpolation for single beam, bathymelric data. 6. Finally, ZIDW was refined, using data from the Humber and Gironde estuaries, to achieve universal applicability for interpolation of single beam, echo soimding data from any estuary. 7. The refinements involved allowance for non-continuous, flood and ebb type charmels; consideration of the effects of the scale of the estuary; smoothing of the channels using cubic splines; interpolation using a 'smart' ellipse and the option to reconstruct sounding lines from data that had previously been re-ordered.
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Colmenero, Jorge S. B. Massachusetts Institute of Technology. "Generation of high quality 2D meshes for given bathymetry." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/92669.
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Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (page 33).<br>This thesis develops and applies a procedure to generate high quality 2D meshes for any given ocean region with complex coastlines. The different criteria used in determining mesh element sizes for a given domain are discussed, especially sizing criteria that depend on local properties of the bathymetry and relevant dynamical scales. Two different smoothing techniques, Laplacian conditioning and targeted averaging, were applied to the fields involved in calculating the sizing matrix. The L² norm was used to quantify which technique had the greatest preservation of the original field. In both the reduced gradient and gradient cases, targeted averaging had a lower L² norm. The sizing matrices were used as inputs for two mesh generators, Distmesh and GMSH, and their meshing results were presented over a set of ocean domains in the Gulf of Maine and Massachusetts Bay region. Further research into the capabilities of each mesh generator are needed to provide a detailed evaluation. Mesh quality issues near coastlines revealed the need for small scale feature size recognition algorithms that could be implemented and studied in the future.<br>by Jorge Colmenero.<br>S.B.
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Yoder, Madonna K. "Lower Charles River bathymetry : 108 years of fresh water." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/114326.
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Thesis: S.B., Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2017.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (page 22).<br>The Lower Charles River has been a heavily utilized urban river that runs between Cambridge and Boston in Massachusetts. The recreational usage of the river is dependent on adequate water depths and there have been no definitive prior studies on the sedimentation rate of the Lower Charles River. The river transitioned from tidal to a freshwater basin in 1908 and the study area for historical comparisons was from the old Charles River Dam to the Boston University Bridge. This study surveyed the river, digitized three prior surveys that spanned 114 years, calculated volumes and depth distributions for each survey, and estimated sedimentation rates from fits to the volumes over time. The average sedimentation rate is estimated as 5-10 mm/year, which implies 1.8-3.5 feet sedimentation since 1908. Sedimentation rates and distributions are necessary to develop comprehensive management plans for the river.<br>by Madonna K. Yoder.<br>S.B.
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Hayden, Jesse Thomas. "Indian River Inlet Bridge and Bathymetry Scour Monitoring System." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 163 p, 2009. http://proquest.umi.com/pqdweb?did=1885754611&sid=2&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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Parkinson, Steven. "Modelling free-surface flow with bathymetry variation using spectral methods." Thesis, University of Bristol, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.570859.
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Generation of electricity, by harnessing tidal currents with turbines, has the potential to contribute to a more sustainable future. However, knowledge of the fluid velocity, at a certain depth, is required in order to predict the available energy resource. Therefore, a modelling framework is described, which is computationally efficient, with only a few tunable parameters, and yields good results in comparison to experimental work and computational fluid dynamics. Existing approximate analysis methods, which describe fluid flow over varying topography are discussed. It is found that these theories are incapable of satisfying our objective. From field measurements of a tidal channel, a model is developed that describes turbulent free-surface flow over varying bathymetry. The flow is modelled using the steady incompressible two- dimensional shallow water equations. Turbulence closure is achieved using the eddy-viscosity model. The equations are solved using spectral methods. Convergence of the method is tested by varying the number of modes and the mixing parameterisation. A comparison with experimental work and a regional scale ocean circulation model, for free-surface flow over a ridge, is made. Close agreement is found using pseudo spectral methods. The Galerkin method does not achieve the same level of accuracy. In addition, numerical instability is found to occur on the downstream face of the ridge. However, provided the bathymetry gradients are sufficiently shallow, the solution procedure performs well. A three-dimensional model is achieved by calculating the two-dimensional depth-averaged flow through a tidal channel. Upon calculation of the streamlines from the depth-averaged flow solution, the vertical structure of the flow is calculated. The full flow profile can be obtained by piecing together outputs from each streamline. This is then compared to a one-dimensional hydraulic model where good agreement is found. Finally, flow for a real channel is computed.
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Fricker, Paul David 1965. "The effect of stratification and bathymetry on internal seiche dynamics." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/80967.
