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An Investigation into the Acoustic Variability and the Attenuation of an Acoustic Signal within a Port Environment Focusing on Port Everglades, Florida
Title
An Investigation into the Acoustic Variability and the Attenuation of an Acoustic Signal within a Port Environment Focusing on Port Everglades, Florida.
Creator
Sheahan, Daniel, Frisk, George V., Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
A methodology for characterizing the acoustical properties of a port environment, namely Port Everglades, has been proposed and carried out. This approach includes both a port-wide analysis of how the basic oceanographic features within the port impact the acoustic properties, and also a more focused sampling methodology within a small region of Port Everglades, allowing for the acoustic characteristics, including ambient noise, and an approximate signal absorption to be computed. The results...
Show moreA methodology for characterizing the acoustical properties of a port environment, namely Port Everglades, has been proposed and carried out. This approach includes both a port-wide analysis of how the basic oceanographic features within the port impact the acoustic properties, and also a more focused sampling methodology within a small region of Port Everglades, allowing for the acoustic characteristics, including ambient noise, and an approximate signal absorption to be computed. The results documented through the duration of this research indicate that the temperature variation throughout the port is the principal contributor to the characteristics of the sound velocity profile. Ambient noise measurements have revealed high levels of background noise within the sub-5 kHz region, owing likely to consistent port traffic. The calculation of absorption indicates that high frequency systems, i.e. > 100 kHz, may encounter problems when transmitting over a considerable distance. These are important factors for consideration when implementing a successful underwater acoustic system.
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Date Issued
2007
PURL
http://purl.flvc.org/fau/fd/FA00012553
Subject Headings
Underwater acoustics--Measurement, Port Everglades (Fort Lauderdale, Fla), Harbors--Environmental aspects--Florida--Fort Lauderdale, Acoustic surface waves--Measurement
Format
Document (PDF)
Automated Launch and Recovery of an Autonomous Underwater Vehicle from an Unmanned Surface Vessel
Title
Automated Launch and Recovery of an Autonomous Underwater Vehicle from an Unmanned Surface Vessel.
Creator
Sarda, Edoardo I, Dhanak, Manhar R., Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
Research on collaboration among unmanned platforms is essential to improve the applications for autonomous missions, by expanding the working environment of the robotic systems, and reducing the risks and the costs associated with conducting manned operations. This research is devoted to enable the collaboration between an Unmanned Surface Vehicle (USV) and an Autonomous Underwater Vehicle (AUV), by allowing the first one to launch and recover the second one. The objective of this...
Show moreResearch on collaboration among unmanned platforms is essential to improve the applications for autonomous missions, by expanding the working environment of the robotic systems, and reducing the risks and the costs associated with conducting manned operations. This research is devoted to enable the collaboration between an Unmanned Surface Vehicle (USV) and an Autonomous Underwater Vehicle (AUV), by allowing the first one to launch and recover the second one. The objective of this dissertation is to identify possible methods to launch and recover a REMUS 100 AUV from a WAM-V 16 USV, thus developing this capability by designing and implementing a launch and recovery system (LARS). To meet this objective, a series of preliminary experiments was first performed to identify two distinct methods to launch and recover the AUV: mobile and semi-stationary. Both methods have been simulated using the Orcaflex software. Subsequently, the necessary control systems to create the mandatory USV autonomy for the purpose of launch and recovery were developed. Specifically, a series of low-level controllers were designed and implemented to enable two autonomous maneuvers on the USV: station-keeping and speed & heading control. In addition, a level of intelligence to autonomously identify the optimal operating conditions within the vehicles' working environment, was derived and integrated on the USV. Lastly, a LARS was designed and implemented on the vehicles to perform the operation following the proposed methodology. The LARS and all subsystems developed for this research were extensively tested through sea-trials. The methodology for launch and recovery, the design of the LARS and the experimental findings are reported in this document.
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Date Issued
2016
PURL
http://purl.flvc.org/fau/fd/FA00004631, http://purl.flvc.org/fau/fd/FA00004631
Subject Headings
Underwater acoustic telemetry., Fuzzy systems., Nonlinear control theory., Adaptive signal processing., Oceanographic submersibles--Automatic control., Submersibles--Control systems.
Format
Document (PDF)
A high-level fuzzy logic guidance system for an unmanned surface vehicle (USV) tasked to perform an autonomous launch and recovery (ALR) of an unmanned underwater vehicle (UUV)
Title
A high-level fuzzy logic guidance system for an unmanned surface vehicle (USV) tasked to perform an autonomous launch and recovery (ALR) of an unmanned underwater vehicle (UUV).
Creator
Pearson, David, An, Pak-Cheung, Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
There have been much technological advances and research in Unmanned Surface Vehicles (USV) as a support and delivery platform for Autonomous/Unmanned Underwater Vehicles (AUV/UUV). Advantages include extending underwater search and survey operations time and reach, improving underwater positioning and mission awareness, in addition to minimizing the costs and risks associated with similar manned vessel operations. The objective of this thesis is to present the design and development a high...
Show moreThere have been much technological advances and research in Unmanned Surface Vehicles (USV) as a support and delivery platform for Autonomous/Unmanned Underwater Vehicles (AUV/UUV). Advantages include extending underwater search and survey operations time and reach, improving underwater positioning and mission awareness, in addition to minimizing the costs and risks associated with similar manned vessel operations. The objective of this thesis is to present the design and development a high-level fuzzy logic guidance controller for a WAM-V 14 USV in order to autonomously launch and recover a REMUS 100 AUV. The approach to meeting this objective is to develop ability for the USV to intercept and rendezvous with an AUV that is in transit in order to maximize the probability of a final mobile docking maneuver. Specifically, a fuzzy logic Rendezvous Docking controller has been developed that generates Waypoint-Heading goals for the USV to minimize the cross-track errors between the USV and AUV. A subsequent fuzzy logic Waypoint-Heading controller has been developed to provide the desired heading and speed commands to the low-level controller given the Waypoint-Heading goals. High-level mission control has been extensively simulated using Matlab and partially characterized in real-time during testing. Detailed simulation, experimental results and findings will be reported in this paper.
