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 12 of 12 for “"Sparse aperture"”.
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Sparse Aperture Speckle Interferometry Telescope Active Optics Control System
<p>A conventional large aperture telescope required for binary star research is typically cost prohibitive. A prototype active optics system was created and fitted to a telescope frame using relatively low cost components. The active optics system was capable of tipping, tilting, and elevating the …
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Design, implementation and control of a sparse aperture imaging satellite
… will inevitably lead to larger and larger apertures. Unfortunately, the diameter size of primary mirrors for space telescopes is limited by the volume and mass constraints of current launch vehicles as well as the scaling laws of manufacturing costs. Efforts are ongoing to break this trend …
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Investigation of spacecraft cluster autonomy through an acoustic imaging interferometric testbed
… have been proposed for applications in sparse aperture radar or astronomical observations. Modeled after these systems, an integrated hardware and software interferometry testbed is developed. Utilizing acoustic sources and sensors as a simplified analog to radio or optical systems, the …
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Performance analysis of a space-based GMTI radar system using separated spacecraft interferometry
… assess the radar performance capabilities of a sparse aperture space-based GMTI radar system is presented. Airborne radars have provided reliable detection of moving targets for many years. Recent technological advancements have allowed the deployment of radar systems in space to improve global …
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Spacecraft formation flight exploiting potential fields
… the Earth's gravitational field. Based upon the sparse aperture radar requirements, the terminal conditions required to keep the Air Force TechSat 21 Earth orbiting clusters in closed formations were derived. Using the Linear Quadratic formulation, the optimal reconfigurations required to …
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Electromagnetic formation flight of satellite arrays
Proposed methods of actuating spacecraft in sparse aperture arrays use propellant as a reaction mass. For formation flying systems, propellant becomes a critical consumable which can be quickly exhausted while maintaining relative orientation. Furthermore, the total required propellant mass is …
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Modeling Satellite Formations In The Presence Of Perturbations
… areas as high- resolution remote sensing, and sparse aperture radar, has stimulated interest in modeling the satellite environment for feasibility and simulation studies to help explore and define the technical challenges that must be solved in order to achieve successful autonomous satellite …
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Development of resource-constrained sensors and actuators for in-space satellite docking and servicing
… spaceflight systems, with applications to sparse aperture telescopes, solar power stations, fuel depots and space habitats. The purpose of this thesis is to address the highest risk elements associated with the docking and servicing of satellites: the sensors, actuators, and associated …
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Optical communication through the turbulent atmosphere with transmitter and receiver diversity, wavefront control, and coherent detection
… system design and communication techniques for sparse aperture systems for the most general realistic case, one with inhomogeneous turbulence and imperfect (delayed, noisy, and distorted) knowledge of the atmospheric state.