Download or read book Thermospheric Density and Wind Determination from Satellite Dynamics written by Eelco Doornbos and published by Springer Science & Business Media. This book was released on 2012-01-19 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Earth's atmosphere is often portrayed as a thin and finite blanket covering our planet, separate from the emptiness of outer space. In reality, the transition is gradual and a tiny fraction of the atmophere gases is still present at the altitude of low orbiting satellites. The very high velocities of these satellites ensure that their orbital motion can still be considerably affected by air density and wind. This influence can be measured using accelerometers and satellite tracking techniques. The opening chapters of this thesis provide an excellent introduction to the various disciplines that are involved in the interpretation of these observations: orbital mechanics, satellite aerodynamics and upper atmospheric physics. A subsequent chapter, at the heart of this work, covers advances in the algorithms used for processing satellite accelerometry and Two-Line Element (TLE) orbit data. The closing chapters provide an elaborate analysis of the resulting density and wind products, which are generating many opportunities for further research, to improve the modelling and understanding of the thermosphere system and its interactions with the lower atmosphere, the ionosphere-magnetosphere system and the Sun.

Download or read book Thermospheric Density and Wind Determination from Satellite Dynamics written by Eelco Doornbos and published by Springer Science & Business Media. This book was released on 2012-01-19 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Earth's atmosphere is often portrayed as a thin and finite blanket covering our planet, separate from the emptiness of outer space. In reality, the transition is gradual and a tiny fraction of the atmophere gases is still present at the altitude of low orbiting satellites. The very high velocities of these satellites ensure that their orbital motion can still be considerably affected by air density and wind. This influence can be measured using accelerometers and satellite tracking techniques. The opening chapters of this thesis provide an excellent introduction to the various disciplines that are involved in the interpretation of these observations: orbital mechanics, satellite aerodynamics and upper atmospheric physics. A subsequent chapter, at the heart of this work, covers advances in the algorithms used for processing satellite accelerometry and Two-Line Element (TLE) orbit data. The closing chapters provide an elaborate analysis of the resulting density and wind products, which are generating many opportunities for further research, to improve the modelling and understanding of the thermosphere system and its interactions with the lower atmosphere, the ionosphere-magnetosphere system and the Sun.

Download or read book Practical Astrodynamics written by Alessandro de Iaco Veris and published by Springer. This book was released on 2017-11-28 with total page 1320 pages. Available in PDF, EPUB and Kindle. Book excerpt: This modern textbook guides the reader through the theory and practice of the motion and attitude control of space vehicles. It first presents the fundamental principles of spaceflight mechanics and then addresses more complex concepts and applications of perturbation theory, orbit determination and refinement, space propulsion, orbital maneuvers, interplanetary trajectories, gyroscope dynamics, attitude control, and rocket performance. Many algorithms used in the modern practice of trajectory computation are also provided. The numerical treatment of the equations of motion, the related methods, and the tables needed to use them receive particular emphasis. A large collection of bibliographical references (including books, articles, and items from the "gray literature") is provided at the end of each chapter, and attention is drawn to many internet resources available to the reader. The book will be of particular value to undergraduate and graduate students in aerospace engineering.

Download or read book Spacecraft Dynamics and Control written by Enrico Canuto and published by Butterworth-Heinemann. This book was released on 2018-03-08 with total page 792 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spacecraft Dynamics and Control: The Embedded Model Control Approach provides a uniform and systematic way of approaching space engineering control problems from the standpoint of model-based control, using state-space equations as the key paradigm for simulation, design and implementation. The book introduces the Embedded Model Control methodology for the design and implementation of attitude and orbit control systems. The logic architecture is organized around the embedded model of the spacecraft and its surrounding environment. The model is compelled to include disturbance dynamics as a repository of the uncertainty that the control law must reject to meet attitude and orbit requirements within the uncertainty class. The source of the real-time uncertainty estimation/prediction is the model error signal, as it encodes the residual discrepancies between spacecraft measurements and model output. The embedded model and the uncertainty estimation feedback (noise estimator in the book) constitute the state predictor feeding the control law. Asymptotic pole placement (exploiting the asymptotes of closed-loop transfer functions) is the way to design and tune feedback loops around the embedded model (state predictor, control law, reference generator). The design versus the uncertainty class is driven by analytic stability and performance inequalities. The method is applied to several attitude and orbit control problems. The book begins with an extensive introduction to attitude geometry and algebra and ends with the core themes: state-space dynamics and Embedded Model Control Fundamentals of orbit, attitude and environment dynamics are treated giving emphasis to state-space formulation, disturbance dynamics, state feedback and prediction, closed-loop stability Sensors and actuators are treated giving emphasis to their dynamics and modelling of measurement errors. Numerical tables are included and their data employed for numerical simulations Orbit and attitude control problems of the European GOCE mission are the inspiration of numerical exercises and simulations The suite of the attitude control modes of a GOCE-like mission is designed and simulated around the so-called mission state predictor Solved and unsolved exercises are included within the text - and not separated at the end of chapters - for better understanding, training and application Simulated results and their graphical plots are developed through MATLAB/Simulink code

