View All Items
(21 - 28 of 28)
Pages
- Title
- Calibration and Performance Evaluation for a Multiple Overlapping Field of View Serial Laser Imager.
- Creator
- Rasoletti, Nicholas, Beaujean, Pierre-Philippe, Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The Combined Laser and Scan Sonar (CLASS) system is an extended range imaging system, incorporating both high-resolution laser images and high frequency sonar images. Both the laser and sonar images are collected simultaneously during testing to provide dual mode imagery of an underwater target, displaying both a 2D image of the target (laser image) and a 3D overlay of the target (sonar image). The laser component of the system is a Multiple Overlapping Field of view Serial Laser Imager ...
Show moreThe Combined Laser and Scan Sonar (CLASS) system is an extended range imaging system, incorporating both high-resolution laser images and high frequency sonar images. Both the laser and sonar images are collected simultaneously during testing to provide dual mode imagery of an underwater target, displaying both a 2D image of the target (laser image) and a 3D overlay of the target (sonar image). The laser component of the system is a Multiple Overlapping Field of view Serial Laser Imager (MOFSLI), capable of generating high-resolution sub-centimeter 2D images. MOFSLI generates the images by way of a near diffraction-limited 532 [nm] continuous wave (CW) laser beam being scanned over the target. Initial field tests resulted in high-quality images of the ocean floor, but also indicated the need for additional research on MOFSLI. In this thesis, we focus on the calibration of MOFSLI and on the evaluation of the image quality generated by this system, as a function of range, source power, receiver gain and water turbidity. This work was completed in the specialized underwater electrooptics testing facility located in the Ocean Visibility and Optics laboratory at Harbor Branch Oceanographic Institute (HBOI). Laboratory testing revealed the operational limits of the system, which functioned well until just beyond five attenuation lengths, where it becomes contrast limited due attenuation of target signal and the collection of non-image bearing backscattered photons. Testing also revealed the optimal settings of the system at given environmental conditions.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00004538, http://purl.flvc.org/fau/fd/FA00004538
- Subject Headings
- Electrooptics, Inertial navigation systems, Lasers -- Measurement -- Evaluation, Light -- Scattering
- Format
- Document (PDF)
- Title
- Synchronization of coupled semiconductor lasers.
- Creator
- London, Michael S., Charles E. Schmidt College of Science, Department of Physics
- Abstract/Description
-
The synchronization of coupled semiconductor lasers with delay is investigated by numerical simulations of the nonlinear dynamic models complemented by a stability analysis of the linearized system. The equations used in the dissertation are based on the well known "Lang-Kobayashi" model modified to include unidirectional and bidirectional coupling. Stability diagrams are calculated and supplemented by numerically integrated time series. Synchronization is determined and quantified by...
Show moreThe synchronization of coupled semiconductor lasers with delay is investigated by numerical simulations of the nonlinear dynamic models complemented by a stability analysis of the linearized system. The equations used in the dissertation are based on the well known "Lang-Kobayashi" model modified to include unidirectional and bidirectional coupling. Stability diagrams are calculated and supplemented by numerically integrated time series. Synchronization is determined and quantified by computing the cross-correlation function. It is found that synchronized states are achievable for a wide range of coupling constants and delay times. These findings have implications for experiment and technological applications, notably in cryptography.
Show less - Date Issued
- 2011
- PURL
- http://purl.flvc.org/FAU/3318673
- Subject Headings
- Semiconductor lasers, Optical bistability, Nonlinear theories, Diodes, Semiconductor, Mathematical models
- Format
- Document (PDF)
- Title
- A new method to achieve lithic use-wear discrimination using laser scanning confocal microscopy.
- Creator
- Farber, Elliott, Dorothy F. Schmidt College of Arts and Letters, Department of Anthropology
- Abstract/Description
-
My study sought to acquire quantitative data from the surface of lithic tools and use that data to discriminate tools used on different contact materials. An experimental archaeological wear production method was conceived, whereby I and several volunteers produced wear on chert, heat-treated chert, and obsidian flakes by using those flakes on several contact materials. The flakes were then analyzed using a laser scanning confocal microscope, which recorded three-dimensional surface data from...
Show moreMy study sought to acquire quantitative data from the surface of lithic tools and use that data to discriminate tools used on different contact materials. An experimental archaeological wear production method was conceived, whereby I and several volunteers produced wear on chert, heat-treated chert, and obsidian flakes by using those flakes on several contact materials. The flakes were then analyzed using a laser scanning confocal microscope, which recorded three-dimensional surface data from each tool. The data was analyzed using cluster analysis to find the ideal combination of parameters which correctly discriminated the flakes based on use-wear data. After finding acceptable parameters which grouped flakes appropriately through cluster analysis, those groups were subjected to a discriminant analysis. Each analysis returned a p-value under .05, meaning that the clustering based on the parameters Sq and Sfd produced by the cluster analysis was not random, but indicative of these variables' ability to discriminate lithic use-wear. The major advantage of the approach developed in this study is that it can quantitatively discriminate use-wear produced by different contact materials on flakes with no a priori information at all.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fcla/dt/3362342
- Subject Headings
- Archaeology, Methodology, Archaeological surveying, Laser use in, Topographical surveying, Laser use in, Nanostructured materials, Tools, Prehistoric, Analysis
- Format
- Document (PDF)
- Title
- Developments in laser-line scanned undersea surface mapping and image analysis systems for scientific applications.
