Download or read book A Collaborative Optimization Approach to Improve the Design and Deployment of Satellite Constellations written by Irene Arianti Budianto and published by . This book was released on 2000 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Enhancing the Economics of Satellite Constellations Via Staged Deployment and Orbital Reconfiguration written by Mathieu Chaize and published by . This book was released on 2003 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific Satellite and Moon Based Earth Observation for Global Change written by Huadong Guo and published by Springer. This book was released on 2019-06-27 with total page 641 pages. Available in PDF, EPUB and Kindle. Book excerpt: Global change involves complex and far-reaching variations in the Earth’s systems, and satellite observations have been widely used in global change studies. Over the past five decades, Earth observation has developed into a comprehensive system that can conduct dynamic monitoring of the land, the oceans and the atmosphere at the local, regional and even global scale. At the same time, although a large number of Earth observation satellites have been launched, very few of them are used in global change studies. The lack of scientific satellite programs greatly hinders research on global change. This book proposes using a series of global change scientific satellites to establish a scientific observation grid for global environmental change monitoring from space, and offers the first comprehensive review of lunar-based Earth observation. These scientific satellites could provide not only basic datasets but also scientific support in facilitating advances in international global change research.

Download or read book Mission Design Implementation of Satellite Constellations written by Jozef C. van der Ha and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 435 pages. Available in PDF, EPUB and Kindle. Book excerpt: The papers contained in this Volume of Proceedings have been collected from an international Workshop entitled 'Mission Design and Implementation of Satellite Constellations' which was held in Toulouse, France, in November 1997. This Workshop represented the first international gathering of the specialists in this currently very active field of research activity. The initiative to organise a Workshop around this theme was conceived during the Congress of the International Astronautical Federation (IAF) in Beijing, China, in October 1996. On that occasion, the IAF explored concepts and possibilities for the conduct of small specialist Workshops and Symposia of current interest. Topical, interesting, and focused themes in the general field of space technology (both theories and applications) will be selected for these Symposia. They aim at offering a dedicated forum at international level for specialists and experts to exchange their views and experiences on recent and future developments within the selected theme. These specialist Workshops and Symposia supplement the comprehensive annual IAF Congresses which cover all aspects of space technology and draw a correspondingly diverse audience.

Download or read book Astrodynamics written by Jean De La Fontaine and published by . This book was released on 2004 with total page 1012 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Optimizing Coverage and Revisit Time in Sparse Military Satellite Constellations A Comparison of Traditional Approaches and Genetic Algorithms written by and published by . This book was released on 2004 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sparse military satellite constellations were designed using two methods: a traditional approach and a genetic algorithm. One of the traditional constellation designs was the Discoverer II space based radar. Discoverer II was an 8 plane, 24 satellite, Low Earth Orbit (LEO), Walker constellation designed to provide high-range resolution ground moving target indication (HRR-GMTI), synthetic aperture radar (SAR) imaging and high resolution digital terrain mapping. The traditional method designed 9-ball, 12-ball, 18-ball, and 24-ball Walker constellations. The genetic algorithm created constellations by deriving a phenotype from a triploid genotype encoding of orbital elements. The performance of both design methods were compared using a computer simulation. The fitness of each constellation was calculated using maximum gap time, maximum revisit time, and percent coverage. The goal was to determine if one design method would consistently outperform the other. The genetic algorithm offered a fitness improvement over traditional constellation design methods in all cases except the 24-ball constellation where it demonstrated comparable results. The genetic algorithm improvement over the traditional constellations increased as the number of satellites per constellation decreased. A derived equation related revisit time to the number of ship tracks maintained.

Download or read book Analytical Approach to the Design of Optimal Satellite Constellations for Space based Space Situational Awareness Applications written by Ashley Darius Biria and published by . This book was released on 2011 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, the accumulation of space debris has become an increasingly pressing issue, and adequately monitoring it is a formidable task for designated ground-based sensors. Supplementing the capabilities of these ground-based networks with orbiting sensing platforms would dramatically enhance the ability of such systems to detect, track, identify, and characterize resident space objects -- the primary goals of modern space situational awareness (SSA). Space-based space situational awareness (SBSSA), then, is concerned with achieving the stated SSA goals through coordinated orbiting sensing platforms. To facilitate the design of satellite constellations that promote SSA goals, an optimization approach is selected, which inherently requires a pre-defined mathematical representation of a cost index or measure of merit. Such representations are often analytically available, but when considering optimal constellation design for SBSSA applications, a closed-form expression for the cost index is only available under certain assumptions. The present study focuses on a subset of cases that admit exact representations. In this case, geometrical arguments are employed to establish an analytical formulation for the coverage area provided as well as for the coverage multiplicity. These analytical results are essential in validating numerical approximations that are able to simulate more complex configurations.

