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 11 of 11 for “"Orbit Propagation"”.
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Parallel orbit propagation and the analysis of satellite constellations
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1995.
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Reduced-Order Atmospheric Density Modeling for LEO Satellite Orbital Reentry Prediction
… uncertainty quantification for fast and accurate orbit propagation are vital to drag force estimation for satellite reentry prediction and conjunction assessment in today's increasingly cluttered Low Earth Orbit (LEO) environment. Current density models can be computationally expensive, and often …
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The Feasibility and Application of Observing Small LEO Satellites with Amateur Telescopes
… brightness prediction model, angles-only orbit determination including extended Kalman filtering, and temporal error growth in TLE-based orbit propagation. Further investigations include a preliminary optimization using MATLAB's fmincon function (informed by the previous analyses) to …
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Application of optimization techniques to the design and maintenance of satellite constellations
… algorithms were used in conjunction with precise orbit propagation schemes to develop robust orbit optimization tools. Specifically, local and global optimization methods were used to design a 113:14 repeat ground track variant of the Ellipso TM inclined elliptical sub-constellation and a gear …
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Open Source Toolkit for Reentry Object Modeling
… and ESA requirements. This thesis outlines a 3-D orbit and mass determination system for use on low earth orbit as applicable to general objects, of various material and size. The solution uses analytical models to calculate heat flux and aerodynamic drag, with some basic numerical models for …
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Modeling and Analysis of a Thermospheric Density Measurement System Based on Torque Estimation
… the density of the thermosphere at low Earth orbit (LEO) altitudes in real time. As satellites orbit in the thermosphere, the sparse yet present air perturbs their orbits via the drag force. The drag force is poorly characterized and has a significant effect at LEO altitudes relative to other …
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Evolution of artificial space debris clouds
Over 120 cases of on-orbit breakups have now been recorded. Many more undetected events are believed to have occurred. Each time an object breaks up, whether by explosion or collision, a cloud of debris is formed. The overall objective of the PhD is to examine the interaction between the debris …
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A Variable-Step Double-Integration Multi-Step Integrator
… require numerical integration methods to track orbiting objects accurately. Because of the large number of objects being processed, methods that can integrate the equations of motion as fast as possible while maintaining accuracy requirements are desired. The force model used for earth-orbiting …
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Mission Planning Tool for space debris studies with the MeerKAT radar
… and errors as well as to estimate the orbit of the observed object. This report documents how these objectives were met by the MPT software developed in Python. Given a LEO space object of interest’s Two Line Element set, the MPT performs orbit propagation with an SGP4 method to …
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Spacecraft trajectory optimization using many embedded Lambert problems
… shown to share similar behavior for Keplerian orbit propagation. The PST functions are also shown to extend the EBVP technique to a large design space, where a runtime-feasible transfer with 512 revs and 12287 segments is presented that significantly changes semimajor axis, eccentricity, and …
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Investigating the use of ray tracing for signal-level radar simulation in space monitoring applications: a comparison of radio propagation models
… on space debris monitoring in the Low Earth Orbit. Space surveillance represents a major topic of concern to astronomers as the threat of space debris and orbital overpopulation looms – particularly due to the lack of effective mitigation techniques and the limitations of modern …