Download or read book Continuing Kepler s Quest written by National Research Council and published by National Academies Press. This book was released on 2012-09-06 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: In February 2009, the commercial communications satellite Iridium 33 collided with the Russian military communications satellite Cosmos 2251. The collision, which was not the first recorded between two satellites in orbit-but the most recent and alarming-produced thousands of pieces of debris, only a small percentage of which could be tracked by sensors located around the world. In early 2007, China tested a kinetic anti-satellite weapon against one of its own satellites, which also generated substantial amounts of space debris. These collisions highlighted the importance of maintaining accurate knowledge, and the associated uncertainty, of the orbit of each object in space. These data are needed to predict close approaches of space objects and to compute the probability of collision so that owners/operators can decide whether or not to make a collision avoidance maneuver by a spacecraft with such capability. The space object catalog currently contains more than 20,000 objects, and when the planned space fence radar becomes operational this number is expected to exceed 100,000. A key task is to determine if objects might come closer to each other, an event known as "conjunction," and the probability that they might collide. The U.S. Air Force is the primary U.S. government organization tasked with maintaining the space object catalog and data on all space objects. This is a complicated task, involving collecting data from a multitude of different sensors-many of which were not specifically designed to track orbiting objects-and fusing the tracking data along with other data, such as data from atmospheric models, to provide predictions of where objects will be in the future. The Committee for the Assessment of the U.S. Air Force's Astrodynamic Standards collected data and heard from numerous people involved in developing and maintaining the current astrodynamics standards for the Air Force Space Command (AFSPC), as well as representatives of the user community, such as NASA and commercial satellite owners and operators. Preventing collisions of space objects, regardless of their ownership, is in the national security interested of the United States. Continuing Kepler's Quest makes recommendations to the AFSPC in order for it to create and expand research programs, design and develop hardware and software, as well as determine which organizations to work with to achieve its goals.

Download or read book China Satellite Navigation Conference CSNC 2015 Proceedings Volume III written by Jiadong Sun and published by Springer. This book was released on 2015-04-21 with total page 843 pages. Available in PDF, EPUB and Kindle. Book excerpt: China Satellite Navigation Conference (CSNC) 2015 Proceedings presents selected research papers from CSNC2015, held during 13th-15th May in Xian, China. The theme of CSNC2015 is Opening-up, Connectivity and Win-win. These papers discuss the technologies and applications of the Global Navigation Satellite System (GNSS), and the latest progress made in the China BeiDou System (BDS) especially. They are divided into 10 topics to match the corresponding sessions in CSNC2015, which broadly covered key topics in GNSS. Readers can learn about the BDS and keep abreast of the latest advances in GNSS techniques and applications. SUN Jiadong is the Chief Designer of the Compass/ BDS, and the academician of Chinese Academy of Sciences (CAS); LIU Jingnan is a professor at Wuhan University. FAN Shiwei is a researcher at China Satellite Navigation Office; LU Xiaochun is an academician of Chinese Academy of Sciences (CAS).

Download or read book Conceptual Shape Optimization of Entry Vehicles written by Dominic Dirkx and published by Springer. This book was released on 2016-12-09 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the parameterization of entry capsules, including Apollo capsules and planetary probes, and winged entry vehicles such as the Space Shuttle and lifting bodies. The aerodynamic modelling is based on a variety of panel methods that take shadowing into account, and it has been validated with flight and wind tunnel data of Apollo and the Space Shuttle. The shape optimization is combined with constrained trajectory analysis, and the multi-objective approach provides the engineer with a Pareto front of optimal shapes. The method detailed in Conceptual Shape Optimization of Entry Vehicles is straightforward, and the output gives the engineer insight in the effect of shape variations on trajectory performance. All applied models and algorithms used are explained in detail, allowing for reconstructing the design tool to the researcher’s requirements. Conceptual Shape Optimization of Entry Vehicles will be of interest to both researchers and graduate students in the field of aerospace engineering, and to practitioners within the aerospace industry.