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Holman, Kiyomi. "Testing Approaches and Sensors for Satellite-Derived Bathymetry in Nunavut." Thesis, Université d'Ottawa / University of Ottawa, 2020. http://hdl.handle.net/10393/41402.
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Nearshore bathymetry in the Canadian Arctic is poorly surveyed, but is vital knowledge for coastal communities that rely on marine transportation for resources and development. Nautical charts currently available are often outdated and surveying by traditional methods is both time consuming and expensive. Satellite-derived bathymetry (SDB) offers a significantly cheaper and faster option to provide information on nearshore bathymetry. The two most common approaches to SDB are empirical and physics-based. The empirical approach is simple and typically does well when calibrated with high-quality in-situ data, whereas the physics-based approach is more difficult to implement and requires precise atmospheric correction. This project tests the practical use of five methods within the empirical and physics-based approaches to SDB, using Landsat 8 and Sentinel-2 satellite imagery, at seven sites across Nunavut. Methods tested include: the Ratio-Transform, Multiband, and Random Forest Regression methods (empirical) and radiative transfer modeling (physics-based) using two atmospheric correction models: ACOLITE and Deep Water Correction. All methods typically use geolocated water depth data for validation, as well as calibration for the empirical methods. Spectral reflectance for model inputs were collected in Cambridge Bay, NU. Water depth data were acquired from the Canadian Hydrographic Service. All processing was conducted within the framework of plugins developed for the open-source GIS software, QGIS. Results from the empirical methods were typically poor due to poor calibration data, though Random Forest Regression performed well when good calibration data were available. Due to poor quality validation data, error for the physics-based results cannot be adequately quantified in most places. Additionally, atmospheric correction remains a challenge for the physics-based methods. Overall, results indicate that where large, high-quality calibration datasets are available, Random Forest Regression performs best of all methods tested, with little bias and low mean absolute error in water less than 10 m deep. As such datasets are rare in the Arctic, the physics-based method is often the only option for SDB and is an excellent qualitative tool for informing communities of shallow bathymetry features and assessing navigation risk.
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Bingley, Lemuel G. "A four receiver sidescan sonar for high definition swath bathymetry." Thesis, University of Sussex, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336058.
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Murphy, Judith A. "Entry of Weddell Sea Deep Water to the Argentine Basin : pathways and controls." Thesis, University of East Anglia, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389272.
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Stewart, Lewis. "Investigation of Sediment Ridges Using Bathymetry and Backscatter near Clearwater, Florida." Scholar Commons, 2017. http://scholarcommons.usf.edu/etd/7091.
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Changes in sediment morphology on the West Florida Shelf is investigated over a 14-year time period using multibeam bathymetry and backscatter in water depths between 10 m and 20 m, off the coast of Indian Rocks Beach, Pinellas County, Florida. Bathymetric surveys collected in 2002 (Kongsberg EM 3000 at 300 kHz) and 2016 (Reson 7125 at 400 kHz) were processed using CARIS Hips and Sips to create bathymetric maps and backscatter images. These data were then interpreted and compared in order to test hypotheses and answer questions related to sediment migration and sediment volume change.
The following questions prompted this study:
A. How mobile is the sediment on the limestone?
B. What sedimentary changes occurred following the 2002 and 2003 deployments of mines for an Office of Naval Research project?
C. How much sediment was removed during dredging and how closely does it compare to the Army Corps of Engineers’ reported estimate during the beach renourishment of Sand Key in 2012?
In order to answer these questions, hypotheses were proposed:
Hypothesis A:
The sediment ridges in the study site have not migrated significantly over the limestone hard bottom during the 14-year time period (Hafen, 2001; Edwards et al. 2003).
Hypothesis B:
There is no change in sediment volume where the mine-like object were placed and removed after the ONR mine burial experiment (Wolfson 2005 Wolfson et al. 2007).
Hypothesis C:
Changes in sediment volume between 2002 and 2016 will match the amount estimated by the Army Core of Engineers who dredged the area.
Results show that the sediment ridges in the study area had some migration over the limestone hard bottom during the 14-year time period. The results also found that there was a sediment volume change where mine-like objects were placed and removed during the Office of Naval Research mine burial experiment because of a dredging operation in 2012 that dredged sediment from the experimental area. Specific areas investigated that surround the dredging area showed significant loss of sediment, with the change in hydrodynamics from dredging influencing this sediment loss. The volume of sediment removed from the aforementioned dredging cut was found to be within 16% of that estimated in the Army Corps of Engineers report prior to the dredging.
