Made available in DSpace on 2016-06-02T19:14:59Z (GMT). No. of bitstreams: 1 5410.pdf: 2286811 bytes, checksum: 5992c36bb680140d19c9b5e348cfea97 (MD5) Previous issue date: 2013-03-20 / Financiadora de Estudos e Projetos / This work aims to analyze the technological modernization of the Brazilian Navy in the period between 1942 and 1970. Despite starting the Second World War without conditions of defending the country, the Brazilian Navy has modernized with American support, equipping it with modern anti-submarine equipment within the concept of hemispheric defense. At the end of the conflict and start of the Cold War, U.S. politics for the Latin America changed, and the Brazilian Navy stopped receiving modern military equipment from that country. Nevertheless, most Brazilian officers continued supporting the principles of the hemispheric defense, which mean subordination, strategic and intellectual, to the U.S. Navy. For much of the following decades, despite the changes in the foreign policy and investments in scientific and technological research in Brazil, the Brazilian Navy continued subordinated to the concept of hemispheric defense, with an obsolete fleet and unable to get modern ships. In late 1960s, the Brazilian Navy begins to face difficulties in acquiring modern weapons because of changes in the U.S. politics, culminating in the acquisition of British frigates, which despite having great emphasis on anti-submarine warfare, mark the recovery of shipbuilding in Brazil, the beginning of the withdrawal of the material and intellectual dependence on the U.S. and a major technological leap in the Brazilian Navy. / Este trabalho tem como objetivo analisar a modernização tecnológica da Marinha Brasileira no período entre 1942 e 1970. Apesar de iniciar a Segunda Guerra Mundial sem condições de defender o país, a Marinha se modernizou, com recursos norteamericanos, equipando-se com moderno equipamento antissubmarino, dentro da concepção de defesa hemisférica. Ao final do conflito e início da Guerra Fria, a política dos EUA para a América Latina mudou, e a Marinha parou de receber equipamentos militares modernos daquele país. Apesar disso, a maioria dos oficiais continuou apoiando os princípios de defesa hemisférica, o que significava a subordinação, estratégica e intelectual, à marinha norte-americana. Durante grande parte das décadas seguintes, a despeito das mudanças na política externa e investimentos na pesquisa científica e tecnológica no Brasil, a Marinha continuou subordinada à concepção de defesa hemisférica, com uma frota obsoleta e sem conseguir navios modernos. Já no final dos anos de 1960, a Marinha começa a enfrentar dificuldades na aquisição de armamentos por mudanças na política norte-americana, que culminam na aquisição de fragatas britânicas, que apesar de ainda terem grande ênfase na guerra antissubmarino, marcam a retomada da construção naval no país, o início do afastamento da dependência material e intelectual dos EUA e num importante salto tecnológico na Marinha.

The use of magnetometers combined with unmanned aerial vehicles (UAVs) is an emerging market for commercial and military applications. This study presents the methodology used to magnetically characterize a novel fixed-wing vertical take-off and landing (VTOL) UAV. The most challenging aspect of integrating magnetometers on manned or unmanned aircraft is minimizing the amount of magnetic noise generated by the aircraft’s onboard components. As magnetometer technology has improved in recent years magnetometer payloads have decreased in size. As a result, there has been an increase in opportunities to employ small to medium UAV with magnetometer applications. However, in comparison to manned aviation, small UAVs have smaller distance scales between sources of interference and sensors. Therefore, more robust magnetic characterization techniques are required specifically for UAVs. This characterization determined the most suitable position for the magnetometer payload by evaluating the aircraft’s static-field magnetic signature. For each aircraft component, the permanent and induced magnetic dipole moment characteristics were determined experimentally. These dipole characteristics were used to build three dimensional magnetic models of the aircraft. By assembling the dipoles in 3D space, analytical and numerical static-field solutions were obtained using MATLAB computational and COMSOL finite element analysis frameworks. Finally, Tolles and Lawson aeromagnetic compensation coefficients were computed and compared to evaluate the maneuver noise for various payload locations. The magnetic models were used to study the sensitivity of the aircraft configuration and to simultaneously predict the effects at potential sensor locations. The study concluded by predicting that a wingtip location was the area of lowest magnetic interference. / Graduate

Approved for public release, distribution is unlimited / In this thesis, the ocean was modeled as a waveguide with an ideal pressure - release surface, and an ideal rigid bottom. The ocean waveguide was then treated as a linear, time - invariant, space - variant (TISV) filter or communication channel. The filter is time - invariant because no motion was modeled and because the properties of the ocean were assumed to be constant. The filter is space - variant because of the presence of the two boundaries, that is, the ocean surface and ocean bottom. This thesis investigates the ocean as a linear TISV filter by evaluating 1) the complex frequency response, 2) the impulse response, and 3) the transfer function of the ocean with respect to depth. It is shown that the TISV impulse response of the ocean contains information that can be used to help localize a target in range and whether the target is above or below the receiver. Computer simulation results were obtained by evaluating the three filter functions for several different test cases. / Ensign, United States Navy