Download or read book Variability of the Lower Thermosphere Determined from Satellite Accelerometer Data written by Frank A. Marcos and published by . This book was released on 1978 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: An extensive atmospheric density data base has been developed using accelerometer results from four low altitude satellites. The altitude range of the data is from 250 km down to as low as 140 km, with latitude coverage from 90 N to 90 S and local time periods that cover several 24-hr cycles. The data were obtained over a wide range of geomagnetic activity conditions. Solar radiation, as indicated by the 10.7-cm flux, was generally very low. Hence the data base applies mainly to solar minimum conditions. A description of the satellites, the accelerometer experiment, and the data base is given. Density variability is statistically analyzed in relation to selected atmospheric models. Particular attention is given to deviations from a normal distribution. Frequency distribitons of the data are described in terms of the mean value and the second, third, and fourth moments about the mean. This provides a more accurate description of extreme variations. The statistical properties of atmospheric variability are analyzed as a function of geomagnetic activity, latitude, altitude, and local time to develop a quantitative knowledge of unmodeled density variations. The results show that these accelerometer data will permit significant improvement in understanding the variations in the lower thermospheric density.

Download or read book Modeling the Ionosphere Thermosphere written by J. D. Huba and published by John Wiley & Sons. This book was released on 2014-03-17 with total page 735 pages. Available in PDF, EPUB and Kindle. Book excerpt: Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 201. Modeling the Ionosphere-Thermosphere System brings together for the first time a detailed description of the physics of the IT system in conjunction with numerical techniques to solve the complex system of equations that describe the system, as well as issues of current interest. Volume highlights include discussions of: Physics of the ionosphere and thermosphere IT system, and the numerical methods to solve the basic equations of the IT system The physics and numerical methods to determine the global electrodynamics of the IT system The response of the IT system to forcings from below (i.e., the lower atmosphere) and from above (i.e., the magnetosphere) The physics and numerical methods to model ionospheric irregularities Data assimilation techniques, comparison of model results to data, climate variability studies, and applications to space weather Providing a clear description of the physics of this system in several tutorial-like articles, Modeling the Ionosphere-Thermosphere System is of value to the upper atmosphere science community in general. Chapters describing details of the numerical methods used to solve the equations that describe the IT system make the volume useful to both active researchers in the field and students.

Download or read book Thermospheric Winds and Their Influence on the Ionosphere written by R. Rüster and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is well known that thermospheric winds play an important role in the dynamics of the upper atmo sphere and are of major importance for the behaviour of the ionosphere. The methods of calculating these winds are discussed briefly. Comparisons of the calculated winds with observational data are carried out. Some main effects of the winds on the dynamical behaviour of the ionized as well as neutral part of the upper atmosphere are discussed. 2. Calculation of thermospheric winds The system of equations describing the dynamical behaviour of the thermosphere and the ionosphere consists of: b a neutral atmosphere ionosphere continuity equations continuity equations for different ion species and electrons equations of motion (winds) equations of motion for the different constituents (ambi polar diffusion, wind induced drifts, ~ x ~ -drifts) energy balance equations energy balance equations Due to collisions between charged and neutral particles there is an interaction between the ionized and neutral gas. Both sets of equations are coupled, therefore, by the respective drag terms. Because of the complexity of the mathematics involved in solving all equations simultaneously, different approaches have been made to solve parts of this system of differential equations under additional assumptions and restrictions. There are two general approaches: a. ) Solution of the equation of motion of the neutral atmosphere together with the ionospheric continuity equations and equations of motion of the ions.

Download or read book Space Physics and Aeronomy Space Weather Effects and Applications written by Philip J. Erickson and published by John Wiley & Sons. This book was released on 2021-04-06 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Examines how solar and terrestrial space phenomena affect sophisticated technological systems Contemporary society relies on sophisticated technologies to manage electricity distribution, communication networks, transportation safety, and myriad other systems. The successful design and operation of both ground-based and space-based systems must consider solar and terrestrial space phenomena and processes. Space Weather Effects and Applications describes the effects of space weather on various present-day technologies and explores how improved instrumentation to measure Earth's space environment can be used to more accurately forecast changes and disruptions. Volume highlights include: Damage and disruption to orbiting satellite equipment by solar particles and cosmic rays Effects of space radiation on aircraft at high altitudes and latitudes Response of radio and radar-based systems to solar bursts Disturbances to the propagation of radio waves caused by space weather How geomagnetic field changes impact ground-based systems such as pipelines Impacts of human exposure to the space radiation environment The American Geophysical Union promotes discovery in Earth and space science for the benefit of humanity. Its publications disseminate scientific knowledge and provide resources for researchers, students, and professionals. Find out more about the Space Physics and Aeronomy collection in this Q&A with the Editors in Chief

