Thesis (M.E.)--University of Canterbury, 2006. / Typescript (photocopy). "December 2006." Includes bibliographical references (p. 99-103). Also available via the World Wide Web.

Project report (M.S.)--Virginia Polytechnic Institute and State University, 1990. / Includes bibliographical references (leaves 164-166). Also available via the Internet.

Thesis (M.S.)--University of Delaware, 2007. / Principal faculty advisor: John A. Madsen, Dept. of Geological Sciences. Includes bibliographical references.

Thesis (M.S. in Meteorology and Physical Oceanography)--Naval Postgraduate School, September 2009. / Thesis Advisor(s): Chu, Peter. "September 2009." Description based on title screen as viewed on November 5, 2009. Author(s) subject terms: Mine Warfare, periodicity, route survey, oceanographic, key parameters, resurvey integration model, survey model. Includes bibliographical references (p. 55-56). Also available in print.

Thesis (M.S. in Engineering Acoustics)--Naval Postgraduate School, December 2002. / Thesis advisor(s): Kevin B. Smith, Peter H. Dahl. Includes bibliographical references (p. 53). Also available online.

Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, June 2005. / Thesis Advisor(s): Anthony J. Healey. Includes bibliographical references (p. 41-42). Also available online.

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Sonar is an important sensory modality for engineers as well as in nature. In engineering, sonar is the dominating modality for underwater sensing. In biology, it is likely to have been a central factor behind the unprecedented evolutionary success of bats, a highly diverse group that accounts for over 20% of all mammal species. However, it remains unclear to what extent engineered and biosonar follow similar design and operational principles. In the current work, the key sonar design characteristic of beamwidth is examined in technical and biosonar. To this end, beamwidth data has been obtained for 23 engineered sonar systems and from numerical beampattern predictions for 151 emission and reception elements (noseleaves and pinnae) from bat biosonar. Beamwidth data from these sources is compared to the beamwidth of a planar ellipsoidal transducer as a reference. The results show that engineered and biological both obey the basic physical limit on beamwidth as a function of the ratio of aperture size and wavelength. However, beyond that, the beamwidth data revealed very different behaviors between the engineered and the biological sonar systems. Whereas the beamwidths of the technical sonar systems were very close to the planar transducer limit, the biological samples showed a very wide scatter away from this limit. This scatter was as large – if not wider – than what was seen in a small reference data set obtained with random aluminum cones. A possible interpretation of these differences in the variability could be that whereas sonar engineers try to minimize beamwidth subject to constraints on device size, the evolutionary optimization of bat biosonar beampatterns has been directed at other factors that have left beamwidth as a byproduct. Alternatively, the biosonar systems may require beamwidth values that are larger than the physical limit and differ between species and their sensory ecological niches. / Master of Science / Sonar is an important method of sensing for engineers in undersea environments, but it is also used by several species of animals for for everyday use. The most prominent species that uses sonar, or echolocation, are bats, one of the most diverse groups of mammals. The study of bat biosonar systems serves as a counterpoint to many of the concepts in technical sonar. In technical sonar, arrays are made to be larger in size, with more elements, and operate at higher frequencies in order to decrease their beamwidth which increases their resolution. Unlike technical sonars bats must rely on smaller sized systems that they can carry around and they operate in air which has worse qualities for propagating sound waves. Even with these disadvantages, bats are able to operate in complex environments, such as dense vegetation, with ease. This work compared 151 emission and reception elements of bat biosonar systems with 23 engineered sonars to find that the biosonar had very different behavior from the engineered sonars. The engineered sonars, as well as a set of experimental baffles, closely followed the curve for the beamwidth limit of planar transducers but the biosonar samples had a large scatter from the curve. These results could be interpreted to show that while the engineered sonars attempt to minimize the beamwidth in order to maximize the resolution, the biosonar did not place much importance on having low beamwidths and high resolutions during its evolution. Alternatively, the results could indicate that it is preferable for biosonar to have larger beamwidths, a contrast to standard sonar design.

In this Thesis work the development of a Software Simulation that allows closest offer at training to the reality for sonar operator’s personal in formation and described System sets out; with the objective to present the operability on board to Sonar device of the submarine units, as well as interaction with existing simulation modules inside the simulator Attack of Submarine Force of the Navy military of Peru, Located at the Submarine School. The Thesis is divided in four parts: the Introduction to the proposed subject and its problematic; Theoretical Frame that corresponds to variables that include the reach of this work; the State of the Art where a case in individual of a Sonar Simulator Software constructed under another programming language is exposed, which does not have similarity with electronic equipment sonar on board of the submarine units; finally the exposition of a development proposal, improvement and execution of a sonar simulator software that fulfills the functionality of the original electronic equipment on board. The hypothesis is in demonstrating that it’s possible to develop a sonar simulator software that allows to carry out functionalities of the original electronic equipment. Proven this throughout the Thesis, the objective is obtained: to demonstrate that it’s possible to construct a sonar simulator software that shows the contacts, generate the noise corresponding, sent the data necessary to other simulation modules, and simulating the Test containing in the original equipment. / En este trabajo de Tesis se propone el desarrollo de un Software de Simulación que permita brindar un entrenamiento más cercano a la realidad al personal de sonaristas en formación y calificado; con el objetivo de dar a conocer la operabilidad del sonar integrado a bordo de las unidades submarinas, así como la interacción con los módulos de simulación existentes en simulador de ataque de la Fuerza de Submarinos de la Marina de Guerra del Perú, ubicado en la Escuela de Submarinos. La Tesis se divide en cuatro partes: la Introducción al tema propuesto y su problemática; el Marco Teórico que corresponde a las variables que engloban el alcance de este trabajo; el Estado del Arte donde se expone un caso en particular de un software de simulación de sonar desarrollado bajo otro lenguaje de programación, el cual no tiene similitud con el sonar existente a bordo de las unidades submarinas; finalmente el planteamiento de una propuesta de desarrollo, mejoramiento y ejecución de un sistema simulador de sonar que cumpla con las funcionalidades del equipo de a bordo y se integre al sistema de simulación existente. La hipótesis está en demostrar que es posible desarrollar un software de simulación del sonar que permita realizar las funcionalidades que contiene el equipo original. Probado esto a lo largo de la Tesis, se logra el objetivo: demostrar que es posible construir un software simulador de sonar que muestra los contactos, genere el ruido sintético de las hélices, envié los datos necesarios a los otros módulos de simulación, y simule las pruebas Test que contiene el equipo original.