Geologic interpretations of the backscatter images interpreted strong backscatter returns as limestone, mid strength returns as coarse shell hash and weak returns as fine to medium-grained sediments. The weak returns were found primarily on the sediment ridges. The dredging cut showed stronger returns than the surrounding ridge, indicating that underlying coarse sediments were most likely compacted and composed of shell hash.
Using satellite remote sensing as a way to gather continual repeat coverage at high resolution (2 m) data to determine absolute depth in these water depths is investigated and preliminary results suggest that processed 250 m pixel MERIS data will give a similar depth range as multibeam bathymetry. The higher-resolution 0.5 m pixel raw WorldView 2 data shows NW-SE trending structure, suggesting the seafloor morphology will be more visible.
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Tulldahl, Michael. "Detection and depth sounding of small targets with airborne laser bathymetry /." Linköping : Univ, 2003. http://www.bibl.liu.se/liupubl/disp/disp2003/tek855s.pdf.
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Becker, Joseph Jeffrey. "Improved global bathymetry, global sea floor roughness, and deep ocean mixing." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2008. http://wwwlib.umi.com/cr/ucsd/fullcit?p3296703.
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Thesis (Ph. D.)--University of California, San Diego, 2008.<br>Title from first page of PDF file (viewed March 18, 2008). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.
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McCarthy, Bradley L. "Coastal bathymetry using 8-color multispectral satellite observation of wave motion." Thesis, Monterey, California. Naval Postgraduate School, 2010. http://hdl.handle.net/10945/5199.
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Approved for public release; distribution is unlimited<br>Coastal bathymetry was measured using wave motion as observed by a commercial satellite imaging system. The linear finite depth dispersion relation for surface gravity waves was used to determine nearshore ocean depth from successive images acquired by the WorldView-2 satellite of the coastal area near Camp Pendleton, California. Principal component transforms were performed on co-registered images and principal component four was found to very effectively highlight wave crests in the surf zone. Change detection images, which included principal component four from successive images, contained both spatial and temporal information. From these change detection images, wave celerity could be determined and depth inversion could be performed. For waves farther from shore, principal component four no longer highlighted wave crests. Waves could be resolved within a single RGB composite image with equalization enhancement. The wavelength of a wave above a known depth was measured and the wave period method was used to determine depth for other waves in the propagation direction of this wave. Our depth calculations compared favorably to our reference bathymetry. The spatial resolution for this method of determining depth is higher and perhaps more accurate than our reference bathymetry, particularly in the surf zone.
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Pawlenko, Matthew. "Derivation of river bathymetry using imagery from unmanned aerial vehicles (UAV)." Thesis, Monterey, California. Naval Postgraduate School, 2011. http://hdl.handle.net/10945/5466.
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Approved for public release; distribution is unlimited.<br>In many places that U.S. forces operate, there exists an insufficient amount of data regarding river water depths, which is a necessity for safe operational planning. Satellite sensors and airborne manned platforms have been used for bathymetric derivation, but are not in abundance, nor do they have the spatial resolution required to examine smaller rivers. Using Unmanned Aerial Vehicles (UAV), this research examines the feasibility of using a ratio method with digital imagery to derive water depths, as well as a simpler polynomial regression to create a lookup table for use in the field. The results show that the ratio method of Red to Blue had higher correlation than Red color band on its own, and that the simple polynomial regression using a ratio of Red to Blue had higher correlation than more widely accepted methods. However, both methods are limited by a maximum depth, which is defined as the point where color no longer changes with depth. All depths beyond this point appear as this maximum depth. These findings show that using imagery from UAVs for bathymetric derivation could be a feasible alternative to accepted satellite imagery methods, but further research is needed to demonstrate operational utility.
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Mancini, Steven. "Automating Nearshore Bathymetry Extraction from Wave Motion in Satellite Optical Imagery." Thesis, Monterey, California. Naval Postgraduate School, 2012. http://hdl.handle.net/10945/6826.
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Nearshore depths for Waimanalo Beach, HI, are extracted from optical imagery, taken by the WorldView-2 satellite on 31 March 2011, by means of automated wave kinematics bathymetry (WKB). Two sets of three sequential images taken at intervals of about 10 seconds are used for the analyses herein. Water depths are calculated using a computer program that registers the images, estimates the currents, and then uses the linear dispersion relationship for surface gravity waves to estimate depth. Depths are generated from close to shore out to about 20 meters depth. Comparisons with SHOALS LIDAR bathymetry values show WKB depths are accurate to about half a meter, with R2 values of 90%, and are frequently in the range of 1020 percent relative error for depths ranging from 216 meters.
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Siqueira, Sunni A. "Effect of Small-Scale Continental Shelf Bathymetry on Storm Surge Generation." ScholarWorks@UNO, 2016. http://scholarworks.uno.edu/td/2278.