Download or read book Dissertation Abstracts International written by and published by . This book was released on 2001 with total page 810 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Application of Optimization Techniques to the Design and Maintenance of Satellite Constellations written by James Earl Smith and published by . This book was released on 1999-06-01 with total page 409 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optimization techniques were studied and applied to a variety of applications 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 design a 113:14 repeat ground track variant of the Ellipso(Trademark) inclined elliptical sub- constellation and a gear array variant of the Ellipso(Trademark) equatorial sub- constellation. The resulting optimal constellation designs were found to maintain stability, even when subjected to full perturbation analysis. The global optimization technique of parallel genetic algorithms was also used to create an optimization approach capable of maintaining the designed orbits over specified lengths of time. Although the global method proved successful over short time periods, limitations of the approach eliminated longer time span optimizations and led to the creation of a more operational station keeping optimization scheme. The more operational station keeping implementation yielded similar station keeping estimates while allowing for the study of longer time periods.

Download or read book Innovative Design Manufacturing and Testing of Small Satellites written by Scott Madry and published by Springer. This book was released on 2018-05-12 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book details key trends involving the recent formation of scores of companies that build and launch small satellites or provide key components for small satellite constellations. The applications and usage are quite diverse and include student experiments, serious scientific experimentation, and totally new types of commercial constellations, particularly in telecommunications and remote sensing. The explosive growth in the design, manufacturing, and launch of small satellites is one of the most dynamic aspects in the area of space exploration and exploitation today. New commercial space companies such as Planet Labs, Sky Box, OneWeb, and LeoSat are now building and launching thousands of small satellites and cubesats into orbit. Small companies and big aerospace companies alike are getting into this exciting and interesting new business. This is a practical guide that provides advice to students, researchers, LEO satellite companies, and regulators wrestling with some of the new challenges that small satellites present as more and more companies and countries around the world enter the new small satellite arena.

Download or read book Resource Management in Satellite Networks written by Giovanni Giambene and published by Springer Science & Business Media. This book was released on 2007-04-20 with total page 347 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides significant knowledge on innovative radio resource management schemes for satellite communication systems that exploit lower layer adaptivity and the knowledge of layer 3 IP QoS support and transport layer behavior. The book integrates competencies considering all the parts of system design: propagation aspects, radio resource management, access protocols, network protocols, transport layer protocols, and more, to cover both broadband and mobile satellite systems.

Download or read book Optimization and Valuation of Recongurable Satellite Constellations Under Uncertainty written by Robert S. Legge (Jr.) and published by . This book was released on 2014 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: Space-based persistent surveillance provides decision makers with information necessary to effectively respond to both natural and man-made crises. This thesis investigates a reconfigurable constellation 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 optimization of recongurable satellite constellations specifically tailored to stakeholder objectives while considering requirement uncertainty. The framework is novel in that it avoids many of the assumptions and simplifications of past research by: 1. explicitly considering uncertainty in future operating conditions; 2. concurrently optimizing constellation pattern design, satellite design, and operations design; and, 3. investigating layered and asymmetric patterns. The framework consists of three elements: a detailed simulation model to compute constellation performance and cost for a variety of architectures and patterns, Monte Carlo simulation to determine how well each design performs under uncertain future conditions, and a parallel multi-objective evolutionary algorithm developed from the [epsilon]-NSGA-II genetic algorithm to nd designs that maximize performance while simultaneously minimizing cost. Additionally, a new performance metric is developed to measure directly how well a design meets desired temporal and spatial sampling requirements and a decision model and optimal assignment process is developed to determine how to employ the option of reconfigurability to respond to specific regional events. The framework was used to perform 85 optimization runs selected to compare the cost-effectiveness of several constellation architectures over varied operating conditions and coverage requirements. All optimization runs were performed in less than three months, demonstrating that parallel computing coupled with sophisticated optimization routines enable rapid spiral development of satellite constellations. Results show that recongurable constellations cost 20 to 70% less than similarly performing static constellations for the scenarios studied. The cost savings grows with increasingly demanding coverage requirements. Results from optimizing a fully asymmetric constellation pattern led to two the development of new 'quasi'-asymmetric patterns that were found to significantly outperform symmetric patterns for providing discontinuous coverage. Additionally, results show that the sun-synchronous and rapid launch architectures are the least cost-eective approaches.