Download or read book Feasibility Study for an Atmospheric Density Specification Satellite written by T. L. Killeen and published by . This book was released on 1989 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of the Atmospheric Density Specification (ADS) mission (AFGL-705) is to generate a coordinated and comprehensive global set of lower thermospheric state variables (density, temperature, and wind) in the altitude range 100 - 300 kilometers. This data set will be analyzed by a team of scientists including experimentalists and theoreticians to improve the performance of the density specification models of this region of the atmosphere, which currently provide density predictions to a typical accuracy of approx. 15 percent. The instrument complement of the proposed mission includes an ion/neutral mass spectrometer capable of determining absolute neutral densities to approx. 5 percent, an electrostatic triaxial accelerometer for satellite drag and cross-track wind determination, a Fabry-Perot interferometer for the determination of altitude profiles of vector winds, temperatures and composition, and an ion mass spectrometer capable of determining neutral winds and ion neutral constituent abundances.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1991 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Atmosphere and Climate of Mars written by Robert M. Haberle and published by Cambridge University Press. This book was released on 2017-06-29 with total page 613 pages. Available in PDF, EPUB and Kindle. Book excerpt: Humanity has long been fascinated by the planet Mars. Was its climate ever conducive to life? What is the atmosphere like today and why did it change so dramatically over time? Eleven spacecraft have successfully flown to Mars since the Viking mission of the 1970s and early 1980s. These orbiters, landers and rovers have generated vast amounts of data that now span a Martian decade (roughly eighteen years). This new volume brings together the many new ideas about the atmosphere and climate system that have emerged, including the complex interplay of the volatile and dust cycles, the atmosphere-surface interactions that connect them over time, and the diversity of the planet's environment and its complex history. Including tutorials and explanations of complicated ideas, students, researchers and non-specialists alike are able to use this resource to gain a thorough and up-to-date understanding of this most Earth-like of planetary neighbours.

Download or read book Beyond 100 The Next Century in Geodesy written by Jeffrey T. Freymueller and published by Springer Nature. This book was released on 2022-10-24 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book contains 30 peer-reviewed papers based on presentations at the 27th General Assembly of the International Union of Geodesy and Geophysics (IUGG). The meeting was held from July 8 to 18, 2019 in Montreal, Canada, with the theme being the celebration of the centennial of the establishment of the IUGG. The centennial was also a good opportunity to look forward to the next century, as reflected in the title of this volume. The papers in this volume represent a cross-section of present activity in geodesy, and highlight the future directions in the field as we begin the second century of the IUGG. During the meeting, the International Association of Geodesy (IAG) organized one Union Symposium, 6 IAG Symposia, 7 Joint Symposia with other associations, and 20 business meetings. In addition, IAG co-sponsored 8 Union Symposia and 15 Joint Symposia. In total, 3952 participants registered, 437 of them with IAG priority. In total, there were 234 symposia and 18 Workshops with 4580 presentations, of which 469 were in IAG-associated symposia.

Download or read book Satellite Orbits written by Oliver Montenbruck and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: This modern presentation guides readers through the theory and practice of satellite orbit prediction and determination. Starting from the basic principles of orbital mechanics, it covers elaborate force models as well as precise methods of satellite tracking. The accompanying CD-ROM includes source code in C++ and relevant data files for applications. The result is a powerful and unique spaceflight dynamics library, which allows users to easily create software extensions. An extensive collection of frequently updated Internet resources is provided through WWW hyperlinks.

Download or read book Dawn Dusk Asymmetries in Planetary Plasma Environments written by Stein Haaland and published by John Wiley & Sons. This book was released on 2017-10-30 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dawn­Dusk Asymmetries in Planetary Plasma Environments Dawn-dusk asymmetries are ubiquitous features of the plasma environment of many of the planets in our solar system. They occur when a particular process or feature is more pronounced at one side of a planet than the other. For example, recent observations indicate that Earth's magnetopause is thicker at dawn than at dusk. Likewise, auroral breakups at Earth are more likely to occur in the pre-midnight than post-midnight sectors. Increasing availability of remotely sensed and in situ measurements of planetary ionospheres, magnetospheres and their interfaces to the solar wind have revealed significant and persistent dawn-dusk asymmetries. As yet there is no consensus regarding the source of many of these asymmetries, nor the physical mechanisms by which they are produced and maintained. Volume highlights include: A comprehensive and updated overview of current knowledge about dawn-dusk asymmetries in the plasma environments of planets in our solar system and the mechanisms behind them Valuable contributions from internationally recognized experts, covering both observations, simulations and theories discussing all important aspects of dawn-dusk asymmetries Space weather effects are caused by processes in space, mainly the magnetotail, and can be highly localized on ground. Knowing where the source, i.e., where dawn-dusk location is will allow for a better prediction of where the effects on ground will be most pronounced Covering both observational and theoretical aspects of dawn dusk asymmetries, Dawn­-Dusk Asymmetries in Planetary Plasma Environments will be a valuable resource for academic researchers in space physics, planetary science, astrophysics, physics, geophysics and earth science.