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Idealized bathymetries were subjected to idealized cyclones in order to measure the storm surge response to a range of bathymetry features, under various storm conditions. Ten bathymetries were considered, including eight shoals, one pit, and a featureless reference domain. Six storms (two different sizes/intensities and three different landfall directions) were used as meteorological forcing. The bathymetry features influenced local surge response during pre- and post-peak surge conditions. However, peak surge and surge at the coast were not meaningfully affected by the presence of the bathymetry features considered. The effect of three bathymetry feature parameters on surge response was analyzed (i.e. depth below mean sea level, cross-shore width, and distance from shore). Of these parameters, feature depth below mean sea level was the most influential on surge generation.
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Zhang, Zitao. "Machine Learning for Inferring Sidescan Images from Bathymetry and AUV Pose." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-254947.
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Underwater navigation has been a big challenge for autonomous underwater vehicles (AUVs) for a long time. It is highly dependent on acoustic methods called SONAR. There are two kinds of sonar sensors which are commonly used, the multibeam sonar and the sidescan sonar. Both of them have some advantages and limitations. Substantial improvements can be made if a machine interpretation method can be developed for the translation between these two sonar data.The objective of this thesis project is to find an effective way to do translation from seabed bathymetry (underwater depth) data (from multibeam sonar) to sidescan sonar images. In the project, we explored the feasibility of machine learning based translation methods. Some different generative models based on the idea of generative adversarial nets were tried. This project is an experimental trial, and it still needs more improvement before production. But the result shows a strong potential for the ability of machine learning based methods to handle this kind of translation tasks.<br>Navigeringen har varit en stor utmaning för autonoma undervattensfordon (AUV) under lång tid. Typiskt används akustiska metoder, så kallad SONAR. Det finns två typer av sonarsensorer, multibeam sonar och sidescan sonar. Båda har styrkor och svagheter. Genom att översätta mellan dessa två sensordata kan betydande förbättringar uppnås.Syftet med detta avhandlingsprojekt är att hitta ett effektivt sätt för att översätta data från batymetri (undervattensdjup, från multibeam sonar) till sidescan sonarbilder. I projektet undersökte vi genomförbarheten för översättningsmetoder baserad på maskininlärning. Olika generativa modeller baserade på generative adversarial nets (GANs) hade undersöktes. Detta projekt kan ses som en förstudie. Ytterligare förbättringar krävs fortfarande, men resultatet visar en stark potential för maskininlärningsmetoder att hantera denna typ av översättningsuppgifter.
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Corner, Robert J. "Passive spectral bathymetry using satellite remote sensing in Cockburn Sound, W.A." Thesis, Curtin University, 1992. http://hdl.handle.net/20.500.11937/2571.
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Conventional bathymetric surveying is a costly and time consuming business. Even today many areas of shallow inshore ocean, some which encompass potential oil and gas fields, are only minimally charted. There is a need for reconnaissance systems which can effectively direct more expensive detailed surveys to best effect. Remote spectral bathymetry is one such system.A review of candidate sensor systems and processing algorithms highlighted problems due to changing bottom cover types and water quality parameters. A method, proposed and theoretically validated by other workers, was chosen for further investigation. This method develops an approximate relationship between the spectral content of the satellite data and water depths and then, by an iterative phase in the spatial domain, seeks to minimise the effect of spatially dependant variations.A study site in Cockburn Sound, Western Australia was chosen for a demonstration of this method. Spectral data are from the Landsat Thematic Mapper instrument and depth data are taken from Admiralty Charts. A variation on the originally proposed algorithm introduces spatial preprocessing phase, in which the image is segmented into zones where spectral relationships are expected to be more uniform. Two different methods of spatial mapping are used.The results demonstrate the capability of spatial modelling to improve remotely sensed depth estimates in the depth range of 5 to 12 m. The need for further research to better understand the shallow water spectral relationships is identified.
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Corner, Robert J. "Passive spectral bathymetry using satellite remote sensing in Cockburn Sound, W.A." Curtin University of Technology, School of Surveying and Mapping, 1992. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=10329.
