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Numerical Analysis And Design Of Satellite Constellations For Above The Horizon Coverage
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Book Synopsis Numerical Analysis and Design of Satellite Constellations for Above the Horizon Coverage by : Andrew Takeshi Takano
Download or read book Numerical Analysis and Design of Satellite Constellations for Above the Horizon Coverage written by Andrew Takeshi Takano and published by . This book was released on 2010 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: As near-Earth space becomes increasingly crowded with spacecraft and debris, the need for improved space situational awareness has become paramount. Contemporary ground-based systems are limited in the detection of very small or dim targets. In contrast, space-based systems, above most atmospheric interference, can achieve significant improvements in dim target detection by observing targets against a clutter-free space background, i.e. targets above the horizon (ATH). In this study, numerical methods for the evaluation of ATH coverage provided by constellations of satellites are developed. Analysis of ATH coverage volume is reduced to a planar analysis of cross-sectional coverage area in the orbit plane. The coverage model performs sequences of boolean operations between polygons representing cross-sections of satellite sensor coverage regions and regions of interest, returning the coverage area at the desired multiplicity. This methodology allows investigation of any coverage multiplicity for planar constellations of any size, and use of arbitrary sensor profiles and regions of interest. The implementation is applied to several constellation design problems demonstrating the utility of the numerical ATH coverage model in a constellation design process.
Book Synopsis Optimizing Coverage and Revisit Time in Sparse Military Satellite Constellations: A Comparison of Traditional Approaches and Genetic Algorithms by :
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.
Book Synopsis Satellite Constellations for Worldwide and Hemisphere Coverage by : L. N. Rowell
Download or read book Satellite Constellations for Worldwide and Hemisphere Coverage written by L. N. Rowell and published by . This book was released on 1979 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: Continuous earth-to-space communications require that at least one satellite be in view of the ground station at all times. The satellite constellations discussed in this note are designed to maximize the probability that one or more of the satellites in the constellation will always be at an elevation angle of 20 degrees or more above the horizon of the ground station. (This maximum elevation angle is based on the assumption that millimeter waves will be used for communication.) Constellations of satellites in circular orbits at synchronous and five times synchronous altitude and also in elliptical orbits are presented. Some o of the constellations are designed to maximize global coverage und station located anywhere on earth) and others are designed to maximize coverage for the northern hemisphere. (Author).
Book Synopsis Satellite Constellation Design for Mid-course Ballistic Missile Intercept by : Luke Michael Sauter
Download or read book Satellite Constellation Design for Mid-course Ballistic Missile Intercept written by Luke Michael Sauter and published by . This book was released on 2004 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis will establish a conceptual approach to the design of constellations for satellite-based mid-course missile defense. The ballistic missile intercept problem leads to a new paradigm of coverage where interceptor "reachability" replaces line-of-sight coverage. Interceptors in this concept are limited in their time of flight and AV capabilities. Classical design approaches, based on ground coverage, are employed to provide a priori constellations for ballistic missile defense from a postulated North Korean attack. Both symmetric and asymmetric constellation types, designed for Earth coverage, provide bounds on the number of satellites required. A detailed parametric analysis is used to explore the constellation design space. Various constellation types are optimized to maximize missile defense coverage. Both genetic algorithms and gradient-based optimization techniques are employed. Satellite-based mid-course ballistic missile defense from a regional threat is achievable with as few as 21 satellites. Additional constellation intercept statistics, such as: the number of intercepts per missile, and interceptor closing velocities, are compiled to provide a lethality index. The effective capabilities of these constellations to defend CONUS, beyond the original regional threat, are also explored. It will be demonstrated that the constellations constructed in this work are capable of providing defense from an array of threatening states about the globe. This research illustrates how known design methods and astrodynamics techniques can be used to create new and viable methods of space-based missile defense.
Book Synopsis Mission Design & Implementation of Satellite Constellations by : Jozef C. van der Ha
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.
Book Synopsis Optimizing Coverage and Revisit Time in Sparse Military Satellite Constellations by : Douglas J. Pegher
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.
Book Synopsis Analytical Approach to the Design of Optimal Satellite Constellations for Space-based Space Situational Awareness Applications by : Ashley Darius Biria
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.
