Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 63 for “"radar cross section"”.
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Reduction of a Radar Cross Section Using Active Antenna Elements
… traditional approaches to reducing an object's radar cross section are passive in nature, such as changing the shape of an object or coating the object with a non-reflecting material. Examples of passive applications of traditional approaches to RCS reduction are the Lockheed-Martin F-117 …
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Manipulation of antenna-mode radar cross-section in patch antennas
The Radar Cross-Section (RCS) of an antenna has two main components: structural RCS and antenna-mode RCS. Structural RCS is due to the physical geometry of the antenna. The antenna-mode RCS component is due to load impedance mismatches and can be manipulated by changing the load impedance connected …
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Finite difference techniques for body of revolution radar cross section
Although a number of radar cross section prediction techniques have been developed which exploit body of revolution symmetry, the use of finite-difference techniques with these geometries has not been throughly explored. This thesis investigates several finite-difference approaches which vary both …
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Radar cross-section data encoding based on parametric spectral estimation techniques
… This research applies parametric modeling to radar cross section data in an attempt to encode it as well as preserve its spectrum. Traditionally, radar data has been processed through Fourier spectral estimation techniques. These methods not only require large amounts of data, for good …
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Graphical user interface for a physical optics radar cross section prediction code
… optics approximation method for predicting the radar cross section (RCS) of complex objects utilizes the scientific computational features of MATLAB and its Graphical User Interface (Gui) functions to provide an error-free encoding of input parameters and efficient calculation. The POFACETS GUI …
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Spectral-Iterative Analysis of Electromagnetic Radiation and Scattering Problems (radar-Cross-Section, Integral Equation)
Integral equations in electromagnetics typically are convolutional in nature. When the geometry of the problem permits, the unknown function can be expanded in a set of identical, evenly spaced basis functions. If the integral equation is tested in the same way, the continuous convolutions reduce …
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A Higher-Order Finite Element Method for Computing the Radar Cross Section of Bodies of Revolution
… element method (FEM) is used to compute the radar cross section (RCS) of bodies of revolution (BORs). The FEM described here uses scalar basis functions for the &phis; component of the field and vector basis functions for the transverse component of the field. Higher-order basis functions are …
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Extension of a high-order Petrov-Galerkin implementation applied to non-radiating and radar cross section geometries
… A simple sphere case is used to exercise the radar cross section (RCS) routines and to examine the benefits of curving elements for high-order simulations.
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The Impact of Plasma Formation on the Radar Cross-Section of Objects in Hypersonic Sub-Orbital Flight
L'abstract è presente nell'allegato / the abstract is in the attachment
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Scattering From a Circular Waveguide Coated With Lossy Material (Radar Cross-Section, Jet Intake, Gtd, Magnetic, Equivalent Current)
… is given to the reduction scheme of the radar cross section (RCS) from such a structure.
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Design, Simulation and Analysis of A Low Radar Cross Section Uhf Circular Microstrip Patch Antenna and Radome For United States Naval Fleet Broadcast Applications
… legacy ship designs to cut down on the overall radar cross section of the ship. While modifying a ship's overall shape can reduce the radar cross section, there's one factor that still contributes to RCS which isn't affected by changing the shape of the ship and that's the topside radiators, …
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A simulation of the single scan accuracy of a two-dimensional pulsed surveillance radar
… positional accuracy of a pulsed surveillance radar. The theoretical aspects to the positional accuracy are considered and a generalized analytical approach is presented. Practical position estimators are often complex, and theoretical predictions of their performance generally yield unfriendly …
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Determination of Bragg Scatter in an Aircraft Generated Wake Vortex System for Radar Detection
… have demonstrated that there is sufficient radar cross section for remote detection at frequencies ranging from VHF to C band (100 MHz to 5 GHz). The mechanism that yields this radar cross section is Bragg scattering from the index of refraction variations due to the atmospheric water vapor …
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Synthetic aperture radar image simulator for interferometry
An interferometric synthetic aperture radar (SAR) simulator was created for the purposes of experimenting with and demonstration of the interferometric process, mission planning and radar image interpretation. The simulation method employs image statistics and terrain geometry to form a synthetic …
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Electromagnetic scattering from a structured slab comprised of periodically placed resistive cards
… structured slab has also been used to reduce the radar cross section of various aircraft. It is important, therefore, to characterize how an electromagnetic wave scatters from this slab. The structured slabs discussed in this thesis are constructed by repeating lossy strips periodically in one …
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Numerical study on the validity of the quasi-specular and two-scale models for rough surface parameter estimation: one dimensional surfaces
… rough surface parameters from the average radar cross section of randomly rough surfaces, with the goal of understanding what scattering mechanisms limit their applicability. The ranges of validity of these models are ascertained by comparing the average backscattered normalized radar cross …
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Cavity-backed T-fed slot antenna
… and conformal antennas which have a low radar cross section out of their operating frequency bands. Like thin microstrip patch antennas, cavity-backed slot antennas typically have a narrow impedance bandwidth of 1 to 6 percent of center frequency, which limits their usage. A new method of …
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Multiple region finite-difference time-domain modeling of duct cavities
Although many radar cross section prediction techniques exist, none have proven to be completely satisfactory when applied to large cavities. Exact numerical techniques can accurately predict RCS, but are too computationally expensive to be used for many cavity geometries. High frequency techniques …
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Solar flare effects observed over Jicamarca during MST-ISR experiments
… The observations were made while the Jicamarca radar was conducting combined observations in mesosphere-stratosphere-troposphere (MST) and incoherent scatter radar (ISR) modes. Combined MST-ISR campaigns have been conducted at JRO from December 2004 until January 2009 with the purpose of …
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Computer-aided design-based high-frequency electromagnetic wave scattering from complex bodies
… packages. The scattering analyses are applied to radar cross section (RCS) problems, cavity radiation problems, and antenna pattern predictions of complex electrically large structures, thereby showing that it is feasible to accurately approximate the electromagnetic wave scattering from general …
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