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Conventional bathymetric surveying is a costly and time consuming business. Even today many areas of shallow inshore ocean, some which encompass potential oil and gas fields, are only minimally charted. There is a need for reconnaissance systems which can effectively direct more expensive detailed surveys to best effect. Remote spectral bathymetry is one such system.A review of candidate sensor systems and processing algorithms highlighted problems due to changing bottom cover types and water quality parameters. A method, proposed and theoretically validated by other workers, was chosen for further investigation. This method develops an approximate relationship between the spectral content of the satellite data and water depths and then, by an iterative phase in the spatial domain, seeks to minimise the effect of spatially dependant variations.A study site in Cockburn Sound, Western Australia was chosen for a demonstration of this method. Spectral data are from the Landsat Thematic Mapper instrument and depth data are taken from Admiralty Charts. A variation on the originally proposed algorithm introduces spatial preprocessing phase, in which the image is segmented into zones where spectral relationships are expected to be more uniform. Two different methods of spatial mapping are used.The results demonstrate the capability of spatial modelling to improve remotely sensed depth estimates in the depth range of 5 to 12 m. The need for further research to better understand the shallow water spectral relationships is identified.
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Yoo, Jeseon. "Nonlinear Bathymetry Inversion Based on Wave Property Estimation from Nearshore Video Imagery." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/19793.
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Video based remote sensing techniques are well suited to collect spatially resolved wave images in the surf zone with breaking waves and dynamic bathymetric changes. An advanced video-based depth inversion method is developed to remotely survey bathymetry in the surf zone. The present method involves image processing of original wave image sequences, wave property estimation based on linear feature extraction from the processed image sequences, and is combined with a nonlinear depth inversion model. The original wave image sequences are processed through video image frame differencing and directional low-pass filtering schemes to remove wave-breaking-induced foam noise having high frequencies in the surf zone. The features of individual crest trajectories are extracted from the processed and rectified image sequences, i.e. processed image cross-shore timestacks, by tracking pixels of high intensity within an interrogation window of a Radon-transform-based line-detection algorithm. The wave celerity is computed using space-time information of the extracted trajectories of individual wave crests in the cross-shore timestack domain. The presented retrieval of nearshore bathymetry from video image sequences is based on a nonlinear depth inversion using the nonlinear shallow water wave theory. The nonlinear wave amplitude dispersion effects at the breaker points are determined by combining the nonlinear shallow water celerity equation with a wave breaker criterion, thereby computing water depths iteratively from the celerity measured from the video data. The water depths estimated at the breaker points present initial bathymetric anchor points. Bathymetric profiles in the surf zone are inverted by calculating wave heights dissipated after wave breaking with a wave dissipation model and wave heights shoaled before wave breaking with a wave shoaling model. The continuous wave amplitude dispersion effects are subtracted from the measured celerity profiles, resulting in nearshore bathymetric profiles. The nonlinear depth inversion derived bathymetric estimates from nearshore imagery match the measured values with a biased mean depth error of about +0.06m in the depth range of 0.1 to 3m. In addition, the wave height estimates by the depth inversion model are comparable to the in-situ measured wave heights with a biased mean wave height error of about +0.14m. The present depth inversion method based on optical remote-sensing supports coastal management, navigation, and amphibious operations.
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Kaawan, Abdelkadir Omar. "A study of the rift system over north-west libya using geophysical and remote sensing data." Thesis, University of Newcastle Upon Tyne, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.265435.
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Cousins, David Bruce. "A model-based algorithm for environmentally adaptive bathymetry and sound velocity profile estimation /." View online ; access limited to URI, 2005. http://0-wwlib.umi.com.helin.uri.edu/dissertations/dlnow/3186901.
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Carr, Domenic Anthony. "A study of the target detection capabilities of an airborne lidar bathymetry system." Thesis, Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/47585.
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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.
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Myrick, Kenneth B. "Coastal bathymetry using satellite observation in support of intelligence preparation of the environment." Thesis, Monterey, California. Naval Postgraduate School, 2011. http://hdl.handle.net/10945/5519.
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Approved for public release; distribution is unlimited.<br>Subaqueous beach profiles are obtained for littoral regions near Camp Pendleton, CA, using observations of wave motion. Imagery was acquired from WorldView2 Satellite on 24 March 2010. Two sequential images taken 10 seconds apart are used for the analyses herein. Water depths were calculated using linear dispersion relationship for surface gravity waves. Depth profiles were established from shoreline out to 1 kilometer offshore and depths of up to 15 meters. Comparisons with USGS DEM values show agreement within five percent in the surf zone (shoreline to wave breaking) and one percent outside the surf zone (offshore of wave breaking).
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Cooper, Christopher James. "Anomalous bathymetry and mass heterogeneity at the conjugate Iberia and Newfoundland rifted margins." Thesis, University of Liverpool, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.539715.
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Horna, Munoz Daniel Vicente. "Investigation of floodwave propagation over natural bathymetry using a three-dimensional numerical model." Diss., University of Iowa, 2017. https://ir.uiowa.edu/etd/5948.