Book Synopsis Space Mission Analysis and Design by : Wiley J. Larson
Download or read book Space Mission Analysis and Design written by Wiley J. Larson and published by . This book was released on 1992 with total page 906 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume, appropriate as a textbook for either advanced undergraduate or beginning graduate courses, or as a reference for those already working in space technology, addresses the art and science of preliminary space mission design--beginning with a "blank sheet of paper" and creating a space mission to meet a set of broad, often poorly defined objectives. This revised and updated edition adds new sections on defining the overall mission concept, subject trades, guidance and navigation, and applying the mission analysis and design process to reduce cost and risk in later program stages. This volume also inaugurates the Space Technology Series, a cooperative activity of the US Dept. of Defense and NASA. Annotation copyright by Book News, Inc., Portland, OR
Download or read book Earth Resources written by and published by . This book was released on 1978 with total page 988 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Heterogeneous Satellite Constellation Design for Cislunar Space Situational Awareness Using Real Options Analysis by : Jordan Wachs
Download or read book Heterogeneous Satellite Constellation Design for Cislunar Space Situational Awareness Using Real Options Analysis written by Jordan Wachs and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The number of commercial satellites in Low Earth Orbit (LEO) increased more than four-fold in the decade between 2011 and 2021, a trend that is likely to continue due to the combination of increasingly capable technologies and business models [23] [24]. Building on the success of the LEO economy, there is potential for the establishment of a cislunar economy, supporting NASA and providing commercial goods and services well beyond LEO [20]. Successful creation of a cislunar economy will require commercial and government cooperation at an altogether new scale. The vastness of this new domain, however, makes the implementation of an adequate Space Situational Awareness (SSA) capability both necessary and extraordinarily difficult. Future aerospace leaders may find them selves breaking from traditional paradigms for architecture definition, systems engineering, and program costing [43]. Rather than wholesale abandonment of the processes that resulted in decades of successful innovation, however, future architects will benefit from the adoption of a new framework of systems thinking that combines the hard-won knowledge from the Aerospace domain with similarly deep lessons learned from other domains such as Finance and Real Options. This thesis explores a new framework for the analysis of large, dynamic, heterogeneous satellite constellation architectures by focusing on a multi-mode cislunar (SSA) capability. The combination of technical performance models, financial models, and real options analyses into a single tool allows system architects to identify and maintain multiple paths to program success by preserving flexibility in design and implementation throughout the program life cycle. The analyses presented in this thesis explore how Real Options can be used to increase the probability of mission success from as low as 2% to as high as 72% despite wide ranging uncertainty in system cost and performance.
Book Synopsis Optimal Replacement Policies for Satellite Constellations by : Bradley R. Sumter
Download or read book Optimal Replacement Policies for Satellite Constellations written by Bradley R. Sumter and published by . This book was released on 2003-03 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work considers the problem of finding optimal replacement policies that minimize the expected total cost of maintaining a satellite constellation. The problem is modeled using discrete-time Markov decision processes to determine the replacement policy by allowing the satellite constellation to be in one of a finite number of states at each decision epoch. The constellation stochastically transitions at each time step from one state to another as determined by a set of transition probabilities. At each decision epoch, a decision maker chooses an action from a set of allowable actions for the current system state. A cost associated with each possible action is determined by the number of satellites purchased, launched, or held in storage, as well as the operational capability of the constellation. The system is evaluated for a given time horizon using the standard Policy Evaluation Algorithm of Markov decision processes (stochastic dynamic programming ) to determine the optimal replacement policy and the minimum expected total cost. Example problems using notional data are presented to demonstrate the solution procedures. Sensitivity analysis of problem parameters is performed to investigate their impact on the minimum expected total cost of operating the constellation over a specified time horizon.
Book Synopsis A Phase-based Approach to Satellite Constellation Analysis and Design by : Paul B. DiDomenico
Download or read book A Phase-based Approach to Satellite Constellation Analysis and Design written by Paul B. DiDomenico and published by . This book was released on 1991 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Optimal Coverage of Theater Targets with Small Satellite Constellations by : Axel Rendon
Download or read book Optimal Coverage of Theater Targets with Small Satellite Constellations written by Axel Rendon and published by . This book was released on 2006 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Reconfigurable Satellite Constellations for Mobile Target Tracking by : Sarah Jo Morgan
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.
Book Synopsis Optimization and Valuation of Recongurable Satellite Constellations Under Uncertainty by : Robert S. Legge (Jr.)
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.
Book Synopsis Infrared Spaceborne Remote Sensing by :
Download or read book Infrared Spaceborne Remote Sensing written by and published by . This book was released on 1995 with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Internetworking and Computing Over Satellite Networks by : Yongguang Zhang
Download or read book Internetworking and Computing Over Satellite Networks written by Yongguang Zhang and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: The emphasis of this text is on data networking, internetworking and distributed computing issues. The material surveys recent work in the area of satellite networks, introduces certain state-of-the-art technologies, and presents recent research results in these areas.