- Creator
- Caimi, F. M., Kocak, D. M., Asper, V. L., Harbor Branch Oceanographic Institute
- Date Issued
- 1996
- PURL
- http://purl.flvc.org/FCLA/DT/3183695
- Subject Headings
- Underwater imaging systems, Image analysis, Topographical surveying--Laser use in
- Format
- Document (PDF)
- Title
- Efficient laser pulse dispersion codes for turbid undersea imaging and communications applications.
- Creator
- Dalgleish, Fraser R., Caimi, F. M., Vuorenkoski, Anni K., Britton, W. B., Ramos, Brian, Giddings, T. E., Shirron, J. J., Mazel, C. H.
- Date Issued
- 2010
- PURL
- http://purl.flvc.org/FCLA/DT/3340792
- Subject Headings
- Underwater imaging systems, Laser communication systems, Radiative transfer, Monte Carlo method
- Format
- Document (PDF)
- Title
- A 3-D laser line scanner for outcrop scale studies of seafloor features.
- Creator
- Kocak, D. M., Caimi, F. M., Das, Partha S., Karson, J. A., Harbor Branch Oceanographic Institute
- Date Issued
- 1999
- PURL
- http://purl.flvc.org/FCLA/DT/3351977
- Subject Headings
- Scanning systems, Cartography--Laser use in, Geological maps, Submersibles, Ocean bottom--Maps
- Format
- Document (PDF)
- Title
- 3D Reconstruction of Simulated Bridge Pier Local Scour Using Green Laser and HydroLite Sonar.
- Creator
- Banyhany, Musab, Arockiasamy, Madasamy, Florida Atlantic University, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
Scour is the process of sediment erosion around bridge piers and abutments due to natural and man-made hydraulic activities. Excessive scour is a critical problem that is typically handled by enforcing design requirements that make the submerged structures more resilient. The purpose of this research is to demonstrate the feasibilities of the Optical- Based Green Laser Scanner and HydroLite Sonar in a laboratory setting to capture the 3D profile of simulated local scour holes. The Green Laser...
Show moreScour is the process of sediment erosion around bridge piers and abutments due to natural and man-made hydraulic activities. Excessive scour is a critical problem that is typically handled by enforcing design requirements that make the submerged structures more resilient. The purpose of this research is to demonstrate the feasibilities of the Optical- Based Green Laser Scanner and HydroLite Sonar in a laboratory setting to capture the 3D profile of simulated local scour holes. The Green Laser had successfully reconstructed a 3D point-cloud imaging of scour profiles under both dry and clear water conditions. The derived scour topography after applying water refraction correction was compared with the simulated scour hole, and was within 1% of the design dimensions. The elevations at the top and bottom surfaces of the 6.5-inch scour hole were -46.6 and -53.11 inches from the reference line at the origin (0,0,0) of the laser scanner. The HydroLite Sonar recorded hydrographical survey points of the scour’s interior surface. The survey points were then processed using MATLAB to obtain a 3D mesh triangulation.
Show less - Date Issued
- 2018
- PURL
- http://purl.flvc.org/fau/fd/FA00005995
- Subject Headings
- Scour at bridges, Sonar, Lasers, Scour at bridges--Evaluation--Technique
- Format
- Document (PDF)
- Title
- Mathematical modeling of wave-current interactions in marine current turbines.
- Creator
- Singh, Amit J., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
The concept of marine current turbines was developed by Peter Fraenkel in the early 1970s. Ever since Fraenkel's efforts to modify and test the technology, several worldwide agencies have been exploiting the technology to retrofit the marine current turbine to their particular application. The marine current turbine has evolved from generating a few kilowatts to a few gigawatts. The present study focuses on a megawatt sized turbine to be located offshore the coast of Ft. Lauderdale, Florida....
Show moreThe concept of marine current turbines was developed by Peter Fraenkel in the early 1970s. Ever since Fraenkel's efforts to modify and test the technology, several worldwide agencies have been exploiting the technology to retrofit the marine current turbine to their particular application. The marine current turbine has evolved from generating a few kilowatts to a few gigawatts. The present study focuses on a megawatt sized turbine to be located offshore the coast of Ft. Lauderdale, Florida. The turbine is to be placed in a similar location as a 20 kW test turbine developed by the Southeast National Marine Renewable Energy Center (SNMREC) at Florida Atlantic University, Dania Beach, FL. Data obtained from the SNMREC is used in the mathematical model. ANSYS FLUENT is chosen as the CFD software to perform wave-current interaction simulation for the present study. The turbine is modeled in SolidWorks, then meshed in ANSYS ICEM CFD, then run in FLUENT. The results obtained are compared to published work by scholarly articles from Fraenkel, Barltrop and many other well known marine energy researchers. The effects of wave height on the turbine operation are analyzed and the results are presented in the form of plots for tip speed ratio and current velocity.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3352832
- Subject Headings
- Wave resistance (Thermodynamics), Structural design, Mathematical models, Laser Doppler velocimetry, Marine turbines, Mathematical models
- Format
- Document (PDF)