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The current standard of simulating flood flow in natural river reaches is based on solving the 1-D or 2-D St. Venant equations or using hybrid 1-D/2-D models based on the same equations. These models are not always able to accurately predict floodwave propagation, especially around and downstream of regions where 3-D effects become important, or at times when the main assumptions associated with these models are violated (e.g. flow becomes pressurized due to presence of a hydraulic structure like a bridge or a culvert). A 3-D modeling approach, though computationally much more expensive, is not subject to such limitations and should be able to predict accurately predict floodwave propagation even in regions where 3-D effects are expected to be significant. This dissertation describes the development and validation of a 3-D time-accurate RANS-based model to study flood-related problems in natural environments. It also discusses how results from these 3-D simulations can be used to better calibrate lower order models. Applications are included where the flow becomes pressurized during high flow conditions and the sediment entrainment potential of the flow during the flooding event is estimated. Another important category of applications discussed in the present study are floodwave propagation induced by a sudden dam break failure. Results show that 2-D models show fairly large differences with 3-D model predictions especially in regions where 3-D effects are expected to be significant (e.g. near channel-floodplain transition, in highly curved channels, near hydraulic structures). The study also discusses the use of the validated 3-D model as an engineering design tool to identify the optimum solution for flood protection measures intended to reduce flooding in the Iowa River near Iowa City. 3-D simulation results are also used to discuss hysteresis effects in the relationship between bed shear stress and the stage/discharge. Such effects need to be taken into consideration to accurately estimate erosion associated with the passage of a floodwave.
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Kubisak, Timothy D. "Investigation of acoustic vector sensor data processing in the presence of highly variable bathymetry." Thesis, Monterey, California: Naval Postgraduate School, 2014. http://hdl.handle.net/10945/42664.
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Approved for public release; distribution is unlimited<br>Data has been collected on acoustic vector sensors mounted on autonomous underwater gliders in the Monterey Bay during 2012–2013. Previous processing work computed the acoustic vector intensity to estimate bearing to impulsive sources of interest. These sources included small explosive shots deployed by local fishermen and humpback whale vocalizations. While the highly impulsive shot data produced unambiguous bearing estimations, the longer duration whale vocalizations showed a fairly wide spread in bearing. In this work, causes of the ambiguity in bearing estimation are investigated in the context of the highly variable bathymetry of the Monterey Bay Canyon, as well as the coherent multipath interference in the longer duration calls. Sound speed data collected during the previous experimental effort, along with a three-dimensional bathymetric relief of the Monterey Bay Canyon, are incorporated into a three-dimensional version of the Monterey-Miami Parabolic Equation Model. Propagation results are computed over a frequency band from 336–464 Hz in order to provide predictions of pulse arrival structure. This data is analyzed using conventional pressure plane-wave beamforming techniques in order to highlight horizontal coupling caused by the canyon bathymetry. The data is also analyzed using the previously developed acoustic vector intensity processing string and shown to exhibit a qualitatively similar spread in the estimated bearing.
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Strauss, Darrell Richard. "Morphological Modelling of Intermediate Beach State Transitions." Thesis, Griffith University, 2010. http://hdl.handle.net/10072/367253.
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Temporal and spatial changes in nearshore bathymetry result from sediment transport interactions with the hydrodynamic processes and provide a highly variable and rapidly changing environment. Rip currents are one example of a morphody- namic system presenting a significant hazard to swimmers unfamiliar with their behaviour. Rip currents pose a particular threat as they can develop suddenly and quickly transport water offshore.
The widely accepted beach state model of Wright & Short (1984) uses param- eters which are functions of breaking wave height, wave period and sediment (Dean 1973, Gourlay 1968, Guza & Inman 1975) to classify the beach environment into distinct morphological states. These states range from reflective through inter- mediate to dissipative.
Breaking wave type is influenced by the bathymetry as the wave approaches breaking point within the surf-zone and can be classified by the the Iribarren num- ber or surf-similarity parameter (Battjes 1974). Intermediate beach states can be more difficult to assess with these parameters and may even consist of a combination of outer dissipative and inner locally reflective zones.<br>Thesis (PhD Doctorate)<br>Doctor of Philosophy (PhD)<br>Griffith School of Environment<br>Science, Environment, Engineering and Technology<br>Full Text
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Koeneke, Roberto. "Spatial Characterization of Puerto Rican Commercial Fisheries: Gear Usage Across Habitat Classes and Bathymetry Ranges." Scholarly Repository, 2011. http://scholarlyrepository.miami.edu/oa_theses/251.
