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 53 for “"satellite constellations"”.
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Automated station-keeping for satellite constellations
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1997.
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Medium Access Control Protocol for Satellite Constellations
Satellite internet constellations have emerged as a promising solution for providing global internet connectivity, especially in regions underserved by terrestrial infrastructure. However, as user demand increases, especially in densely populated urban areas, existing Medium Access Control (MAC) …
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Reconfigurable Satellite Constellations for Mobile Target Tracking
Current storm monitoring satellites offer unsatisfactory coverage of ongoing storms, either obtaining low spatial resolution, persistent coverage or high spatial resolution coverage with low temporal sampling. A reconfigurable constellation of satellites (ReCon) offers a way to augment these data …
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LOW-THRUST CONTROLLER FOR SLOT-BASED SATELLITE CONSTELLATIONS
Due to the increase in popularity of satellite constellations, some altitudes in LEO have experienced a large increase in number of satellites. This is a trend expected to continue in the future, which could potentially lead to an increased risk of collision between satellites. Collision avoidance …
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Optimizing resource allocation in large communications satellite constellations
Satellite communications are becoming a key technology for maintaining connectivity in a world driven by information. In the recent years, established players (such as SES and Telesat), as well as new competitors (such as SpaceX and Amazon) have proposed constellations able to serve hundreds of …
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Onboard distributed replanning for crosslinked small satellite constellations
… and scheduling approach for crosslinked small satellites Earth observation missions. The example cases used involve 65 small satellites in ISS and Sun Synchronous Orbits, as well as NASA's Near Earth Network groundstations, and three target cases. Target cases include urgent observations. This …
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Debris collision avoidance maneuver optimization (CAMO) for satellite constellations
… to the sustainability of current and future satellite constellations. Traditional collision avoidance strategies, which typically rely on single-impulse maneuvers executed in response to ground-based warnings, often suffer from high propellant costs and operational inefficiencies due to late …
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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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Planning and scheduling for earth-observing small satellite constellations
The growth of Earth-observing small satellite constellations requires effective, automated operations management. State-of-the-art techniques must be improved to manage scheduling of observation data collection, data routing through a crosslinked constellation network, and maintenance of limited …
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Optimization and valuation of recongurable satellite constellations under uncertainty/
… strategy that utilizes on-demand, maneuverable satellites to provide focused regional coverage with short revisit times at greatly decreased cost when compared to traditional static satellite constellations. The thesis develops and demonstrates a general framework to guide the design and …
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Reconfigurable satellite constellations for geo-spatially adaptive Earth observation missions
… as unmanned aerial systems (UAS) or artificial satellites. Space-based architectures can provide non-dominated design solutions on the utility-cost curve compared to alternate architectures through the use of two approaches: (1) reducing satellite manufacturing and launch costs and (2) …
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Expanded tradespace analysis and operational considerations for reconfigurable satellite constellations
Earth observation (EO) satellites provide helpful imagery to a variety of applications ranging from weather monitoring to agricultural support. Disaster response imaging is an essential but difficult application for EO to support. Reconfigurable satellite constellations (ReCon) provide a flexible …
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A systemic approach toward scalable, reliable and safe satellite constellations
Constellations of hundreds to thousands of satellites are becoming a reality. Nevertheless, the unprecedented scale of these systems is creating new sorts of challenges and risks for the designers and operators, mainly due to the high level of automation required. This study demonstrates how …
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Topologies for satellite constellations in a cross-linked space backbone network
… space data network can be formed from satellites serving as both backbone and user-access nodes connected via high-speed cross-links. Such a space backbone network should support spacecraft-to-ground and spacecraft-to-spacecraft links for users of various altitudes (LEO, MEO, GEO and …
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A complete resource allocation framework for flexible high throughput satellite constellations
… been a witness for the rise of the new era of satellite communications. The interest for providing broadband access from space has reached levels that remind of those in the late 90s with Iridium and Globalstar among others. The novel mega-constellation designs will rely on thousands of highly …
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Application of optimization techniques to the design and maintenance of satellite constellations
… in both the design and maintenance of satellite constellations. Powell's method and parallel genetic 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 …
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Enhancing the economics of satellite constellations via staged deployment and orbital reconfiguration
The "traditional" way of designing constellations of communications satellites is to optimize the design for a specific global capacity. This approach is based on a forecast of the expected number of users and their activity level, both of which are highly uncertain. It can lead to economic failure …
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Enhancing Satellite Constellations with Scalable Network Simulation and Rapid Passive Safety Assessment
… simulation with rapid collision assessment for satellite constellations. A key contribution is the introduction of a novel, rapid passive safety-checking method based on closed-form analysis of relative orbital elements and exact geometric envelopes. By mapping satellite dynamics to the …
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Capacity provisioning, failure recovery and throughput analysis for low earth orbit satellite constellations
… the capacity needed to build a restorable satellite network and design routing schemes to achieve high throughput. Specifically, the first part of this thesis considers the link capacity requirement for a LEO satellite constellation. We model the constellation as an N x N mesh-torus …
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Quantifying technology infusion and policy impact on low earth orbit communication satellite constellations
… results. The low earth orbit (LEO) communication satellite constellation system serves as the platform for carrying out the system trade space analysis. The system is reproduced in computer environment in the form of a multiple-input-output MATLAB model. The model contains multiple modules that …
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