Thesis (Ph. D.)--University of Rhode Island, 2005. / Typescript. Includes bibliographical references (leaves 221-223).

This thesis is focused on possibility of constructing distributed underwater sonar which has an ability to increase or decrease number of sensor elements without any modification on its hardware. Each sonar module works individually. Its synchronization and communication between modules and the image processing unit are archived by using CAN protocol. This new design concept gives several advantages over conventional design.Only one prototype was made, but several modules must be combined in the actual application. The discussion about a complete system can be found in the future work section.The project composes of two main parts: design and building a prototype. The testing procedure and result of both parts are described and summarized with a conclusion.

No description available.

No description available.

Abstract Recovery of underwater drowned human body is one of the major missions of the firefighters. However, due to short of man power, lack of training and professional equipments, this kind of body recovery mission was basically conducted on the shore and at the water surface. Only a limited amount (if any) of diving activities were conducted to search for the drowned body. For a much more efficient way to conduct this kind of body recovery activity, it is necessary to incorporate the state of the art of the underwater acoustics technique, such as scanning sonar, into the operation procedures. Underwater stationary targets are objects sitting on the seafloor that can¡¦t move autonomously. Apparatus feasible for the detection of these underwater stationary targets includes: optics, acoustics and geophysical instruments. Among them, acoustical apparatus is the most feasible one. The purpose of this research was to investigate the application of scanning sonar for underwater human body detection and recovery. Based on theoretical considerations, the use of scanning sonar can improve both total time consumed and target detection rate of body recovery rescue activities. Three real cases which incorporated this equipment into the rescue work illustrated that the movement of a diver, several suspected targets and the morphological features around the targets can be recognized by the scanning sonar. In addition, the dimensions, shapes, amount and geographic locations of the targets can be identified for further considerations. During the mission at the Jih-Yueh-Tan Reservoir, it was proved indirectly that the scanning sonar can detect the drowned human body successively. Based on this investigation, it is recomended that the detection and identification ability of the scanning sonar can be dramatically improved if optical apparatus such as ROV (remotely operated vehicle) or TOV (towed operated vehicle) was incorporated into the operation procedures.

Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, September 1990. / Thesis Advisor(s): Morgan, Michael A. Second Reader: Adler, Richard W. "September 1990." Description based on title screen viewed on December 17, 2009. DTIC Descriptor(s): Electromagnetism, target signatures, models, target recognition, waveforms, theses, electromagnetic scattering, finite difference theory, resonant frequency, echoes, resonance, recursive functions, acoustic scattering, transients, verification. DTIC Identifier(s): Radar scattering, sonar scattering, army models, program listings. Author(s) subject terms: Natural resonances; electromagnetic scattering; acoustic scattering; radar target identification; prony's method; ARMA model. Includes bibliographical references (p. 81-82). Also available in print.

Thesis (M.S.)--Ohio University, June, 1988. / Title from PDF t.p.

Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, December 1990. / Thesis Advisor(s): Lee, Chin-Hwa. Second Reader: Therrien, Charles W. "December 1990." Description based on title screen as viewed on April 02, 2010. DTIC Descriptor(s): Simulation, optimization, detection, sonar, edges, theses, sensitivity, noise, annealing, detectors DTIC Identifier(s): Sonar tracking, edge detectors, signal to noise ratio, combinatorial optimization, simulation. Author(s) subject terms: Simulated annealing, sonar track detection, combinatorial optimization Includes bibliographical references (p. 59). Also available in print.

No description available.

Localization is a classic and complex problem in the field of mobile robotics. It becomes particularly challenging in an aqueous environment because currents within the water can move the robot. A novel localization module and corresponding localization algorithm for experimental autonomous underwater vehicles is presented. Unlike other available positioning systems which require fixed hardware beacons, this custom built module relies only on information available from sensors on-board the vehicle and knowledge of its bounded domain. This allows the user to save valuable time which would otherwise be devoted to the setup and calibration of a beacon or sensor network. The module uses three orthogonal ultrasonic transducers to measure distances to the tank boundaries. Using the measured tri-axial orientation of the vehicle, the algorithm analytically determines the robot's position within the domain in absolute coordinates. Certain vehicle states do not allow the position to be completely resolved by the algorithm alone. In this case, state estimation is used to estimate the robot position until its state is no longer indeterminate. The modular design of this system makes it ideal for application on underwater vehicles which operate in a bounded environment for research purposes. An experimental version of the module was constructed and tested in the WPI swimming pool and showed successful localization under normal conditions.