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The spatial characterization of Puerto Rican commercial fisheries describing fishing gear use in relation to habitat classes and bathymetry ranges was achieved through the collection and analysis of spatial fisheries data. An extensive field data gathering session was conducted in the entire Puerto Rican territory during the summer months of 2009, from June to October. The field data was digitized and analyzed using geographic information systems (GIS) and computer spreadsheet software, and gear usage charts and graphs, fishing grounds maps, and fishing intensity maps were produced for four gear categories: line, net, dive, and trap gears. Patterns and evidence of likely relationships linking gear usage and benthic habitat, and between gear utilization and water depth ranges, were presented. The importance of the spatial characterization of the commercial fishery for Puerto Rican fisheries management, and other recommendations were given within the concluding chapter.
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Liu, Ya Nan. "Effect of variable bathymetry on the linear anf slow-drift wave responses of floating bodies." Aix-Marseille 1, 2010. http://www.theses.fr/2010AIX11006.
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Le problème considéré dans ce mémoire a trait au comportement sur houle irrégulière des structures flottantes opérant en relativement faible profondeur d’eau. Une situation de référence est un terminal méthanier, où les navires viennent se charger ou décharger de GNL (Gaz Naturel Liquéfié). La consommation mondiale de gaz étant en augmentation constante, et les pays producteurs éloignés des pays consommateurs, le transport de GNL par navires méthaniers est en forte croissance. De plus en plus fréquemment, faute d’espace et pour des raisons de sécurité, les terminaux ne sont plus en zone portuaire mais déportés au large, en mer ouverte, dans des profondeurs d’eau de 15 à 30 mètres. Les systèmes d’amarrage des navires doivent suffisamment restreindre leur mouvement pour permettre leur (dé)chargement, même pour des états de mer de quelques mètres de hauteur significative. Typiquement les périodes propres des mouvements horizontaux des méthaniers amarrés se situent entre 30 et 100 secondes : ceci signifie que non seulement leur réponse linéaire à la houle mais aussi leur réponse dite de ”deuxième ordre à basse fréquence” doit être correctement prédite dans le dimensionnement du système d’amarrage (aussi ères, ducs d’Albe, etc. ). L’industrie pétrolière offshore a maintenant acquis un grand savoir-faire dans le dimensionnement des systèmes d’ancrage en grande profondeur, pour ses unités de forage et de production. Il est rapidement apparu que les outils numériques développés pour ces applications n’étaient pas transposables au cas des terminaux méthaniers en zone côtière. En particulier des écarts importants ont été observés entre les prédictions des modèles numériques et les mesures faites en bassin d’essais, sur le comportement basse fréquence (aux fréquences propres du mouvement horizontal) du navire amarré. La raison la plus souvent invoquée de ces écarts est associée à la bathymétrie : la houle incidente évolue depuis le large sur des fonds variables, en profondeur d´ecroissante. Les variations bathymétriques sont le plus souvent lentes, avec des pentes de l’ordre du pour mille ou du pour cent, si bien qu’en première approximation les modèles classiques dits de faible pente prédisent correctement l’évolution de la houle ; mais cela n’est pas vrai de son contenu basse fréquence qui, localement, n’est pas le même que celui prédit par les théories de référence qui supposent une profondeur constante depuis l’infini. Il y a aussi des situations où le fond marin ne peut pas être considéré de faible pente, par exemple consécutivement à des opérations de dragage. Un cas de référence est le départ, depuis la côte, d’un pipeline o`u il s’avère souvent nécessaire de draguer un chenal pour que la barge de pose puisse opérer. Typiquement le chenal va avoir une profondeur de 10 à 15 mètres avec des fonds environnants beaucoup plus faibles. Là aussi des outils fiables sont necessaires pour prédire la réponse à la houle de la barge, dimensionner son ancrage, et vérifier que les contraintes dans le pipe sont admissibles. Le travail de thèse effectué ambitionne de faire avancer la connaissance sur ces problèmes de tenue à la houle de structures ancrées en bathymétrie variable, et de contribuer à l’amélioration des outils de dimensionnement.
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Su, Haibin. "Derivation of Coastal Bathymetry and Stream Habitat Attributes Using Remote Sensing Images and Airborne LiDAR." University of Cincinnati / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1313688135.
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Lee, Mark. "Benthic mapping of coastal waters using data fusion of hyperspectral imagery and airborne laser bathymetry." [Gainesville, Fla.] : University of Florida, 2003. http://purl.fcla.edu/fcla/etd/UFE0000730.
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Bisgard, Charlie. "Breaking and non-breaking solitary wave impact pressures on a cylinder over a 3-D bathymetry." Thesis, (4 MB), 2005. http://edocs.nps.edu/AR/topic/theses/2005/Jan/05Jan_Bisgard.pdf.
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Thesis (M.S.Civil and Environmental Engineering and Construction Management)--Oregon State University, 2005.<br>"January 2005." Description based on title screen as viewed on June 1, 2010 DTIC Descriptor(s): Three Dimensional, Bathymetry, Tsunamis, Earthquakes, Coastal Regions, Ocean Waves, Inertia, Landslides, Gravitational Fields, Seafloor Spreading, Long Wavelengths, Models, Energy, Theses, Time Includes bibliographical references (p. 84-85). Also available in print.
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Wang, Qing. "FINITE ELEMENT MODELING OF TIDES AND CURRENTS OF THE PASCAGOULA RIVER." Master's thesis, University of Central Florida, 2008. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3187.
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This thesis focuses on the simulation of astronomic tides of the Pascagoula River. The work is comprised of five steps: 1) Production of a digital elevation model describing the entire Pascagoula River system; 2) Development of an inlet-based, unstructured mesh for inbank flow to better understand the basis of the hydrodynamics within the Pascagoula riverine system. In order to assist in the mesh development, a toolbox was constructed to implement one-dimensional river cross sections into the two-dimensional model; 3) Implementation of a sensitivity analysis of the Pascagoula River two inlet system to examine the inlet effects on tidal propagation; 4) Improvement of the inlet-based model by performing a preliminary assessment of a spatially varied bottom friction; 5) Implementation of an advection analysis to reveal its influence on the flow velocity and water elevation within the domain. The hydrodynamic model employed for calculating tides is ADCIRC-2DDI (ADvanced CIRCulation Model for Shelves, Coasts and Estuaries, Two-Dimensional Depth Integrated). This finite element based model solves the shallow water equations in their full nonlinear form. Boundary conditions including water surface elevation at the off-shore boundary and tidal potential terms allow the full simulation of astronomic tides. The improved astronomic tide model showed strong agreement with the historical data at seven water level monitoring gauge stations. The main conclusions of this research are: 1) The western inlet of the Pascagoula River is more dominant than the eastern inlet; however, it is necessary to include both inlets in the model. 2) Although advection plays a significant role in velocity simulation, water elevations are insensitive to advection. 3) The astronomic model is sensitive to bottom friction (both global and spatial variations); therefore, a spatially varied bottom friction coefficient is suggested. As a result of this successful effort to produce an astronomic tide model of the Pascagoula River, a comprehensive storm surge model can be developed. With the addition of inundation areas the surge model can be expected to accurately predict storm tides generated by hurricanes along the Gulf Coast.<br>M.S.<br>Department of Civil and Environmental Engineering<br>Engineering and Computer Science<br>Civil Engineering MS
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Fabre, David H. "Parameterized Spectral Bathymetric Roughness Using the Nonequispaced Fast Fourier Transform." ScholarWorks@UNO, 2015. http://scholarworks.uno.edu/td/2070.
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The ocean and acoustic modeling community has specifically asked for roughness from bathymetry. An effort has been undertaken to provide what can be thought of as the high frequency content of bathymetry. By contrast, the low frequency content of bathymetry is the set of contours. The two-dimensional amplitude spectrum calculated with the nonequispaced fast Fourier transform (Kunis, 2006) is exploited as the statistic to provide several parameters of roughness following the method of Fox (1996). When an area is uniformly rough, it is termed isotropically rough. When an area exhibits lineation effects (like in a trough or a ridge line in the bathymetry), the term anisotropically rough is used. A predominant spatial azimuth of lineation summarizes anisotropic roughness. The power law model fit produces a roll-off parameter that also provides insight into the roughness of the area. These four parameters give rise to several derived parameters.
Algorithmic accomplishments include reviving Fox’s method (1985, 1996) and improving the method with the possibly geophysically more appropriate nonequispaced fast Fourier transform. A new composite parameter, simply the overall integral length of the nonlinear parameterizing function, is used to make within-dataset comparisons.
A synthetic dataset and six multibeam datasets covering practically all depth regimes have been analyzed with the tools that have been developed.
Data specific contributions include possibly discovering an aspect ratio isotropic cutoff level (less than 1.2), showing a range of spectral fall-off values between about -0.5 for a sandy- bottomed Gulf of Mexico area, to about -1.8 for a coral reef area just outside of the Saipan harbor. We also rank the targeted type of dataset, the best resolution gridded datasets, from smoothest to roughest using a factor based on the kernel dimensions, a percentage from the windowing operation, all multiplied by the overall integration length.