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Date Issued
2014
PURL
http://purl.flvc.org/fau/fd/FA00004315, http://purl.flvc.org/fau/fd/FA00004315
Subject Headings
Adaptive signal processing, Fuzzy sets, Fuzzy systems, Nonlinear control theory, Oceanographic submersibles -- Automatic control, Submersibles -- Control systems, Underwater acoustic telemetry
Format
Document (PDF)
A Study of the Underwater Acoustic Propagation in a Turning Basin Modeled as a Three-Dimensional Duct Closed at One End Using the Method of Images
Title
A Study of the Underwater Acoustic Propagation in a Turning Basin Modeled as a Three-Dimensional Duct Closed at One End Using the Method of Images.
Creator
Staska, Matthew D., Beaujean, Pierre-Philippe, Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
A computer-efficient model of the underwater acoustic propagation m a shallow, three-dimensional duct closed at one end has been developed using the method of images. Presented in this research is the development of this three-dimensional method of images analysis for a rectangular duct. Using this analysis, a model of the impulse response of the acoustic channel is constructed. Also presented in this work is the actual impulse response collected during field experimentation in the south...
Show moreA computer-efficient model of the underwater acoustic propagation m a shallow, three-dimensional duct closed at one end has been developed using the method of images. Presented in this research is the development of this three-dimensional method of images analysis for a rectangular duct. Using this analysis, a model of the impulse response of the acoustic channel is constructed. Also presented in this work is the actual impulse response collected during field experimentation in the south turning basin of Port Everglades in Fort Lauderdale, Florida. The results demonstrate that the impulse response is modeled with a relative echo magnitude error of 1.62 dB at worst, and a relative echo location error varying between 0% and 4% when averaged across multiple measurements and sensor locations.
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Date Issued
2007
PURL
http://purl.flvc.org/fau/fd/FA00012557
Subject Headings
Underwater acoustics--Measurement, Wave motion, Theory of, Wave equation--Numerical solutions, Sound-waves--Transmission--Mathematical models
Format
Document (PDF)
Development of an intelligent fuzzy obstacle avoidance system using SONAR modeling and simulation
Title
Development of an intelligent fuzzy obstacle avoidance system using SONAR modeling and simulation.
Creator
Bouxsein, Philip A., Florida Atlantic University, An, Edgar
Abstract/Description
Response time to a threat or incident for coastline security is an area needing improvement. Currently, the U.S. Coast Guard is tasked with monitoring and responding to threats in coastal and port environments using boats or planes, and SCUBA divers. This can significantly hinder the response time to an incident. A solution to this problem is to use autonomous underwater vehicles (AUVs) to continuously monitor a port. The AUV must be able to navigate the environment without colliding into...
Show moreResponse time to a threat or incident for coastline security is an area needing improvement. Currently, the U.S. Coast Guard is tasked with monitoring and responding to threats in coastal and port environments using boats or planes, and SCUBA divers. This can significantly hinder the response time to an incident. A solution to this problem is to use autonomous underwater vehicles (AUVs) to continuously monitor a port. The AUV must be able to navigate the environment without colliding into objects for it to operate effectively. Therefore, an obstacle avoidance system (OAS) is essential to the activity of the AUV. This thesis describes a systematic approach to characterize the OAS performance in terms of environments, obstacles, SONAR configuration and signal processing methods via modeling and simulation. A fuzzy logic based OAS is created using the simulation. Subsequent testing of the OAS demonstrates its effectiveness in unknown environments.
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Date Issued
2006
PURL
http://purl.flvc.org/fcla/dt/13390
Subject Headings
Fuzzy logic, Submersibles--Automatic control, Neural networks (Computer science), Underwater acoustics--Computer simulation, Sonar--Computer simulation
Format
Document (PDF)
Passive acoustics as a monitoring tool for evaluating oyster reef restoration
Title
Passive acoustics as a monitoring tool for evaluating oyster reef restoration.
Creator
Zenil Becerra, Hilde P., Charles E. Schmidt College of Science, Center for Environmental Studies
Abstract/Description
Oyster reefs are biodiverse communities that provide many ecological and commercial benefits. However, oyster reefs have declined around the world from human activities. Oyster reef restoration programs have begun to limit some of the decline, but the need for determining the success of a program has been problematic. Passive acoustic techniques can use naturally occurring sounds produced by organisms to assess biodiversity. Passive acoustics was utilized to compare the sounds in natural and...
Show moreOyster reefs are biodiverse communities that provide many ecological and commercial benefits. However, oyster reefs have declined around the world from human activities. Oyster reef restoration programs have begun to limit some of the decline, but the need for determining the success of a program has been problematic. Passive acoustic techniques can use naturally occurring sounds produced by organisms to assess biodiversity. Passive acoustics was utilized to compare the sounds in natural and restored oyster reefs, with special attention on snapping shrimp (Alpheus spp.) snap sounds, in the St. Lucie Estuary, Florida over a one year period. Season, estuary region, habitat and day period had an effect on sound production. Passive acoustic monitoring of snapping shrimp sound production may be a useful non-destructive technique for monitoring the progress of oyster reef restoration projects once further correlations are established between environmental effects and sound production.
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Date Issued
2012
PURL
http://purl.flvc.org/FAU/3352882
Subject Headings
American oyster, Ecosystem management, Restoration ecology, Aquatic ecology, Underwater acoustics
Format
Document (PDF)

Pages