Download or read book Reconfigurable Satellite Constellations for Mobile Target Tracking written by Sarah Jo Morgan and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 sources with higher resolution coverage and improved temporal sampling. A ReCon can respond dynamically to different objectives throughout its mission lifetime, offering a more responsive, adaptable alternative to traditional Earth-observing satellite constellations. In the ReCon concept of operations, the constellation is nominally positioned to obtain global coverage. If an event of interest occurs at a particular latitude and longitude location, satellites can be maneuvered to obtain more frequent accesses of this target than otherwise achieved in the nominal configuration. While this architecture has been primarily explored with static ground targets in mind, for more dynamic events of interest, such as hurricanes, an additional layer of responsiveness can be added. A method of mobile target tracking through planning a series of low-thrust maneuvers holds promise. This method has been shown to improve the coverage characteristics of a single satellite in a hurricane case study when compared to a non-maneuvering satellite. This thesis explores and expands upon this concept, reviewing the existing work and applying an alternative approach. Throughout this thesis, procedures for adaptive reconfigurable maneuver planning are laid out and used for two hurricane case studies. This more flexible approach finds solutions for a single satellite case study observing Typhoon Megi using around 2 m/s delta-V, in comparison to similarly performing solutions previously found of around 13.5 m/s delta-V. The inclusion of an optimizer in maneuver planning enhances the prior work, exploring a continuous design space of possible maneuver options. This reveals alternative solutions and a more complete view of the entire design space. This optimization approach also allows a future user to explore the objectives of increased storm access time, closer flyovers, and total delta-V cost of maneuvers. For example, in a single satellite maneuvering case, total target access time can be doubled in comparison to a non-maneuvering case with the use of only around 2.5 m/s delta-V. Overall, this approach has resulted in the exploration of key tradeoffs between these objectives. For example, increased access time or closer passes each come at the cost of increased delta-V requirements; solutions that provide the same total access time require greater delta-V to achieve closer passes and vice versa. When considering the inclusion of multiple maneuvering satellites, diminishing returns of maneuverability are observed, with greater natural accesses occurring with a greater number of satellites in the constellation. Additionally, the concept of executing this method in real time with uncertain targets based upon hurricane forecasts is explored. This reveals the need to incorporate robustness into this optimization. Finally, the prospect of executing this theoretical concept with a ReCon demonstrator is evaluated, including taking into account potential errors in maneuver planning.

Download or read book Uncertainty based Design Optimization and Decision Options for Responsive Maneuvering of Reconfigurable Satellite Constellations written by Charlotte Emily Lowey and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: There are many time-sensitive mission applications for persistent satellite coverage, including dynamic and unpredictable events such as natural disasters, oil spills, extreme weather events, or geopolitical conflicts, which may progress rapidly and require frequently-updated information to co-ordinate the ground response. Reconfigurable satellite constellations can provide on-demand regional coverage by maneuvering orbits to focus passes over the area of interest. In contrast, traditional satellite constellations cannot maneuver to pass over specific ground locations, meaning that achieving persistent coverage spanning all possible locations of interest globally results in a requirement for thousands of satellites. This would present prohibitive costs for many applications, as well as contributing to worsening issues of space traffic management and congestion in Low Earth Orbit (LEO). Incorporating reconfigurability into constellation design allows for responsive maneuvering of satellites into repeating ground tracks (RGTs) over a location of interest, simultaneously reducing the required constellation size by improving the utilization of individual satellites and providing flexibility in the achievable ground coverage. Past work on reconfigurable constellations (ReCon) demonstrated average cost savings of 20-70% compared to iso-performance static constellations, although the complexity of the solution space for the design optimization process limited the maximum size of constellations that could be evaluated. In this thesis, a probabilistic performance metric is developed to compare constellation designs, adopting principles of reliability-based design optimization to quantify the confidence level that reconfigurable designs will outperform iso-cost static alternatives and by what margin of performance. The results show that 74.2% of reconfigurable designs outperform iso-cost static designs with a confidence level of 90% or higher, and with a margin of at least 10% improvement in the level of performance achieved. Computational intensity of the model presents the major constraint upon the size and complexity of simulation cases that may be modelled, so variance reduction techniques are applied to lower the standard error of mean performance in the output, allowing for a reduction in optimization size and runtime while maintaining the same level of error in the predicted results. Decision options for the operational phase of a reconfigurable constellation are presented and assessed to characterize how satellite operators must weigh mission priorities to evaluate trade-offs between propellant conservation and improved coverage of high-value targets.

Download or read book Optimizing Coverage and Revisit Time in Sparse Military Satellite Constellations written by Douglas J. Pegher and published by . This book was released on 2004-09-01 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sparse military satellite constellations were designed using two methods: a traditional approach and a genetic algorithm. One of the traditional constellation designs was the Discoverer II space based radar. Discoverer II was an 8 plane, 24 satellite, Low Earth Orbit (LEO), Walker constellation designed to provide high-range resolution ground moving target indication (HRR-GMTI), synthetic aperture radar (SAR) imaging and high resolution digital terrain mapping. The traditional method designed 9-ball, 12-ball, 18-ball, and 24-ball Walker constellations. The genetic algorithm created constellations by deriving a phenotype from a triploid genotype encoding of orbital elements. The performance of both design methods were compared using a computer simulation. The fitness of each constellation was calculated using maximum gap time, maximum revisit time, and percent coverage. The goal was to determine if one design method would consistently outperform the other. The genetic algorithm offered a fitness improvement over traditional constellation design methods in all cases except the 24-ball constellation where it demonstrated comparable results. The genetic algorithm improvement over the traditional constellations increased as the number of satellites per constellation decreased. A derived equation related revisit time to the number of ship tracks maintained.

Download or read book Decentralized On board Planning and Scheduling for Crosslink enabled Earth observing Constellations written by Warren C. Grunwald and published by . This book was released on 2019 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: Small satellites have improved in capability, nearing a future where high data-rate payloads and crosslinks can provide improved geospatial and temporal coverage, while at a fraction of the cost. Planning and scheduling for efficient bulk data routing with discrete crosslink windows in a dynamic network is a difficult combinatorial optimization problem [30]. As problem size grows, quickly solving the planning and scheduling problem involves implementing algorithms that can leverage parallelization. Decentralized algorithms are inherently parallelizable and can be implemented on-orbit by individual satellites. This thesis investigates a decentralized approach that builds upon the Coupled Constraints Consensus Based Bundle Algorithm (CCBBA) with enhancements to address maximum flow problems. Maximum flow problems occur when moving some resource from sources to sinks across a network, such as a satellite constellation observing targets (sources), moving data between satellites with crosslinks, and down-linking to ground stations (sinks). The CCBBA enhancements include task forking, task outflow coupling, and dynamic task creation based on satellite flow direction preferences. These enhancements increase the total data throughput and decrease required runtime. When implemented on each satellite, this decentralized auction-based approach, named Iterative-CCBBA for Maximum Flow problems (ICMF), provides the following benefits: 1) has robustness in convergence to differences in agent situational awareness, 2) decouples operations from ground station planning resources, and 3) provides an inherently parallelizable algorithm, if implemented on the ground instead of each satellite. ICMF is compared to a state of the art Centralized Global Planner (CGP) in six test cases, with two different inclinations and three different numbers of total satellites. Across all six unique use cases, ICMF has linear scaling in number of consensus rounds and, on average, runs in 94% less time than the CGP, with a 4% improvement in total data volume delivered. ICMF is an effective planner for satellite constellations that value total data throughput and runtime efficiency. The CGP performs better on median latency for observations and median average target age of information, performing better by 58% and 23%, respectively. Future work options for incorporating additional data routing information that could help close the latency and target age of information gap while still using a decentralized approach are presented.

Download or read book A Methodology for the Integrated Design of Small Satellite Constellation Deployment written by Nicholas Husayn Crisp and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: